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  • Astrophysics  (196)
  • Biochemistry and Biotechnology
  • Cell & Developmental Biology
  • Fisheries
  • Inorganic Chemistry
  • 2005-2009  (222)
  • 1950-1954
  • 2005  (222)
  • 1
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    Fisheries Science Collaborations: The Critical Role of the Community (2005)
    Details
    Publication Date: 2021-05-19
    Description: The present paper is based on a collation of information, through both a literature review and an internet search, on North American programs that involve some kind of scientific collaboration between fishers and fisheries scientists. It identifies four basic models of such collaboration and offers examples of collaborative activities that seem to fit into each of them. The first model defers to the expertise of the scientist for all major decisions and creates a strong programmatic distinction between what is science, and shall be done by scientists, and what are other, related activities that can be carried out by others. Various kinds of tagging programs, fisher advisory boards, at-sea research collaboration and many other activities fit this model. The second model, traditional ecological knowledge, recognizes that fishers have available to them a unique, local knowledge of the resource that can make a supplementary contribution to fisheries science. Several government, community and environmental groups are engaged in finding, recording and using this knowledge....
    Description: Unpublished
    Keywords: Mariculture ; Fisheries
    Repository Name: AquaDocs
    Type: Conference Material , Non-Refereed , Paper
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  • 2
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    Report of the meeting: Third Meeting of the Preparatory Committee For the Preparation of the Partnership Conference: Mauritius, 01 November 1999 (2005)
    ACOPS
    Details
    Publication Date: 2021-01-30
    Description: Dr Sebek introduced the ACOPS report which sums up the activities undertaken since the last Preparatory Committee meeting all of which are detailed in Annex V. In particular, Dr Sebek said that several strategic partnerships were being forged in order that certain components of the work programme, as agreed at the First Preparatory Committee Meeting in Nairobi in February, could start as soon as possible. A good example of such a policy, in the field of root cause analyses was the anticipated co-operation with UNESCO.
    Description: Published
    Keywords: Fisheries
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
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  • 3
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    Interaction of Marine Turtles with Fisheries in the Mediterranean (2005)
    UNEP; Regional Activity Centre for Specially Protected Areas (RAC/SPA)
    Details
    Publication Date: 2021-05-19
    Description: At present, the impact of accidental catch on sea turtle populations is one of the most urgent problems that must be solved to ensure the survival of all these species worldwide. In the Mediterranean, too, all marine turtle species are affected by fishing activities, in particular the loggerhead (Caretta caretta) and the green (Chelonia mydas) turtles, which are more common than the others and are the only ones breeding in this sea. Since the Mediterranean populations of both species seem to be genetically isolated from the Atlantic ones (Bowen et al., 1992; Bowen et al., 1993; Laurent et al., 1993), fishing-induced mortality probably cannot be counterbalanced by immigration. This implies that the survival of the Mediterranean populations of these species depends to a great extent on the conservation effort that the Mediterranean countries carry on in the near future to reduce accidental mortality.
    Description: Unpublished
    Keywords: Marine turtles ; Fisheries
    Repository Name: AquaDocs
    Type: Working Paper , Non-Refereed
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  • 4
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    Emptying the Ocean: The threatened fisheries of West Africa (2005)
    Details
    Publication Date: 2021-05-19
    Description: The coastal waters of West Africa are among the world's richest fishing grounds ... for the time being. Droughts have ravaged the hinterland and as a result people have steadily moved towards the shores of Senegal and Mauritania. At the same time the international fishing industry seems intent on exploiting West African waters to a greater and greater extent. Nicolien Zuijdgeest and photographer Bas Beentjes visited the region and found that the sustainability of fisheries is being seriously threatened.
    Description: Published
    Keywords: Fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution , Non-Refereed , Article
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  • 5
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    Gestion des Peches, de la Biodiversite et de L’environnement au Gabon (2005)
    Fishbase
    Details
    Publication Date: 2021-05-19
    Description: Le Gabon est situé en Afrique centrale avec une façade atlantique . Il est limité au Nord par le Cameroun, au Nord-ouest par la Guinée Equatoriale, à l’Est et au Sud par le Congo. La zone économique exclusive (ZEE) a une surface de 213.000 Km². elle est plus vaste que celle de Sao-Tomé et Principé, pays insulaire voisin (160.000 Km²). La façade maritime à une longueur de 750 Km , de Coccobeach à Ndindi. La largeur moyenne du plateau continental est de 60 Km, soit une surface à peu-près de 40.600 Km² de la côte à l’isobathe de 200 mètres. Ce plateau se termine par un talus peu abrupt, d’une longueur de 750 Km et d’une superficie de 11.200 Km² entre 200 et 800 mètres de profondeur....
    Description: Unpublished
    Keywords: Biodiversity ; Environments ; Fisheries
    Repository Name: AquaDocs
    Type: Working Paper , Non-Refereed
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  • 6
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    Biodiversity, Trade, And The Fishing Sector Case Study: West Africa (2005)
    Details
    Publication Date: 2021-05-19
    Description: In 1997, IUCN-The World Conservation Union, with the financial support of the German Federal Ministry for Economic Co-operation and Development, initiated a project to examine the relationship between the Convention on Biological Diversity (CBD) and the rules of international trade–those administered by the World Trade Organisation (WTO), in particular. The project was motivated by a widely shared concern that the aims of the CBD, which are essentially to conserve and equitably distribute the benefits of the environment, might be undermined by the WTO, which aims at the liberalisation of trade. Liberalised trade has the potential to integrate economies, regionally and globally, in mutually beneficial ways. But some observers are concerned that it may do so at a cost of impairing the environment and amplifying disparities in wealth, much of which, in poorer nations, is disproportionately represented in endowments of natural resources. Other commentators have claimed to locate synergistic potential, suggesting, for example, that trade law’s anti-subsidy disciplines might be conscripted into the campaign against environmental abuses such as overfishing.
    Keywords: Biodiversity ; International trade ; Fisheries
    Repository Name: AquaDocs
    Type: Conference Material , Non-Refereed , Paper
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  • 7
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    Marine biological research in Mozambique: past, present and future (2005)
    Royal Academy of Sciences
    Details
    Publication Date: 2021-05-19
    Description: This synopsis describes the development of marine biological research, including fisheries, in Mozambique. With around 3000 km of coastline, the living resources of the sea playa major role in the Mozambican society, mainly as a source of protein and income for the population, and of foreign revenue through exports. In the first years, after independence, in 1975, research activities in marine sciences were limited and mainly concentrated to fisheries through cooperation with Norway and the Soviet Union. A new era for biology started in 1985 when the Faculty of Biology at Universidade Eduardo Mondlane was re-opened. A 5yr curriculum towards a licentiate degree was introduced with a strong marine profile. Since the 1990s, a very dynamic de-velopment in Mozambican marine biological research has occurred. Several academic degrees in marine biology from universities abroad were obtained, and local expertise developed; building vital institutions and enrolling in advanced research activities.
    Description: Published
    Keywords: Marine biology ; Fisheries
    Repository Name: AquaDocs
    Type: Journal Contribution , Refereed , Article
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  • 8
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    The Fisheries of Eritrea (2005)
    FAO
    Details
    Publication Date: 2021-01-30
    Description: Published
    Description: Eritrea
    Keywords: Fisheries
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
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  • 9
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    Rapport de la septième rencontre de travail IMROP/IEO pour l’étude des pêcheries de crustacés. (2005)
    IMROP/IEO
    Details
    Publication Date: 2021-05-19
    Description: Cette rencontre entre dans le cadre du programme conjoint de recherche sur les crustacés entre l’IMROP et l’IEO (Espagne)
    Description: Published
    Keywords: Captures ; Effort de pêche ; Length distribution ; Fishing effort ; CPUE ; Débarquement ; Landing ; Pêcheries ; Mauritanie ; Fisheries ; Accords de pêche ; UE ; Mauritania ; Crevettes ; Shrimps ; EU ; Distribution de taille ; Fishing fleet ; Fishing agreements ; Flottille de pêche ; Catches ; Crustacean fisheries
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
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  • 10
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    Fish for Thought: Fisheries, International Trade and Sustainable Development (2005)
    International Centre for Trade and Sustainable Development (ICTSD) and IUCN-The World Conservation Union
    Details
    Publication Date: 2021-05-19
    Description: The Fisheries, International Trade, and Sustainable Development programme aims to inject both the sustainable development and natural resource management perspectives into the debate on trade and fisheries. The ultimate objective of the programme is to make international trade in fisheries supportive of sustainable development. The programme's main activity will be to convene a series of policy dialogues on fisheries, international trade, and sustainable development which will link processes and actors, and bring together all the different stakeholders' perspectives. Initially the programme aims to facilitate a process in which each stakeholder can move beyond the constraints inherent in his or her position, to enable all participants to step back from particular debates and stand-offs regarding fisheries, trade, and sustainable development-related issues such as subsidies, ecolabelling, or conservation measures. The dialogues, research, and information exchange process will seek to build common understanding and a baseline of shared information, and pave the way for participating stakeholders to seek solutions compatible with the aims of sustainable development by exploring ways to improve resource management while safeguarding the livelihoods of those who depend on fisheries, and ensuring economic growth for developing countries.
    Description: International Centre for Trade and Sustainable Development, IUCN — The World Conservation Union Publications Service Unit
    Description: Published
    Keywords: Sustainable development ; Fisheries ; International trade
    Repository Name: AquaDocs
    Type: Book Section , Non-Refereed
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  • 11
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    Focus on the Marine fisheries Research Division (2005)
    Accra : Marine Fisheries Research Division
    Details
    Publication Date: 2021-05-19
    Description: Ministry of Food and Agriculture
    Description: Directorate of Fisheries
    Description: Published
    Description: Exploitation, Upwelling, Pelagic species, Demersal species, Atlantic Ocean
    Keywords: Fishery policy ; Marine environment ; Fisheries ; Exploitation
    Repository Name: AquaDocs
    Type: Report , Non-Refereed
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  • 12
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    African Fisheries: Major Trends and Diagnostic of the 20th Century. (2005)
    IIFET
    Details
    Publication Date: 2021-05-19
    Description: The marine fisheries production from African coastal countries, combined with that of freshwater production of the continent is estimated to be 6 millions metric tons, corresponding only 5 % of the total world production. Africa's contribution to fisheries products (1,5 %) is insignificant compared to that of world commerce which is around 44 millions tons. This deplorable situation is due to a certain number of problems which include s among others, the relative biogenic poverty of African waters, the exploitation of African waters by foreign vessels, the total lack of catches effected by the African vessels out of their regional boundaries, the lack of knowledge on the mastering of commercialisation and on veritable commercial politics of fisheries products, including quality assurance. In addition to this, the almost inexistence of the aquaculture in the sub-Saharan countries. This paper analyses the African fisheries in the whole continent and presents the general characters, notably its evolution, fisheries resources, valorisation and consumption of fisheries products. The global analysis made here accords a priority to markets as well as to the framework of contribution of these products and tries, at the end of the 20th century, to present some trends. Facing the globalisation phenomena, how will African fisheries producers be challenged in the new millennium? This continental level analysis brings out field application and some different development perspectives for both small scale and industrial fisheries sub-sectors.
    Description: Published
    Keywords: Fisheries
    Repository Name: AquaDocs
    Type: Proceedings Paper , Non-Refereed
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  • 13
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    Ecology. Fish moved by warming waters (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-05-14
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Inman, Mason -- New York, N.Y. -- Science. 2005 May 13;308(5724):937.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15890852" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Climate ; *Ecosystem ; Environment ; Fisheries ; *Fishes ; North Sea ; Population Dynamics ; *Seawater ; Temperature
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 14
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    Ecology. North Atlantic right whales in crisis (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-07-26
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kraus, Scott D -- Brown, Moira W -- Caswell, Hal -- Clark, Christopher W -- Fujiwara, Masami -- Hamilton, Philip K -- Kenney, Robert D -- Knowlton, Amy R -- Landry, Scott -- Mayo, Charles A -- McLellan, William A -- Moore, Michael J -- Nowacek, Douglas P -- Pabst, D Ann -- Read, Andrew J -- Rolland, Rosalind M -- New York, N.Y. -- Science. 2005 Jul 22;309(5734):561-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Edgerton Research Laboratory, New England Aquarium, Boston, MA 02110-3399, USA. skraus@neaq.org〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16040692" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Atlantic Ocean ; Ecology ; *Ecosystem ; Environment ; Female ; Fisheries ; Male ; Mortality ; Population Dynamics ; Population Growth ; Public Policy ; Reproduction ; Ships ; *Whales/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 15
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    Global patterns of predator diversity in the open oceans (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-07-30
    Description: The open oceans comprise most of the biosphere, yet patterns and trends of species diversity there are enigmatic. Here, we derive worldwide patterns of tuna and billfish diversity over the past 50 years, revealing distinct subtropical "hotspots" that appeared to hold generally for other predators and zooplankton. Diversity was positively correlated with thermal fronts and dissolved oxygen and a nonlinear function of temperature (approximately 25 degrees C optimum). Diversity declined between 10 and 50% in all oceans, a trend that coincided with increased fishing pressure, superimposed on strong El Nino-Southern Oscillation-driven variability across the Pacific. We conclude that predator diversity shows a predictable yet eroding pattern signaling ecosystem-wide changes linked to climate and fishing.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Worm, Boris -- Sandow, Marcel -- Oschlies, Andreas -- Lotze, Heike K -- Myers, Ransom A -- New York, N.Y. -- Science. 2005 Aug 26;309(5739):1365-9. Epub 2005 Jul 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biology Department, Dalhousie University, Halifax, NS, Canada B3H 4J1. bworm@dal.ca〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16051749" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biodiversity ; Climate ; *Ecosystem ; Fisheries ; Oceans and Seas ; Oxygen/analysis ; *Perciformes ; Population Density ; *Predatory Behavior ; Regression Analysis ; Seasons ; Temperature ; Time Factors ; *Tuna ; Zooplankton
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 16
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    Edward Ames profile. Uncovering the hidden paths of Maine's threatened cod (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-11-19
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bhattacharjee, Yudhijit -- New York, N.Y. -- Science. 2005 Nov 18;310(5751):1110-1.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16293737" target="_blank"〉PubMed〈/a〉
    Keywords: Animal Migration ; Animals ; Conservation of Natural Resources/*history ; Fisheries ; *Gadus morhua/physiology ; History, 20th Century ; History, 21st Century ; Maine ; Public Policy ; Reproduction
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 17
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    Bilateral action for right whales (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-12-13
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sayles, Jesse S -- Green, David M -- New York, N.Y. -- Science. 2005 Dec 9;310(5754):1616-8; author reply 1616-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16339430" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Atlantic Ocean ; Canada ; *Ecosystem ; Environment ; Fisheries ; *International Cooperation ; Mortality ; Population Dynamics ; Public Policy ; Ships ; United States ; *Whales
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 18
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    Trophic cascades in a formerly cod-dominated ecosystem (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-06-11
    Description: Removal of top predators from ecosystems can result in cascading effects through the trophic levels below, completely restructuring the food web. Cascades have been observed in small-scale or simple food webs, but not in large, complex, open-ocean ecosystems. Using data spanning many decades from a once cod-dominated northwest Atlantic ecosystem, we demonstrate a trophic cascade in a large marine ecosystem. Several cod stocks in other geographic areas have also collapsed without recovery, suggesting the existence of trophic cascades in these systems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Frank, Kenneth T -- Petrie, Brian -- Choi, Jae S -- Leggett, William C -- New York, N.Y. -- Science. 2005 Jun 10;308(5728):1621-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Fisheries and Oceans, Bedford Institute of Oceanography, Ocean Sciences Division, Post Office Box 1006, Dartmouth, Nova Scotia, B2Y 4A2, Canada. frankk@mar.dfo-mpo.gc.ca〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15947186" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Atlantic Ocean ; Biodiversity ; Biomass ; *Ecosystem ; Fisheries ; *Fishes ; *Food Chain ; Gadus morhua ; *Invertebrates ; *Phytoplankton ; Population Density ; Population Dynamics ; Predatory Behavior ; Principal Component Analysis ; Seals, Earless ; *Seawater ; Time Factors ; *Zooplankton
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 19
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    Ecosystem management. California tries to connect its scattered marine reserves (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-04-23
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Avasthi, Amitabh -- New York, N.Y. -- Science. 2005 Apr 22;308(5721):487-8.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15845821" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biodiversity ; California ; *Conservation of Natural Resources ; *Ecosystem ; Environment ; Fisheries ; *Fishes ; Marine Biology ; *Seawater
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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  • 20
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    Jellyfish blooms in the Yangtze Estuary (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-01-08
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Xian, Weiwei -- Kang, Bin -- Liu, Ruiyu -- New York, N.Y. -- Science. 2005 Jan 7;307(5706):41.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15637253" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; China ; *Ecosystem ; Fisheries ; Fishes ; *Rivers ; Scyphozoa/*growth & development ; Seasons ; Seawater
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 21
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    Ecology. Ecosystem services (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-04-02
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stokstad, Erik -- New York, N.Y. -- Science. 2005 Apr 1;308(5718):41-3.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15802579" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biodiversity ; Conservation of Natural Resources ; Costs and Cost Analysis ; Developed Countries ; Developing Countries ; *Ecology/methods ; *Ecosystem ; *Environment ; Eutrophication ; Fisheries ; Humans ; International Cooperation ; Poverty ; Public Policy ; Trees
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 22
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    Science in Iran. Attack of the killer jellies (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-09-17
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stone, Richard -- New York, N.Y. -- Science. 2005 Sep 16;309(5742):1805-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16166491" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biomass ; *Ctenophora/growth & development/physiology ; *Ecosystem ; Feeding Behavior ; Fisheries ; Fishes ; Food Chain ; International Cooperation ; Iran ; Oceans and Seas ; *Pest Control, Biological ; Population Dynamics ; *Zooplankton
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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  • 23
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    Endangered species. Ban on Beluga caviar points to sturgeon's worldwide decline (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-10-08
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pala, Christopher -- New York, N.Y. -- Science. 2005 Oct 7;310(5745):37.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16210510" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Commerce/*legislation & jurisprudence ; Conservation of Natural Resources/*legislation & jurisprudence ; *Eggs ; Fisheries ; *Fishes ; Internationality ; United States
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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    Living laboratory in peril (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-05-14
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Boersma, P Dee -- Vargas, Hernan -- Merlen, Godfrey -- New York, N.Y. -- Science. 2005 May 13;308(5724):925.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15890846" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biodiversity ; Biological Evolution ; *Conservation of Natural Resources/legislation & jurisprudence ; *Ecosystem ; Ecuador ; Emigration and Immigration/legislation & jurisprudence ; Fisheries ; Humans ; *Population Growth ; Travel
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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    Climate change and distribution shifts in marine fishes (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-05-14
    Description: We show that the distributions of both exploited and nonexploited North Sea fishes have responded markedly to recent increases in sea temperature, with nearly two-thirds of species shifting in mean latitude or depth or both over 25 years. For species with northerly or southerly range margins in the North Sea, half have shown boundary shifts with warming, and all but one shifted northward. Species with shifting distributions have faster life cycles and smaller body sizes than nonshifting species. Further temperature rises are likely to have profound impacts on commercial fisheries through continued shifts in distribution and alterations in community interactions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Perry, Allison L -- Low, Paula J -- Ellis, Jim R -- Reynolds, John D -- New York, N.Y. -- Science. 2005 Jun 24;308(5730):1912-5. Epub 2005 May 12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK. a.perry@uea.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15890845" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Body Size ; *Climate ; *Ecosystem ; Environment ; Fisheries ; *Fishes/anatomy & histology/growth & development ; North Sea ; Population Density ; Population Dynamics ; *Seawater ; Temperature ; Time Factors
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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    Reassessing U.S. coral reefs (2005)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2005-06-18
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Grigg, Richard W -- Dollar, Steven J -- New York, N.Y. -- Science. 2005 Jun 17;308(5729):1740-2; author reply 1740-2.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15961652" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Anthozoa ; *Conservation of Natural Resources ; *Ecosystem ; Eukaryota ; Fisheries ; Hawaii ; Population Dynamics ; Seals, Earless ; Turtles ; Water Pollution
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
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    HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: HEALPix the Hierarchical Equal Area isoLatitude Pixelization is a versatile structure for the pixelization of data on the sphere. An associated library of computational algorithms and visualization software supports fast scientific applications executable directly on discretized spherical maps generated from very large volumes of astronomical data. Originally developed to address the data processing and analysis needs of the present generation of cosmic microwave background experiments (e.g., BOOMERANG, WMAP), HEALPix can be expanded to meet many of the profound challenges that will arise in confrontation with the observational output of future missions and experiments, including, e.g., Planck, Herschel, SAFIR, and the Beyond Einstein inflation probe. In this paper we consider the requirements and implementation constraints on a framework that simultaneously enables an efficient discretization with associated hierarchical indexation and fast analysis/synthesis of functions defined on the sphere. We demonstrate how these are explicitly satisfied by HEALPix.
    Keywords: Astrophysics
    Type: The Astrophysical Journal; Volume 622; Issue 2; 759-771
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    The dusty AGB star RS CrB: first mid-infrared interferometric observations with the Keck telescopes (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: We report interferometric observations of the semiregular variable star RS CrB, a red giant with strong silicate emission features. The data were among the first long-baseline mid-infrared stellar fringes obtained between the Keck telescopes, using parts of the new nulling beam combiner.
    Keywords: Astrophysics
    Type: The Astrophysical Journal; Volume 634; L169-L172.
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    The electron excited ultraviolet spectrum of HD : cross sections and transition probabilities (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: We have analyzed the high-resolution ultraviolet (UV) emission spectrum of molecular deuterium hydride (HD) excited by electron impact at 100 eV under optically thin, single-scattering experimental conditions. The high-resolution spectrum (FWHM=160 mA) spans the wavelength range from 900 to 1650 A and contains the two Rydberg series of HD: (sup 1)Sigma(sub u)(sup +)1s(sigma), np(si n=2, 3, 4) --〉 X(sup 1)Sigma(sub g)(sup +) and (sup 1)Pi(sub u)(sup +)1s(sigma), np(pi)(C,D,D',D'', n=2, 3, 4, 5) --〉X(sup 1)Sigma(sub g)(sup +). A model spectrum of HD, based on newly calculated tra rovibrational coupling for the strongest band systems, B (sup 1)Sigma(sub u)(sup +)-X(sup 1)Sigma(sub g)(sup +),B'(sup 1)Sigma(sub g)(sup +)-X(sup 1)Sigma(sub g)(sup +),C(sup 1)Pi(sub u)-X(sup 1)Sigm sections for direct excitation at 100 eV of the B (sup 1)Sigma(sub u)(sup +), B' (sup 1)Sigma(sub u)(sup +), C(sup 1)Pi(sub u), and D(sup 1)Pi(sub u) states were derived from a model analysis of the state. The absolute cross section values for excitation to the B (sup 1)Sigma(sub u)(sup +), B' (sup 1)Sigma(sub u)(sup +), C(sup 1)Pi(sub u), and D(sup 1)Pi(sub u) states were found to be (2.57+/-0. and (0.17+/-0.04)x10(exp -17) sq cm, respectively. We have also determined the dissociative excitation cross sections at 100 eV for the emission of Ly(alpha) at 1216 A and Ly(Beta) at 1025 A lines, which are (7.98+/-1.12)x10(exp -18) and (0.40+/-0.10)x10(exp -18) sq cm, respectively. The summed excitation function of the closely spaced pair of lines, H Ly(alpha) and D Ly(Beta), resulting from excitation of HD, has been measured from the threshold to 800 eV and is analytically modeled with a semiempirical relation. The model cross sections are in good agreement with the corrected Ly(alpha) cross sections of Mohlmann et al. up to 2 keV. Based on measurements of H, D (2s) production cross section values by Mohlmann et al., the H, D (n=2) cross section is estimated to be 1.6 x 10(exp -17) sq cm at 100 eV.
    Keywords: Astrophysics
    Type: The Astrophysical Journal Supplement Series; Volume 159; 314-330
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    Low-order aberration sensitivity of eighth-order coronagraph masks (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: In a recent paper, Kuchner, Crepp, and Ge describe new image-plane coronagraph mask designs that reject to eighth order the leakage of starlight caused by image motion at the mask, resulting in a substantial relaxation of image centroiding requirements compared to previous fourth-order and second-order masks. They also suggest that the new masks are effective at rejecting leakage caused by low-order aberrations (e.g., focus, coma, and astigmatism). In this paper, we derive the sensitivity of eighth-order masks to aberrations of any order and provide simulations of coronagraph behavior in the presence of optical aberrations.We find that the masks leak light as the fourth power of focus, astigmatism, coma, and trefoil. This has tremendous performance advantages for the Terrestrial Planet Finder Coronagraph.
    Keywords: Astrophysics
    Type: The Astrophysical Journal; Volume 628; 474-477
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    Orgin of the Marsden and Krachet groups of sunskirting comets. I. association with comet 96P / machholz and its inteplanetary complex (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: Of the three major groups of comets approaching the Sun to between 6 and 12 solar radii and discovered with the coronagraphs on board SOHO, we investigate the Marsden and Kracht groups.We call these comets ''sunskirters'' to distinguish them from the Kreutz system sungrazers. Our objective is to understand the origin, history, and orbital evolution of the two groups.
    Keywords: Astrophysics
    Type: The Astrophysical Journal Supplement Series; Volume 161; 551-586
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    Astrometric discovery of GJ 802b : in the Brown Dwarf Oasis? (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: The Stellar Planet Survey is an ongoing astrometric search for giant planets and brown dwarfs around a sample of ~30 M dwarfs. We have discovered several low-mass companions by measuring the motion of our target stars relative to their reference frames. The lowest mass discovery thus far is GJ 802b, a companion to the M5 dwarf GJ 802A. The orbital period is 3.14 +/-0:03 yr, the system mass is 0:214 +/- 0:045 M(circled dot operator), and the semimajor axis is 1:28+/- 0:10 AU or 81 + 6 mas. Imaging observations indicate that GJ 802b is likely to be a brow with the astrometrically determined mass 0:058 +/- 0:021 M(circled dot operator) (1 (sigma) limits). The remaining uncertainty in the orbit is the eccentricity that is now loosely constrained. We dis the system age limits the mass and the prospects of further narrowing the mass range when e is more precisely determined.
    Keywords: Astrophysics
    Type: The Astrophysical Journal
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    Discovery of a Transition to Global Spin-up in EXO 2030+375 (2005)
    In:  Other Sources
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    Publication Date: 2018-06-12
    Description: EXO 2030+375, a 42 s transient X-ray pulsar with a Be star companion, has been observed to undergo an outburst at nearly every periastron passage for the last 13.5 years. From 1994 through 2002, the global trend in the pulsar spin frequency was spin-down. Using Rossi X-Ray Timing Explorer (RXTE) data from 2003 September, we have observed a transition to global spin-up in EXO 2030+375. Although the spin-frequency observations are sparse, the relative spin-up between 2002 June and 2003 September observations, along with an overall brightening of the outbursts since mid-2002 observed with the RXTE All-Sky Monitor, accompanied by an increase in density of the Be disk, indicated by infrared magnitudes, suggest that the pattern observed with BATSE of a roughly constant spin frequency, followed by spin-up, followed by spin-down is repeating. If so, this pattern has approximately an 11 yr period, similar to the 15 +/- 3 yr period derived by Wilson et al. for the precession period of a one-armed oscillation in the Be disk. If this pattern is indeed repeating, we predict a transition from spin-up to spin-down in 2005.
    Keywords: Astrophysics
    Type: Astrophysical Journal; Volume 620; No. 2; L99-L102
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    Surface charging and x-ray emission from insulator surfaces induced by collisions with highly charged ions : relevance to cometary and planetary sp (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: Characteristic X-ray emission lines are detected from simulants of comet surfaces as they undergo collisions with highly charged ions (HCIs). The HCI projectiles are O+2-O+7. Ion energies are varied in the range (2-7)q keV, where q is the ion charge state. The targets are the insulator minerals olivine, augite, and quartz. It is found that the emission of characteristic K-L, K-M X-rays appears to proceed during positive charging of the surface by the HCI beam. When one uses low-energy, flood-gun electrons to neutralize the surface charge, the X-ray emission is eliminated or greatly reduced, depending on the flood-gun current. Acceleration of background electrons onto the charged surface results in excitation of elemental transitions, including the K-L2 and K-L3 target X-ray emission lines of Mg and Si located spectroscopically at 1253.6 and 1739.4 eV, respectively. Also observed are emission lines from O, Na, Ca, Al, and Fe atoms in the target and charge-exchange lines via surface extraction of electrons by the O+q electric field. Good agreement is found in the ratio of the measured X-ray yields for Mg and Si relative to the ratio of their electron-impact K-shell ionization cross sections. The present study may serve as a guide to astronomers as to specific observing X-ray energies indicative of solar/stellar wind or magnetospheric ion interactions with a comet, planetary surface, or circumstellar dust.
    Keywords: Astrophysics
    Type: The Astrophysical Journal
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    Measurement of absolute cross sections for excitation of the 2s(2) S-1 -〉 2s2p P-1 degrees transition in O+4 (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: Experimental cross sections are reported for the 1s(2)2s(2) S-1 -〉 1s(2)2s2p P-1(o) transition in O+4 located at 19.689 eV. Use is made of the electron energy-loss method, using a merged electron-ion beam geometry. The center-of-mass interaction energies for the measurements in the S-1 -〉 P-1(o) transition are in the range 18 eV ( below the threshold) to 30 eV. Data are compared with other previous electron energy-loss measurements and with results of a 26 term R-matrix calculation that includes fine structure explicitly via the Breit-Pauli Hamiltonian. Clear resonance enhancement is observed in all experimental and theoretical results near the threshold for this S-1 -〉 P-1(o) transition.
    Keywords: Astrophysics
    Type: The Astrophysical Journal
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    Discovery of a Neutron Star with Spin Frequency 530 Hz in A1744-361 (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: We report the detection with the Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA) of 530 Hz burst oscillations in a thermonuclear (Type I) burst from the transient X-ray source A1744-361. This is only the second burst ever observed from this source, and the first to be seen in any detail. Our results confirm that A1744-361 is a low mass X-ray binary (LMXB) system harboring a rapidly rotating neutron star. The oscillations are first detected along the rising edge of the burst, and show evidence for frequency evolution of a magnitude similar to that seen in other burst sources. The modulation amplitude and its increase with photon energy are also typical of burst oscillations. The lack of any strong indication of photospheric radius expansion during the burst suggests a 9 kpc upper limit of the source distance. We also find energy dependent dips, establishing A1744-361 as a high inclination, dipping LMXB. The timescale between the two episodes of observed dips suggests an orbital period of approx. 97 min. We have also detected a 2 - 4 Hz quasi-periodic-oscillation (QPO) for the first time from this source. This QPO appears consistent with approx. 1 Hz QPOs seen from other high inclination systems. We searched for kilohertz QPOs, and found a suggestive 2.3 sigma feature at 800 Hz in one observation. The frequency, strength and quality factor are consistent with that of a lower frequency kilohertz QPO, but the relatively low significance argues for caution, so we consider this a tentative detection requiring confirmation.
    Keywords: Astrophysics
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    Post-Launch Analysis of Swift's Gamma-Ray Burst Detection Sensitivity (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: The dependence of Swift#s detection sensitivity on a burst#s temporal and spectral properties shapes the detected burst population. Using s implified models of the detector hardware and the burst trigger syste m I find that Swift is more sensitive to long, soft bursts than CGRO# s BATSE, a reference mission because of its large burst database. Thu s Swift has increased sensitivity in the parameter space region into which time dilation and spectral redshifting shift high redshift burs ts.
    Keywords: Astrophysics
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    Sonoluminescence: A Galaxy of Nanostars Created in a Beaker (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-02
    Description: As part of basic and applied research on advanced instrumentation technologies, the NASA Glenn Research Center is examining applications for sonoluminescence: ultrasonically produced glowing bubbles that are hotter than the Sun. In the last decade, those outside of the ultrasonic community have become interested in understanding sonoluminescence and in using some of its more interesting properties. First discovered in the 1930s as a byproduct of early work on sonar, the phenomenon is defined as the generation of light energy from sound waves. This glow, which was originally thought to be a form of static electricity, was found to be generated in flashes of much less than a billionth of a second that result when microscopic bubbles of air collapse. The temperature generated in the collapsing bubbles is at least 4 times that of the surface of the Sun.
    Keywords: Astrophysics
    Type: Research and Technology 2004; NASA/TM-2005-213419
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    GRAVITATIONAL WAVE EXTRACTION FROM AN INSPIRALING CONFIGURATION OF MERGING BLACK HOLES (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: We present new techniques for evolving binary black hole systems which allow the accurate determination of gravitational waveforms directly from the wave zone region of the numerical simulations. Rather than excising the black hole interiors, our approach follows the "puncture" treatment of black holes, but utilizing a new gauge condition which allows the black holes to move successfully through the computational domain. We apply these techniques to an inspiraling binary, modeling the radiation generated during the final plunge and ringdown. We demonstrate convergence of the waveforms and and good conservation of mass-energy, with just over 3% of the system s mass converted to gravitational radiation.
    Keywords: Astrophysics
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    Protostars are Nature's Chemical Factories (2005)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: H(2-2), N2 and CO are the most abundant molecular constituents in astrophysical environments, including protostellar nebulae. Although some organic molecules may be produced on very long timescales by the irradiation of ices formed on the cold surfaces of interstellar grains and these molecules may be an important source of raw materials leading to the origin of life on Earth, pre-solar organics could be swamped by the efficient conversion of nebular H2, N2 and CO to simple organic materials.
    Keywords: Astrophysics
    Type: Lunar and Planetary Science XXXVI, Part 14; LPI-Contrib-1234-Pt-14
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    Topography of the 81/P Wild 2 Nucleus Derived from Stardust Stereoimages (2005)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: On 2 January, 2004, the Stardust spacecraft flew by the nucleus of comet 81P/Wild 2 with a closest approach distance of approx. 240 km. During the encounter, the Stardust Optical Navigation Camera (ONC) obtained 72 images of the nucleus with exposure times alternating between 10 ms (near-optimal for most of the nucleus surface) and 100 ms (used for navigation, and revealing additional details in the coma and dark portions of the surface. Phase angles varied from 72 deg. to near zero to 103 deg. during the encounter, allowing the entire sunlit portion of the surface to be imaged. As many as 20 of the images near closest approach are of sufficiently high resolution to be used in mapping the nucleus surface; of these, two pairs of short-exposure images were used to create the nucleus shape model and derived products reported here. The best image resolution obtained was approx. 14 m/pixel, resulting in approx. 300 pixels across the nucleus. The Stardust Wild 2 dataset is therefore markedly superior from a stereomapping perspective to the Deep Space 1 MICAS images of comet Borrelly. The key subset of the latter (3 images) covered only about a quarter of the surface at phase angles approx. 50 - 60 and less than 50 x 160 pixels across the nucleus, yet it sufficed for groups at the USGS and DLR to produce digital elevation models (DEMs) and study the morphology and photometry of the nucleus in detail.
    Keywords: Astrophysics
    Type: Lunar and Planetary Science XXXVI, Part 11; LPI-Contrib-1234-Pt-11
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    X-rays from Cepheus A East and West (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: We report the discovery of X-rays from both components of Cepheus A, East and West, with the XMM-Newton observatory. HH 168 joins the ranks of other energetic Herbig-Haro objects that are sources of T ≥ 10(6) K X-ray emission. The effective temperature of HH 168 is T = 5.8(-2.3)(+3.5) x 10(6) K, and its unabsorbed luminosity is 1: 1; 10(29) ergs s(-1), making it hotter and less luminous than other representatives of its class. We also detect prominent X-ray emission from the complex of compact radio sources believed to be the power sources for Cep A. We call this source HWX, and it is distinguished by its hard X-ray spectrum, T = 1.2(-0.5)(+1.2) 10(8) K, and its complex spatial distribution. It may arise from one or more protostars associated with the radio complex, the outflows, or a combination of the two. We detect 102 X-ray sources, many presumed to be pre-main-sequence stars on the basis of the reddening of their optical and IR counterparts.
    Keywords: Astrophysics
    Type: The Astrophysical Journal
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    Line asymmetry in the Seyfert Galaxy NGC 3783 (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: We have reanalyzed the 900 ks Chandra X-ray spectrum of NGC 3783, finding evidence on the asymmetry of the spectral absorption lines. The lines are fitted with a parametric expression that results from an analytical treatment of radiatively driven winds. The line asymmetry distribution derived from the spectrum is consistent with a non-spherical outflow with a finite optical depth. Within this scenario, our model explains the observed correlations between the line velocity shifts and the ionization parameter and between the line velocity shift and the line asymmetry. The present results may provide a framework for detailed testing of models for the dynamic and physical properties of warm absorber in Seyfert galaxies.
    Keywords: Astrophysics
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    Impact of LISA's Low Frequency Sensitivity on Observations of Massive Black Hole Mergers (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: LISA will be able to detect gravitational waves from inspiralling massive black hole (MBH) binaries out to redshifts z 〉 10. If the binary masses and luminosity distances can be extracted from the Laser Interferometer Space Antenna (LISA) data stream, this information can be used to reveal the merger history of MBH binaries and their host galaxies in the evolving universe. Since this parameter extraction generally requires that LISA observe the inspiral for a significant fraction of its yearly orbit, carrying out this program requires adequate sensitivity at low frequencies, f 〈 10(exp -4) Hz. Using several candidate low frequency sensitivities, we examine LISA's potential for characterizing MBH binary coalescences at redshifts z 〉 1.
    Keywords: Astrophysics
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    Testing the Gamma-Ray Burst Energy Relationships (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: Building on Nakar & Piran's analysis of the Amati relation relating gamma-ray burst peak energies E(sub p) and isotropic energies E(sub iso ) we test the consistency of a large sample of BATSE bursts with the Amati and Ghirlanda (which relates peak energies and actual gamma-ray energies E(sub gamma)) relations. Each of these relations can be exp ressed as a ratio of the different energies that is a function of red shift (for both the Amati and Ghirlanda relations) and beaming fraction f(sub B) (for the Ghirlanda relation). The most rigorous test, whic h allows bursts to be at any redshift, corroborates Nakar & Piran's r esult - 88% of the BATSE bursts are inconsistent with the Amati relat ion - while only l.6% of the bursts are inconsistent with the Ghirlan da relation if f(sub B) = 1. Modelling the redshift distribution resu lts in an energy ratio distribution for the Amati relation that is sh ifted by an order of magnitude relative to the observed distributions; any sub-population satisfying the Amati relation can comprise at mos t approx. 18% of our burst sample. A similar analysis of the Ghirland a relation depends sensitively on the beaming fraction distribution f or small values of f(sub B); for reasonable estimates of this distrib ution about a third of the burst sample is inconsistent with the Ghir landa relation. Our results indicate that these relations are an artifact of the selection effects of the burst sample in which they were f ound; these selection effects may favor sub-populations for which the se relations are valid.
    Keywords: Astrophysics
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    The Highest-Energy Photons Seen by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: During its nine-year lifetime, the Energetic Gamma Ray Experiment Telescope (EGBET) on the Compton Gamma Ray Observatory (CGRO) detected 1506 cosmic photons with measured energy E〉10 GeV. Of this number, 187 are found within a 1 deg of sources that are listed in the Third EGRET Catalog and were included in determining the detection likelihood, flux, and spectra of those sources. In particular, five detected EGRET pulsars are found to have events above 10 GeV, and together they account for 37 events. A pulsar not included in the Third EGRET Catalog has 2 events, both with the same phase and in one peak of the lower-energy gamma-ray light-curve. Most of the remaining 1319 events appear to be diffuse Galactic and extragalactic radiation based on the similarity of the their spatial and energy distributions with the diffuse model and in the E〉100, MeV emission. No significant time clustering which would suggest a burst was detected.
    Keywords: Astrophysics
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    Millisecond X-ray Pulses from Cygnus X-1 (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: X-ray pulses with millisecond-long FWHM have been detected in RXTE (Rossi X-Ray Timing Explorer) satellite observations of Cyg X-1. Their identity as short- timescale variations in the X-ray luminosity of the source, and not stochastic variability in the X-ray flux, is established by their simultaneous occurrence and similar pulse structure in two independent energy bandpasses. The light-time distance corresponding to the timescale of their FWHM indicates that they originate in the inner region of the accretion disk around the system's black hole component. The fluence in the pulses can equal or exceed the fluence of the system's average continuous flux over the duration of the pulse's FWHM in several different bandpasses between 1 and 73 keV. Millisecond pulses are detected during both high and low luminosity states of Cyg X-1, and during transitions between luminosity states.
    Keywords: Astrophysics
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    Cosmic Infrared Background and Early Stellar Populations (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: Cosmic infrared background (CIB) contains information about galaxy luminosities over the entire history of the Universe and can be a powerful diagnostic of the early populations otherwise inaccessible to telescopic studies. Its measurements are very difficult because of the strong IR foregrounds from the Solar system and the Galaxy. Nevertheless, substantial recent progress in measuring the CIB and its structure has been made. The measurements now allow to set significant constraints on early galaxy evolution and, perhaps, even detect the elusive Population III era. We discuss briefly the theory behind the CIB, review the latest measurements of the CIB and its structure, and discuss their implications for detecting and/or constraining the first stars and their epochs.
    Keywords: Astrophysics
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    NASA Strategic Roadmap: Origin, Evolution, Structure, and Destiny of the Universe (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: The NASA strategic roadmap on the Origin, Evolution, Structure and Destiny of the Universe is one of 13 roadmaps that outline NASA s approach to implement the vision for space exploration. The roadmap outlines a program to address the questions: What powered the Big Bang? What happens close to a Black Hole? What is Dark Energy? How did the infant universe grow into the galaxies, stars and planets, and set the stage for life? The roadmap builds upon the currently operating and successful missions such as HST, Chandra and Spitzer. The program contains two elements, Beyond Einstein and Pathways to Life, performed in three phases (2005-2015, 2015-2025 and 〉2025) with priorities set by inputs received from reviews undertaken by the National Academy of Sciences and technology readiness. The program includes the following missions: 2005-2015 GLAST, JWST and LISA; 2015-2025 Constellation-X and a series of Einstein Probes; and 〉2025 a number of ambitious vision missions which will be prioritized by results from the previous two phases.
    Keywords: Astrophysics
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    Analysis of variability in the burst oscillations of the accreting millisecond pulsar XTE J1814-338 (2005)
    In:  CASI
    Details
    Publication Date: 2018-06-06
    Description: The accreting millisecond pulsar XTE J1814-338 exhibits oscillations at the known spin frequency during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. We present an analysis of the variability of the burst oscillations of this source, focusing on three characteristics: fractional amplitude, harmonic content and frequency. Fractional amplitude and harmonic content constrain the size, shape and position of the emitting region, whilst variations in frequency indicate motion of the emitting region on the neutron star surface. We examine both long-term variability over the course of the outburst, and short-term variability during the bursts. For most of the bursts, fractional amplitude is consistent with that of the accretion pulsations, implying a low degree of fuel spread. There is however a population of bursts whose fractional amplitudes are substantially lower, implying a higher degree of fuel spread, possibly forced by the explosive burning front of a precursor burst. For the first harmonic, substantial differences between the burst and accretion pulsations suggest that hotspot geometry is not the only mechanism giving rise to harmonic content in the latter. Fractional amplitude variability during the bursts is low; we can only rule out the hypothesis that the fractional amplitude remains constant at the l(sigma) level for bursts that do not exhibit photospheric radius expansion (PRE). There are no significant variations in frequency in any of the bursts except for the one burst that exhibits PRE. This burst exhibits a highly significant but small (= 0.1Hz) drop in frequency in the burst rise. The timescale of the frequency shift is slower than simple burning layer expansion models predict, suggesting that other mechanisms may be at work.
    Keywords: Astrophysics
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  • 51
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    Gamma-Ray Spectral State Transitions of GRO J1719-24 (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: We report the results of an in-depth study of the long-term soft gamma-ray (30 keV to 1.7 MeV) flux and spectral variability of the transient source GRO J1719-24 that was first discovered by BATSE and SIGMA in the fall of 1993. Our results were obtained from the JPL BATSE-EBOP database covering a 1000 day period between 1993 January 13 and 1995 October 10. During this period, the source underwent a major outburst in the fall of 1993 when the 35-100 keV flux rose from a quiescent state of less than 16 mcrab before 1993 September 17 to a level of 1.5 crab on October 3. The source remained in this high-intensity state over the next approx. 70 days, during which the 35-100 keV flux decreased monotonically by 33% to 1 crab on December 12, then decreased sharply to the pretransition quiescent level of 44 mcrab on December 21, where it remained until 1994 September 5. During a 400 day period between 1994 September 5 and 1995 October 10, the source again underwent a series of five transitions when the 35-100 keV flux increased to low-intensity levels of 200 400 mcrab, a factor of 4-7 times lower than what was observed in 1993. The low- and high-intensity states were characterized by two different spectral shapes. The low-state spectra are described by a power law with a spectral index of approx. 2. The high-state spectra, on the other hand, have two components: a thermal Comptonized shape below approx. 200 keV with electron temperature k(sub Te) of approx. 37 keV and optical depth tau approx. 2.8, and a soft power-law tail with photon index of 3.4 above 200 keV that extends to approx. 500 keV. The softer high-intensity spectrum and the harder low-intensity spectrum intersect at approx. 400 keV. The nonthermal power-law gamma-ray component in both the high- and low-intensity spectra suggests that the persistent nonthermal emission source is coupled to the hot and variable thermal emission source in the system. Furthermore, the correlation of the spectral characteristics with the high- and low-intensity states resembles that seen in two other gamma-ray emitting black hole candidates, GRO J0422+32 and Cygnus X-1, suggesting that perhaps similar system configurations and processes are occurring in these systems. Possible scenarios for interpreting these behaviors are discussed.
    Keywords: Astrophysics
    Type: The Astrophysical Journal; Volume 622; 492-502
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    Warm Molecular Gas Traced with CO J = 7 --〉 6 in the Galaxy's Central 2 Parsecs: Dynamical Heating of the Circumnuclear Disks (2005)
    In:  Other Sources
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    Publication Date: 2018-06-11
    Description: We present an 11" resolution map of the central 2 pc of the Galaxy in the CO J = 7 --〉 6 rotational transition. The CO emission shows rotation about Sgr A* but also evidence for noncircular turbulent motion and a clumpy morphology. We combine our data set with available CO measurements to model the physical conditions in the disk. We find that the molecular gas in the region is both warm and dense, with T approx. 200-300 K and n(sub H2) approx. (5-7) x 10(exp 4) cm(exp -3). The mass of warm molecular gas we measure in the central 2 pc is at least 2000 M(solar), about 20 times the UV-excited atomic gas mass, ruling out a UV heating scenario for the molecular material. We compare the available spectral tracers with theoretical models and conclude that molecular gas is heated with magnetohydrodynamic shocks with v approx. 10-20 km s(exp -1) and B approx. 0.3- 0.5 mG. Using the conditions derived with the CO analysis, we include the other important coolants, neutral oxygen and molecular hydrogen, to estimate the total cooling budget of the molecular material. We derive a mass-to-luminosity ratio of approx. 2-3 M(solar)(L(solar)exp -1), which is consistent with the total power dissipated via turbulent decay in 0.1 pc cells with v(sub rms) approx. 15 kilometers per second. These size and velocity scales are comparable to the observed clumping scale and the velocity dispersion. At this rate, the material near Sgr A* is dissipating its orbital energy on an orbital timescale and cannot last for more than a few orbits. Our conclusions support a scenario in which the features near Sgr A* such as the circumnuclear disk and northern arm are generated by infalling clouds with low specific angular momentum.
    Keywords: Astrophysics
    Type: Astrophysical Journal; Volume 623; 866-876
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    Introduction to Particle Acceleration in the Cosmos (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Accelerated charged particles have been used on Earth since 1930 to explore the very essence of matter, for industrial applications, and for medical treatments. Throughout the universe nature employs a dizzying array of acceleration processes to produce particles spanning twenty orders of magnitude in energy range, while shaping our cosmic environment. Here, we introduce and review the basic physical processes causing particle acceleration, in astrophysical plasmas from geospace to the outer reaches of the cosmos. These processes are chiefly divided into four categories: adiabatic and other forms of non-stochastic acceleration, magnetic energy storage and stochastic acceleration, shock acceleration, and plasma wave and turbulent acceleration. The purpose of this introduction is to set the stage and context for the individual papers comprising this monograph.
    Keywords: Astrophysics
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    The FUV Flux Irradiating the Surfaces of Protostellar Disks (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: This grant was intended for, and has been used for, the support of the specialized CalFUSE data reduction required for these non-standard observations. The goal of the program was to search for FUV continuum radiation from T-Tauri stars, which would have affected the chemistry in the proto-planetary disk. Because of the low flux expected, the standard background subtraction method would not be appropriate. Rather on-chip background determination was expected to be required.
    Keywords: Astrophysics
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    Cosmology, Clusters and Calorimeters (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: I will review the current state of Cosmology with Clusters and discuss the application of microcalorimeter arrays to this field. With the launch of Astro-E2 this summer and a slew of new missions being developed, microcalorimeters are the next big thing in x-ray astronomy. I will cover the basics and not-so-basic concepts of microcalorimeter designs and look at the future to see where this technology will go.
    Keywords: Astrophysics
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    Observing Massive Black Hole Binary Coalescences with LISA (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Massive black hole binary coalescences are among the most important astrophysical sources of gravitational waves to be observed by LISA. The ability to observe and characterize such sources with masses approximately equal to 105 M/odot and larger at high redshifts is strongly dependent on the sensitivity of LISA in the low frequency (0.1 mHz and below) regime. We examine LISA's ability to observe these systems at redshifts up to z approximately equal to 10 for various proposed values of the low frequency sensitivity, under current assumptions about the merger rates. The discussion will focus on the astrophysical information that can be gained by these observations.
    Keywords: Astrophysics
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    The Chandra X-Ray Observatory: The Past, the Present, and the Future (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The Chandra X-ray Observatory had its origins in a 1963 proposal led by Riccardo Giacconi that called for a 1-meter diameter, 1-arcsecond class X-Ray telescope for studying the Universe. We will briefly discuss the history of the mission, the development of the hardware, its testing, and the launch on 1999, July 23. The majority of the talk will be an admittedly eclectic review of some of the most exciting scientific highlights. These include the detection and identification of the first source seen with Chandra - an unusual Seyfert 1 we nicknamed Leon X-1, the detailed study of the Crab Nebula and its pulsar, and spectacular images of other supernova remnants including the recent 1-Million second exposure on Cas A. We also will summarize some of the major Chandra findings for normal and active galaxies and we will illustrate the breadth of science enabled by Chandra observations of clusters of galaxies. We will close with a brief look towards the future of the field.
    Keywords: Astrophysics
    Type: 205th Meeting of the American Astronomical Society; Jan 09, 2005 - Jan 13, 2005; San Diego, CA; United States
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    First Light from Extrasolar Planets and Implications for Astrobiology (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The first light from an extrasolar planet was recently detected. These results, obtained for two transiting extrasolar planets at different infrared wavelengths, open a new era in the field of extrasolar planet detection and characterization because for the first time we can now detect planets beyond the solar system directly. Using the Spitzer Space Telescope at 24 microns, we observed the modulation of combined light (star plus planet) from the HD 209458 system as the planet disappeared behind the star during secondary eclipse and later re-emerged, thereby isolating the light from the planet. We obtained a planet-to-star ratio of 0.26% at 24 microns, corresponding to a brightness temperature of 1130 + / - 150 K. We will describe this result in detail, explain what it can tell us about the atmosphere of HD 209458 b, and discuss implications for the field of astrobiology. These results represent a significant step on the path to detecting terrestrial planets around other stars and in understanding their atmospheres in terms of composition and temperature.
    Keywords: Astrophysics
    Type: Astrobiology and the Origins of Life; May 24, 2005 - May 28, 2005; Hamilton, Ontario; Canada
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    Atomic Processes in X-ray Photoionized Gas (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: It has long been known that photoionization and photoabsorption play a dominant role in determining the state of gas in nebulae surrounding hot stars and in active galaxies. Recent observations of X-ray spectra demonstrate that these processes are also dominant in highly ionized gas near compact objects, and also affect the transmission of X-rays from the majority of astronomical sources. This has led to new insights into the understanding of what is going on in these sources. It has also pointed out the need for a better atomic cross sections for photoionization and absorption, notably for processes involving inner shells. In this talk I will discuss these issues, what is known and where more work is needed.
    Keywords: Astrophysics
    Type: APS/DAMOP Conference; May 18, 2005 - May 19, 2005; Lincoln, NE; United States
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    Gravitational Wave Science: Challenges for Numerical Relativistic Astrophysics (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Gravitational wave detectors on earth and in space will open up a new observational window on the universe. The new information about astrophysics and fundamental physics these observations will bring is expected to pose exciting challenges. This talk will provide an overview of this emerging area of gravitational wave science, with a focus on the challenges it will bring for numerical relativistic astrophysics and a look at some recent results.
    Keywords: Astrophysics
    Type: PCA Workshop; May 01, 2005 - May 05, 2005; CA; United States
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    Hotspot or Heatwave? Getting to Grips with Neutron Star Burst Oscillations (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Many accreting neutron stars, including two of the millisecond pulsars, exhibit high frequency oscillations during Type I X-ray bursts. The properties of the burst oscillations reflect the nature of the thermal asymmetry on the stellar surface. The mechanism that gives rise to the aspzetry, however , remains unclear: possibilities include a hotspot due to uneven fuel distribution, modes of oscillation in the surface layers of the neutron star, or vortices driven by the Coriolis force. I will review some of the latest theory and observations, and present the results of a recent study of variability in the burst oscillations of the millisecond pulsar 51814-338.
    Keywords: Astrophysics
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    The Cycle of Cosmic Dust (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The presence of dust in the interstellar medium of galaxies dramatically affects their spectral appearance, and the interpretation of their underlying physical properties. Consequently, the diagnostic of galaxy spectra depends crucially on our understanding of the nature and properties of these dust particles. Models of interstellar dust particles must be able to reproduce a basic set of observational constraints, including the general interstellar extinction and infrared emission observed in the diffuse interstellar medium (ISM). Recent analysis of the solar spectrum have resulted in a convergence between the solar and B star abundances. This development, and the steadiness in the solar abundance determination of the primary refractory elements Mg, Si, and Fe, strongly suggest that any viable dust model must also obey interstellar abundances constraints. I will present fifteen dust models that differ in composition and size distribution and that simultaneously satisfy the local extinction, infrared emission, and abundances constraints have been shown to exist. This multitude of viable dust models provides us with an increased flexibility in understanding dust evolution and the many variations in dust properties in different phases of the ISM and stellar environments.
    Keywords: Astrophysics
    Type: International Conference on Planetary Nebulae as Astronomical Tool; Jun 26, 2005 - Jul 02, 2005; Gdansk; Poland
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    Observations of Compact X-Ray Binaries with Chandra (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: We review the the past five years of observations of compact X-ray binaries with NASA's chandra X-Ray Observatory.
    Keywords: Astrophysics
    Type: Spectra and Timing of Compact X-Ray Binaries; Jan 17, 2005 - Jan 21, 2005; Mumbai; India
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    Proceedings of Protostars and Planets V (2005)
    In:  Other Sources
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    Publication Date: 2019-07-13
    Description: Oral presentation sessions in this conference include: Clouds and cores; Star formation and protostars; Binaries and multiples; Newborn massive stars; jets and outflows; Clusters and associations; T Tauri stars and disks; Brown dwarfs; Planet formation and evolution; Extrasolar planets; Dust and protoplanetary disks; Early solar system and Astrobiology. Poster presentations included: Clouds and Cores. Collapse and Protostars, Binaries and Multiples, Clusters, Associations, and the IMF, Jets and Outflows, T Tauri Stars and Other Young Stars, Disks and Disk Accretion, Brown Dwarfs, Herbig Ae/Be Stars and Massive Stars, Solar System Objects, Planet Formation, Extrasolar Planets and Planet Detection, Properties of Protoplanetary Disks, Migration and Planetary Orbits and Meteoritics and Astrobiology
    Keywords: Astrophysics
    Type: LPI-Contrib-1286 , Protostars and Planets V; Oct 24, 2005 - Oct 28, 2005; Waikoloa Village, HI; United States|(ISSN 1540-7845)
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    The Extreme Spin of the Black Hole in Cygnus X-1 (2005)
    In:  CASI
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    Publication Date: 2019-07-19
    Description: The compact primary in the X-ray binary Cygnus X-1 was the first black hole to be established via dynamical observatIOns. We have recently determined accurate values for its mass and distance, and for the orbital inclination angle of the binary. Building on these.results, which are based on our favored (asynchronous) dynamical model, we have measured the radius of the inner edge of the black hole's accretion disk by fitting its thermal continuum.spectrum to a fully relativistic model of a thin accretion disk. Assuming that the spin axis of the black hole is aligned with the orbital angular momentum vector, we have determined that Cygnus X-I contains a near-extreme Kerr black hole with a spin parameter a* 〉 0.95 (3(sigma)). For a less probable (synchronous) dynamIcal model, we find a* 〉 0.92 (3(sigma)). In our analysis, we include the uncertainties in black hole mass orbital inclination angle and distance, and we also include the uncertainty in the calibration of the absolute flux via the Crab. These four sources of uncertainty totally dominate the error budget. The uncertainties introduced by the thin-disk model we employ are particularly small in this case given the extreme spin of the black hole and the disk's low luminosity.
    Keywords: Astrophysics
    Type: GSFC.JA.5551.2011
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    Near Infrared Spectra of Mixtures Relevant to Icy Satellites (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: We will present near IR spectra of ice mixtures and review the differences between spectra of mixtures and those of pure solids: the creation of new features, weakening and shifting of bands, dependence on concentration, and changes with temperature. The forbidden CO2 (2nu3) overtone at 2.134 microns (4685/cm) is absent from the spectrum of pure CO2, but present in all of the following mixtures: H2O/CO2 = 5 and = 25, H2O:CH3OH:CO2 = 100:2.5:1, and CH3OH:CO2 = 5. Also, in mixtures of H2O and any other material, we see a feature at 1.89 microns (5290/cm) that is possibly related to the "dangling OH" feature at 2.73 microns (3360/cm). The features of a material in H2O are generally weaker and shifted to longer wavelength in comparison to the pure substance. For example, the largest near-IR absorption of pure solid CH4 is located at 2.324 microns (4303/cm) but is broader and at slightly longer wavelength in samples mixed with H2O. The degree of shifting and weakening depends on the ratio of the mixture. The mixture mentioned above was at a ratio of H2O/ CH4 = 3. When the ratio rises to H2O/ CH4 = 87, the CH4 feature at 2.324 microns is shifted to shorter wavelength and is much broader and weaker. In CH4/ H2O mixtures the peaks shift to higher frequency and become increasingly broad, but this trend is reversible on re-cooling, even though the phase transitions of H2O are irreversible. In short, mixtures created in the lab produce spectra that are very different from modeled combinations of end member species. Recent Cassini VIMS observations show the CO2 fundamental at 4.255 microns (2350/cm) on Iapetus [l] and at 4.26 microns (2347/cm) on Phoebe [2], while Galileo NIMS observed it at 4.25 microns (2353/cm) on Ganymede [3]. Since pure CO2 is located at 4.266 (2344/cm), the CO2 must be mixed with something else to produce the shift. A mixture of CH3OH:CO2 = 5 at 90 K shifts the fundamental to 4.262 microns (2346/cm). The shifts in the feature between satellites could indicate variations in concentration and temperature, or the introduction of a new compound, encouraging further lab investigation.
    Keywords: Astrophysics
    Type: American Geophysical Union Conference; Dec 05, 2005 - Dec 09, 2005; San Francisco, CA; United States
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    Deconvolution of Energy Spectra in the ATIC Experiment (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The Advanced Thin Ionization Calorimeter (ATIC) balloon-borne experiment is designed to perform cosmic- ray elemental spectra measurements from below 100 GeV up to tens TeV for nuclei from hydrogen to iron. The instrument is composed of a silicon matrix detector followed by a carbon target, interleaved with scintillator tracking layers, and a segmented BGO calorimeter composed of 320 individual crystals totalling 18 radiation lengths, used to determine the particle energy. The technique for deconvolution of the energy spectra measured in the thin calorimeter is based on detailed simulations of the response of the ATIC instrument to different cosmic ray nuclei over a wide energy range. The method of deconvolution is described and energy spectrum of carbon obtained by this technique is presented.
    Keywords: Astrophysics
    Type: 29th International Cosmic Ray Conference; Aug 03, 2005 - Aug 10, 2005; Pune; India
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    Search for Polarization from the Prompt Gamma-Ray Emission of GRB 041219 with SPI on INTEGRAL (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Measuring the polarization of the prompt gamma-ray emission from GRBs can significantly improve our understanding of both the GRB emission mechanisms, as well as the underlying engine driving the explosion. We searched for polarization in the prompt gamma-ray emission of GRB 041219 with the SPI instrument on INTEGRAL. Using multiple-detector coincidence events in the 100-500 keV energy band, our analysis yields a polarization fraction from this GRB of 66 f 21%. While statistically this measurement suggests a non-zero polarization, we cannot strongly rule out the possibility that the measured modulation is dominated by instrumental systematics. Therefore, SPI observations of GRB 041219 do not significantly constrain GRB models. However, this measurement demonstrates the capability of SPI to measure polarization, and the techniques developed for this analysis.
    Keywords: Astrophysics
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    Coherence Effects in Ring Laser Gyros (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: We predict the propagation of slow and fast light in two co-resonant coupled optical resonators. In coupled resonators, slow light can propagate without attenuation by a cancellation of absorption as a result of mode splitting and destructive interference, whereas transparent fast light propagation can be achieved by the assistance of gain and splitting of the intracavity resonances, which consequently change the dispersion from normal to anomalous. The effective steady-state response of coupled- resonators is derived using the temporal coupled-mode formalism, and the absorptive and dispersive responses are described. Specifically, the occurrence of slow light via coupled-resonator-induced transparency and gain-assisted fast light are discussed. Keywords: whispering gallery modes, optical resonators, slow light, fast light, superluminal pulse propagation, coupled optical resonators.
    Keywords: Astrophysics
    Type: International Society for Optical Engineering Optics and Photonics Conference; Jul 31, 2005 - Aug 04, 2005; San Diego, CA; United States
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    X-Ray Probes of Jupiter's Auroral Zones, Galilean Moons, and the Io Plasma Torus (2005)
    In:  Other Sources
    Details
    Publication Date: 2019-07-18
    Description: Remote observations from the Earth orbiting Chandra X-ray Observatory and the XMM-Newton Observatory have shown the the Jovian system is a rich and complex source of x-ray emission. The planet's auroral zones and its disk are powerful sources of x-ray emission, though with different origins. Chandra observations discovered x-ray emission from the Io plasma torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from the moons is due to bombardment of their surfaces by highly energetic magnetospheric protons, and oxygen and sulfur ions, producing fluorescent x-ray emission lines from the elements in their surfaces against an intense background continuum. Although very faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around the icy Galilean moons would provide a detail mapping of the elemental composition in their surfaces. Here we review the results of Chandra and XMM-Newton observations of the Jovian system and describe the characteristics of X-MIME, an imaging x-ray spectrometer undergoing study for possible application to future missions to Jupiter such as JIMO. X-MIME has the ultimate goal of providing detailed high-resolution maps of the elemental abundances of the surfaces of Jupiter's icy moons and Io, as well as detailed study of the x-ray mission from the Io plasma torus, Jupiter's auroral zones, and the planetary disk.
    Keywords: Astrophysics
    Type: 2005 SPIE Optics and Photonics Conference; Jul 31, 2005 - Aug 04, 2005; San Diego, CA; United States
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    Modeling contamination migration on the Chandra X-Ray Observatory (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: During its first 5 years of operation, the cold (-60 C) optical blocking filter of the Advanced CCD Imaging Spectrometer (ACIS), on board the Chandra X-ray Observatory, has accumulated a contaminating layer that attenuates the low-energy x rays. To assist in assessing the likelihood of successfully baking off the contaminant, members of the Chandra Team developed contamination-migration simulation software. The simulation follows deposition onto and (temperature-dependent) vaporization from surfaces comprising a geometrical model of the Observatory. A separate thermal analysis, augmented by on-board temperature monitoring, provides temperatures for each surface of the same geometrical model. This paper describes the physical basis for the simulations, the methodologies, and the predicted migration of the contaminant for various bake-out scenarios and assumptions.
    Keywords: Astrophysics
    Type: 2005 SPIE Meeting; Jul 31, 2005 - Aug 04, 2005; San Diego, CA; United States
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    Managing radiation degradation of CCDs on the Chandra X-ray Observatory II (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The CCDs on the Chandra X-ray Observatory are vulnerable to radiation damage from low-energy protons scattered off the telescope's mirrors onto the focal plane. Following unexpected damage incurred early in the mission, the Chandra Team developed, implemented, and maintains a radiation-protection program. This program - involving scheduled radiation safing during radiation-belt passes, intervention based upon real-time space-weather conditions and radiation-environment modeling, and on-board radiation monitoring with autonomous radiation safing - has successfully managed the radiation damage to the CCDs. Since implementing the program, the charge-transfer inefficiency (CTI) has increased at an average annual rate of only 2.9x10^-6 (2.3%) for the front- illuminated CCDs and 0.95x10^-6 (6.5%) for the back-illuminated CCDs. This paper describes the current status of Chandra radiation-management program.
    Keywords: Astrophysics
    Type: 2005 SPIE Meeting; Jul 31, 2005 - Aug 04, 2005; San Diego, CA; United States
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    A Burst and Simultaneous Short-term Pulsed Flux Enhancement fom the Magnetar Candidate 1E 1048.1-5937 (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: We report on the latest X-ray burst detected from the direction of the Anomalous X-ray Pulsar (AXP) 1E 1048.1-5937 using the Rossi X-ray Timing Explorer (RXTE). Following the burst the AXP was observed further with RXTE, XMM-Newton and Chandra. We find a simultaneous increase of approx. 3.7 times the quiescent value (approx. 5 sigma) in the pulsed component of the pulsar's flux during the tail of the burst which identifies the AXP as the burst's origin. The burst was overall very similar to the two others reported from this source in 2001. The unambiguous identification of 1E 1048.1-5937 as the burster here suggests it was in 2001 as well. Pre- and post-burst observations revealed no change in the total flux or spectrum of the quiescent emission. Comparing all three bursts detected thus far from this source we find that this event was the most fluent (170+/-42 x 10(exp -10) erg cm-2), had the highest peak flux (71+/-16 x 10(exp -10) erg/s/sq cm), the longest duration (approx. 411 s). The epoch of the burst peak was consistent with the arrival time of 1E 1048.1-5937's pulse peak. The burst exhibited significant spectral evolution with the trend going from hard to soft. Although the average spectrum of the burst was comparable in hardness (Gamma approx. 1) to those of the 2001 bursts, the peak of this burst was much harder (Gamma approx. 0.5).
    Keywords: Astrophysics
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    Phototelectric Emission Measurements on the Analogs of Individual Cosmic Dust Grains (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The photoelectric emission process is considered to be the dominant mechanism for charging of cosmic dust grains in many astrophysical environments. The grain charge and the equilibrium potentials play an important role in the dynamical and physical processes that include heating of the neutral gas in the interstellar medium, coagulation processes in the dust clouds, and levitation and dynamical processes in the interplanetary medium and planetary surfaces and rings. An accurate evaluation of photoelectric emission processes requires knowledge of the photoelectric yields of individual dust grains of astrophysical composition as opposed to the values obtained from measurements on flat surfaces of bulk materials, as it is generally assumed on theoretical considerations that the yields for the small grains are much higher than the bulk values. We present laboratory measurements of the photoelectric yields of individual dust grains of silica, olivine, and graphite of approximately 0.09 to 8 microns radii levitated in an electrodynamic balance and illuminated with W radiation at 120 to 160 nm wavelengths. The measured values and the size dependence of the yields are found to be substantially different from the bulk values given in the literature.
    Keywords: Astrophysics
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    Chandra X-Ray Observatory Observations of the Jovian System (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Chandra X-ray Observatory (CXO) and XMM-Newton observations of x-rays from the Jovian system have answered questions that arose from early observations with the Einstein and Rosat X-ray Observatories, but in the process of vastly increasing our knowledge of x-ray emission from Jupiter and its environs they have also raised new questions and point to new opportunities for future studies. We will review recent x-ray results on the Jovian system, from the point of view of the CXO, and discuss various questions that have arisen in the course of our studies. We will discuss prospects for more observations in the immediate future, and how they might address open questions. Finally we will briefly describe ways in which an imaging x-ray spectrometer in the vicinity of the Jovian system could provide a wealth of data and results concerning Jupiter's x-ray auroral and disk emission, elemental abundance measurements for the Galilean moons, and detailed studies of x-ray emission from the Io Plasma Torus.
    Keywords: Astrophysics
    Type: 37th Annual Meeting of the Division of Planetary Sciences of the American Astronomical Society; Sep 04, 2005 - Sep 09, 2005; Cambridge; United Kingdom
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    Tomography of a Gamma-ray Burst Progenitor and its Host Galaxy (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: We have obtained near-infrared and high-resolution optical spectroscopy of the bright afterglow of the very intense gamma-ray burst recorded on 2002, October 4 (GRB 021004). Besides of line emission in the near-IR allowing an independent measurement of the systemic redshift (z = 2.3304 plus or minus 0.0005), we find several absorption line groups spanning a range of about 3,000 kilometers per second in velocity relative to the redshift of the host galaxy. The absorption profiles are very complex with both velocity-broadened components extending over several 100 kilometers per second and narrow lines with velocity widths of only approximately 20 kilometers per second. By analogy with QSO absorption line studies, the relative velocities, widths, and degrees of ionization of the lines ("line-locking", "ionization-velocity correlation") show that the progenitor had both an extremely strong radiation field and several distinct mass loss phases (winds). These results are consistent with GRB progenitors being massive stars, such as Luminous Blue Variables (LBVs) or Wolf-Rayet stars, providing a detailed picture of the spatial and velocity structure of the GRB progenitor star at the time of explosion. The host galaxy is a prolific star-forming galaxy with a SFR of approximately 10 solar mass yr(sup -l).
    Keywords: Astrophysics
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    The Mid-Infrared Absorption Spectra of Neutral PAHs in Dense Interstellar Clouds (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Polycyclic aromatic hydrocarbons (PAHs) are common throughout the universe and are expected to be present in dense interstellar clouds. In these environments, some P.4Hs may be present in the gas phase, but most should be frozen into ice mantles or adsorbed onto dust grains and their spectral features are expected to be seen in absorption. Here we extend our previous work on the infrared spectral properties of the small PAH naphthalene (C10H8) in several media to include the full mid-infrared laboratory spectra of 11 other PAHs and related aromatic species frozen in H2O ices. These include the molecules 1,2-dihydronaphthalene, anthracene, 9,1O-dihydroanthracene, phenanthrene, pyrene, benzo[e]pyrene, perylene, benzo(k)fluoranthene, pentacene, benzo[ghi]perylene, and coronene. These results demonstrate that PAHs and related molecules, as a class, show the same spectral behaviors as naphthalene when incorporated into H2O-rich matrices. When compared to the spectra of these same molecules isolated in inert matrices (e.g., Ar or N2), the absorption bands produced when they are frozen in H2O matrices are broader (factors of 3-10), show small position shifts in either direction (usually 〈 4/cm, always 〈 10/cm), and show variable changes in relative band strengths (typically factors of 1-3). There is no evidence of systematic increases or decreases in the absolute strengths of the bands of these molecules when they are incorporated in H2O matrices. In H2O-rich ices, their absorption bands are relatively insensitive to concentration over the range of 10 〈 H2O/PAH 〈 200): The absorption bands of these molecules are also insensitive to temperature over the 10 K 〈 T 〈 125 K range, although the spectra can show dramatic changes as the ices are warmed through the temperature range in which amorphous H2O ice converts to its cubic and hexagonal crystalline forms (T 〉 125 Kj. Given the small observed band shifts cause by H2O, the current database of spectra from Ar matrix-isolated neutral PAHs and related molecules should be useful for the search for these species in dense clouds on the basis of observed absorption band positions. Furthermore, these data permit determination of column densities to better than a factor of 3 for PAHs in dense clouds. Column density determination of detected aromatics to better than a factor of 3 will, however, require good knowledge about the nature of the matrix in which the PAH is embedded and laboratory studies of relevant samples.
    Keywords: Astrophysics
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    From Astrochemistry to Astrobiology (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Tremendous strides have been made in our understanding of interstellar material over the past twenty five years thanks to significant developments in observational astronomy and laboratory astrophysics. Twenty years ago the composition of interstellar dust was largely guessed at, the concept of ices in dense molecular clouds ignored, and the notion of large, abundant, gas phase, carbon-rich molecules widespread throughout the interstellar medium (ISM) considered impossible. Today the composition of interstellar dust is reasonably well understood. In molecular clouds, the birthplace of stars and planets, these cold dust particles are coated with mixed molecular ices whose composition is very well constrained. Lastly, the signature of carbon-rich polycyclic aromatic hydrocarbons (PAHs), shockingly large molecules by early interstellar chemistry standards, is widespread throughout the Universe. The first part of this talk will describe how infrared spectroscopic studies of interstellar space, combined with laboratory simulations of interstellar ice chemistry, have revealed the widespread presence of interstellar PAHs and the composition of interstellar ices, the building blocks of comets. The remainder of the presentation will focus on the photochemical evolution of these materials and astrobiology. Within a molecular cloud, and especially the presolar nebula, materials frozen into the ices are photoprocessed by ultraviolet light and produce more complex molecules. As these materials are the building blocks of comets and related to carbonaceous micrometeorites, they are likely to have been important sources of complex materials delivered to the early Earth and their composition may be related to the origin of life.
    Keywords: Astrophysics
    Type: Astrochemistry Seminar; Oct 25, 2005 - Oct 29, 2005; IL; United States
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    The Minimum-Mass Surface Density of the Solar Nebula using the Disk Evolution Equation (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The Hayashi minimum-mass power law representation of the pre-solar nebula (Hayashi 1981, Prog. Theo. Phys.70,35) is revisited using analytic solutions of the disk evolution equation. A new cumulative-planetary-mass-model (an integrated form of the surface density) is shown to predict a smoother surface density compared with methods based on direct estimates of surface density from planetary data. First, a best-fit transcendental function is applied directly to the cumulative planetary mass data with the surface density obtained by direct differentiation. Next a solution to the time-dependent disk evolution equation is parametrically adapted to the planetary data. The latter model indicates a decay rate of r -1/2 in the inner disk followed by a rapid decay which results in a sharper outer boundary than predicted by the minimum mass model. The model is shown to be a good approximation to the finite-size early Solar Nebula and by extension to extra solar protoplanetary disks.
    Keywords: Astrophysics
    Type: 2005 DPS Meeting; Sep 02, 2005 - Sep 09, 2005; Cambridge; United Kingdom
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    Six Years of Science with the Chandra X-Ray Observatory (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: The Chandra X-ray Observatory had its origins in a 1963 proposal led by Riccardo Giacconi that called for a 1-meter diameter, 1-arcsecond class X-Ray telescope for studying the Universe in X-rays. We will briefly discuss the history of the mission, the development of the hardware, its testing, and the launch on 1999, July 23. The remainder of the talk will be an admittedly eclectic review of some of the most exciting scientific highlights. These include the detection and identification of the first source seen with Chandra - an unusual Seyfert 1 we nicknamed Leon X-1, the detailed study of the Crab Nebula and its pulsar, and spectacular images of other supernova remnants including a 1-Million second exposure on Cas A. We also will summarize some of the major Chandra findings for normal and active galaxies and we will illustrate the breadth of science enabled by Chandra observations of clusters of galaxies and their implications for cosmology.
    Keywords: Astrophysics
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    Magnetars (2005)
    In:  Other Sources
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    Publication Date: 2019-07-18
    Description: Magnetars (Soft Gamma Repeaters and Anomalous X-ray Pulsars) are a subclass of neutron stars characterized by their recurrent X-ray bursts. While in an active (bursting) state, they are emitting hundreds of predominantly soft (kT=30 keV), short (0.1-100 ms long) events. Active states last anywhere between days and years. Their quiescent source X-ray light curves exhibit pulsations in the narrow range of 5-11 s; estimates of their rotational period rate changes (spin-down) indicate that their magnetic fields are extremely high, of the order of 10^14-10^15 G. Such high B-field objects, dubbed "magnetars", had been predicted to exist in 1992, but the first ccncrete observational evidence was obtained in 1998 for two of these sources. I will discuss here the recent spectacular results from SGR 1806-20, as well as the history of magnetars, and their spectral, timing and flux characteristics both in the persistent and their burst emission.
    Keywords: Astrophysics
    Type: A Life With Stars; Aug 21, 2005 - Aug 26, 2005; Amsterdam; Netherlands
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    Space Studies Board Annual Report, 2005 (2005)
    In:  Other Sources
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    Publication Date: 2019-08-24
    Description: The National Academy of Sciences (NAS) was chartered by Congress, under the leadership of President Abraham Lincoln, to provide scientific and technical advice to the government of the United States. Over the years, the advisory program of the institution has expanded, leading to the establishment of the National Academy of Engineering (NAE) and the Institute of Medicine, and of the National Research Council (NRC), the operational arm of the National Academies. The original charter of the Space Science Board was established in June 1958, three months before NASA opened its doors. The Space Science Board and its successor, the Space Studies Board (SSB), have provided expert external and independent scientific and programmatic advice to NASA on a continuous basis from NASA's inception until the present. The Board has also provided such advice to other agencies, including the National Oceanic and Atmospheric Administration, the National Science Foundation, the U.S. Geological Survey, and the Department of Defense, and responds to requests from Congress. Early in 2005, the leadership of NASA changed, and with it new emphases emerged. Some of the early interpretations of the 2004 Vision for Space Exploration, in which only certain aspects of space science were encouraged, disappeared and a broader mandate for science emerged. But what also emerged was fiscal reality, which precluded many of the exciting activities that were planned for NASA's science programs. In this environment of change, there has been a continuing need to evaluate NASA's plans against the strategies for science that have been laid down in the various NRC decadal surveys, and to assist NASA in determining how best to proceed given the reduced level of resources it will have. Coupled with this has been a continuing need to provide Congress with the assessments of NASA's plans that it requests.
    Keywords: Astrophysics
    Type: PB2011-101833
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    Modeling of the EUV and X-Ray Emission Spectra Induced by the Solar Winds Ions in the Heliosphere (2005)
    In:  CASI
    Details
    Publication Date: 2019-08-16
    Description: We have carried out investigation of the EUV and X-ray emission spectra induced in interaction between the Solar Wind (SW) and interstellar neutral gas. The spectra of most important SW ions have been computed for the charge-exchange mechanism of X-ray emission using new accurate spectroscopic data from recent laboratory measurements and theoretical calculations. Total spectra have been constructed as a sum of spectra induced in the charge-exchange collisions by individual O(exp q+), C(exp q+), N(exp q+), Ne(exp q+), Mg (exp q+) and Fe(exp q+) ions. Calculations have been performed for X-ray emission from the heliospheric hydrogen and helium gas. X-ray maps of the heliosphere have been computed. The power density of X-ray sources in the heliospheric ecliptic plane is shown for the H gas and for the He gas. Distances from the Sun (0,0) are given in AU. The helium cone is clear seen in the X-ray map of the charge-exchange emission induced by the solar wind. X-ray emission spectra detected by the Chandra X-ray telescope from the "dark" side of Moon has been identified as a X-ray background emission induced by the solar wind from the geocorona. Spectra and intensities of this charge-exchange X-rays have been compared with the heliospheric component of the X-ray background. Observations and modeling of the SW spectra induced from the geocorona indicate a strong presence of emission lines of highly charged oxygen ions. Anisotropy in distribution of heliospheric X-rays has been predicted and calculated for the regions of the fast and slow solar winds.
    Keywords: Astrophysics
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    Beyond Einstein: From the Big Bang to Black Holes (2005)
    In:  CASI
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    Publication Date: 2019-08-15
    Description: How did the Universe begin? Does time have a beginning and an end? Does space have edges? The questions are clear and simple. They are as old as human curiosity. But the answers have always seemed beyond the reach of science. Until now. In their attempts to understand how space, time, and matter are connected, Einstein and his successors made three predictions. First, space is expanding from a Big Bang; second, space and time can tie themselves into contorted knots called black holes where time actually comes to a halt; third, space itself contains some kind of energy that is pull- ing the Universe apart. Each of these three predictions seemed so fantastic when it was made that everyone, including Einstein himself, regarded them as unlikely. Incredibly, all three have turned out to be true. Yet Einstein's legacy is one of deep mystery, because his theories are silent on three questions raised by his fantastic predictions: (1) What powered the Big Bang? (2) What happens to space, time, and matter at the edge of a black hole? (3) What is the mysterious dark energy pulling the Universe apart? The answers to these questions-which lie at the crux of where our current theories fail us-will lead to a profound, new understanding of the nature of time and space. To find answers, however, we must venture beyond Einstein. The answers require new theories, such as the inflationary Universe and new insights in high-energy particle theory. Like Einstein s theories, these make fantastic predictions that seem hard to believe: unseen dimensions and entire universes beyond our own. We must find facts to confront and guide these new theories. Powerful new technologies now make this possible. And NASA and its partners are developing an armada of space-based observatories to chart the path to discovery. Here is where the Beyond Einstein story begins. By exploring the three questions that are Einstein s legacy, we begin the next revolution in understanding our Universe. We plot our way forward using clues from observations and from new ideas connecting the worlds of the very small and the very large, from the atom out through the deepest reaches of the cosmos.
    Keywords: Astrophysics
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    QPO Constraints on Neutron Stars (2005)
    In:  CASI
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    Publication Date: 2019-08-15
    Description: The kilohertz frequencies of QPOs from accreting neutron star systems imply that they are generated in regions of strong gravity, close to the star. This suggests that observations of the QPOs can be used to constrain the properties of neutron stars themselves, and in particular to inform us about the properties of cold matter beyond nuclear densities. Here we discuss some relatively model-insensitive constraints that emerge from the kilohertz QPOs, as well as recent developments that may hint at phenomena related to unstable circular orbits outside neutron stars.
    Keywords: Astrophysics
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    Unveiling the Engines in QSOs: Multi-Wavelength Study (2005)
    In:  CASI
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    Publication Date: 2019-07-11
    Description: UV/optical emission lines offer some of the most detailed information obtainable about the intrinsic properties of quasars. Studies of the density, ionization and metal abundance of gas near the accreting black hole are probed through an intriguing but poorly understood complex of correlations between emission lines and overall quasar spectral energy distributions that has long suffered from a lack of large, consistently measured samples. As part of a broader effort to expand and systematize the data upon which these studies are built, we proposed to NASA to model, fit, and measure UV/optical emission line parameters in large samples of quasar spectra. As part of the project, we developed an automated measurement technique that accounts for galactic reddening, includes iron emission blends, galactic and intrinsic absorption lines, and performs multi-component fits to the emission line profiles. We present measured line parameters (equivalent width and FWHM) for a large number of (28) different UV/optical lines, including upper limits for undetected lines.
    Keywords: Astrophysics
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    Constraints on Grain Formation Around Carbon Stars from Laboratory Studies of Presolar Graphite (2005)
    In:  CASI
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    Publication Date: 2019-07-11
    Description: We report the results of an investigation into the physical conditions in the mass outflows of asymptotic giant branch (AGB) carbon stars that are required for the formation of micron-sized presolar graphite grains, either with or without internal crystals of titanium carbide (TiC). In addition to providing detailed information about stellar nucleosynthesis, the structure and composition of presolar grains give unique information about the conditions of grain formation. In the present work we use laboratory observations of presolar graphite to gain insight into the physical conditions in circumstellar outflows from carbon AGB stars. The periodic pulsation of AGB stars enhances the gas density through shocks in the stellar atmosphere above the photosphere, promoting the condensation of dust grains. Copious mass outflow occurs largely because grains are coupled to the radiation field of the star, which accelerates them by radiation pressure; momentum is in turn transferred to gas molecules by collisions with grains. The dust/gas mixture is effectively a two-component fluid whose motion depends on atmospheric structure and which, in turn, influences that structure. In particular, the radiation pressure on the grains determines the velocity field of the outflow and thus the density distribution, while the density distribution itself determines the conditions of radiative transfer within the outflow and thus the effective radiation pressure.
    Keywords: Astrophysics
    Type: Lunar and Planetary Science XXXVI, Part 2; LPI-Contrib-1234-Pt-2
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    The Physical Nature of the Sharp Spectral Feature at 7 keV Detected in 1H0707-495 (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-11
    Description: XMM-Newton acquired data on the accepted target, 1H0707-495, on 2002 October 13 during revolution 0521. The observation was successful, with only about 5% data loss due to background flaring. We compared the data from this observation with earlier data taken on this Narrow-Line Seyfert 1 about two years before, performing interpretation studies in the context of the partial-covering model. Our second longer observation once again displays a sharp (〈 200 eV) spectral drop above 7 keV. However, in comparison to the first observation, the edge depth and energy have changed significantly. In addition to changes in the edge parameters, the high-energy spectrum appears steeper. The changes in the high-energy spectrum can be adequately explained in terms of a partial-covering absorber out-flowing from the central region. The low-energy spectrum also shows significant long-term spectral variability, including (1) a substantial increase in the disk temperature, (2) detection of an approx. 0.9 keV emission feature, and (3) the presence of ionized absorption that was detected during the ASCA mission. The large increase in disk temperature, and the more modest rise in luminosity, can be understood if we consider a slim-disk model for 1H0707-495. In addition, the higher disk luminosity could be the driving force behind the outflow and the re-appearance of an ionized medium during the second XMM-Newton observation.
    Keywords: Astrophysics
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    High-energy Absorption in Blazars: Probing the Inner Jet Environment (2005)
    In:  CASI
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    Publication Date: 2019-07-11
    Description: This grant was awarded to perform the analysis and interpretation of proprietary and archival X-ray and multiwavelength observations of blazar jets. The main goals of the project were to: (1) characterize the spectral and variability properties of blazar jets, to understand their emission mechanisms and physical parameters, and 2) investigate the small- and large-scale X-ray environment of blazars, to gain insights on the gas responsible for confining the jet. Progress on both areas has been made, as detailed below.
    Keywords: Astrophysics
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    Science with Constellation-X (2005)
    In:  CASI
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    Publication Date: 2019-07-11
    Description: NASA's upcoming Constellation-X mission, one of two flagship missions in the Beyond Einstein program, will have more than 100 times the collecting area of any previous spectroscopic mission operating in the 0.25-40 keV bandpass and will enable high-throughput, high spectral resolution studies of sources ranging from the most luminous accreting supermassive black holes in the Universe to the disks around young stars where planets form. This booklet, which was assembled during early 2005 using the contributions of a large team of Astrophysicists, outlines the important scientific questions for the decade following this one and describes the areas where Constellation-X is going to have a major impact. These areas include the exploration of the space-time geometry of black holes spanning nine orders of magnitude in mass and the nature of the dark energy and dark matter which govern the expansion and ultimate fate of the Universe. Constellation-X will also explore processes referred to as "cosmic feedback" whereby mechanical energy, radiation, and chemical elements from star formation and black holes are returned to interstellar and intergalactic medium, profoundly affecting the development of structure in the Universe, and will also probe all the important life cycles of matter, from stellar and planetary birth to stellar death via supernova to stellar endpoints in the form of accreting binaries and supernova remnants.
    Keywords: Astrophysics
    Type: NASA/TP-2005-212784 , Rept-2005-01561-0
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    Studying Dark Energy, Black Holes and Cosmic Feedback at X-ray Wavelengths: NASA's Constellation-X Mission (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Among the most important topics in modern astrophysics are the nature of the dark energy equation of state, the formation and evolution of supermassive black holes in concert with galaxy bulges, and the self-regulating symmetry imposed by both stellar and AGN feedback. All of these topics are readily addressed with observations at X-ray wavelengths. For instance, theoretical models predict that the majority (98%) of the energy and metal content in starburst superwinds exists in the hot million-degree gas. The Constellation-X observatory is being developed to perform spatially resolved high-resolution X-ray spectroscopy so that we may directly measure the absolute element abundances and velocities of this hot gas. This talk focuses on the driving science behind this mission, which is one of two flagship missions in NASA's Beyond Einstein program. A general overview of the observatory's capabilities and basic technology will also be given.
    Keywords: Astrophysics
    Type: Nearly Normal Galaxies 2005 Conference; Aug 08, 2005 - Aug 12, 2005; Santa Cruz, CA; United States
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  • 92
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    Beyond Einstein: Exploring the Extreme Universe (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: This paper will give an overview of the NASA Universe Division Beyond Einstein program. The Beyond Einstein program consists of a series of exploratory missions to investigate some of the most important and pressing problems in modern-day astrophysics - including searches for Dark Energy and studies of the earliest times in the universe, during the inflationary period after the Big Bang. A variety of new technologies are being developed both in the science instrumentation these missions will carry and in the spacecraft that will carry those instruments.
    Keywords: Astrophysics
    Type: AIAA Conference Proceedings, Space 2005; Aug 30, 2005 - Sep 01, 2005; Long Beach, CA; United States
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  • 93
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    Variations in the Peak Position of the 6.2 micron Interstellar Emission Feature: A Tracer of N in the Interstellar Polycyclic Aromatic Hydrocarbon Population (2005)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: This paper presents the results of an investigation of the molecular characteristics that underlie the observed peak position and profile of the nominal 6.2 micron interstellar emission band generally attributed to the CC stretching vibrations of polycyclic aromatic hydrocarbons (PAHs). It begins with a summary of recent experimental and theoretical studies ofthe spectroscopic properties of large (〉30 carbon atoms) PAH cations as they relate to this aspect of the astrophysical problem. It then continues with an examination of the spectroscopic properties of a number of PAH variants within the context of the interstellar 6.2 micron emission, beginning with a class of compounds known as polycyclic aromatic nitrogen heterocycles (PANHs; PAHs with one or more nitrogen atoms substituted into their carbon skeleton). In this regard, we summarize the results of recent relevant experimental studies involving a limited set of small PANHs and their cations and then report the results of a comprehensive computational study that extends that work to larger PANH cations including many nitrogen-substituted variants of coronene(+) (C24H12(+)), ovalene(+) (C32H14(+)), circumcoronene(+) (C54H18(+)), and circum-circumcoronene(+) (C96H24(+)). Finally, we report the results of more focused computational studies of selected representatives from a number of other classes of PAH variants that share one or more of the key attributes of the PANH species studied. These alternative classes of PAH variants include (1) oxygen- and silicon-substituted PAH cations; (2) PAH-metal ion complexes (metallocenes) involving the cosmically abundant elements magnesium and iron; and (3) large, asymmetric PAH cations. Overall, the studies reported here demonstrate that increasing PAH size alone is insuEcient to account for the position of the shortest wavelength interstellar 6.2 micron emission bands, as had been suggested by earlier studies. On the other hand, this work reveals that substitution of one or more nitrogen atoms within the interior of the carbon skeleton of a PAH cation induces a significant blueshift in the position of the dominant CC stretching feature of these compounds that is suf6cient to account for the position of the interstellar bands. Subsequent studies of the effects of substitution by other heteroatoms (O and Si), metal ion complexation (Fe(+), Mg(+), and Mg(2+)), and molecular symmetry variation-all of which fail to reproduce the blueshift observed in the PANH cations-indicate that N appears to be unique in its ability to accommodate the position of the interstellar 6.2 micron bands while simultaneously satisfying the other constraints of the astrophysical problem. This result implies that the peak position of the interstellar feature near 6.2 micron traces the degree of nitrogen substitution in the population, that most of the PAHs responsible for the interstellar IR emission features incorporate nitrogen within their aromatic networks, and that a lower limit of 1%-2% of the cosmic nitrogen is sequestered within the interstellar PAH population. Finally, in view of the ubiquity and abundance of interstellar PAHs and the permanent dipoles and distinctive electronic structures of these nitrogen-substituted variants, this work impacts a wide range of observational phenomena outside of the infrared region of the spectrum including the forest of unidentified molecular rotational features and the anomalous Galactic foreground emission in the microwave, and the diffuse interstellar bands (DIBs) and other structure in the interstellar extinction curve in the ulhviolet/visible. These astrophysical ramifications are discussed, and the dipole moments and rotational constants are tabulated to facilitate further investigations of the astrophysical role of nitrogen-substituted aromatic compounds.
    Keywords: Astrophysics
    Type: The Astrophysical Journal; 632; 316-332
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  • 94
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    INTEGRAL Observations of the Galactic 511 keV Emission and MeV Gamma-ray Astrophysics (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Although there are a number of interesting phenomena, such as Nucleosynthesis in stars, in the MeV energy region, the observations have been difficult due to a small signal to noise (background) ratio (less than 1%). While NASA's Compton Gamma-ray Observatory (CGRO) enabled us to explore the Gamma-ray universe, ESA's INTEGRAL mission, launched in 2002, is providing us more detailed information with its superior energy and angular resolution. We will briefly discuss some of the current issues in MeV Gamma-ray Astrophysics. Then, we will focus on the Galactic 511 keV emission with the latest INTEGRAL observations, and talk about challenges we currently have.
    Keywords: Astrophysics
    Type: Rironkon Symposium; Dec 25, 2005 - Dec 27, 2005; Kyoto; Japan
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  • 95
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    Confirmation Of Thick Whim At Z-0.1 In Sculptor Supercluster (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: This grant is associated to an XMM observation of the quasar QSO Q0056-363(PI: Dr. Roberto Maiolino), which is one of the brightest quasars in the X-ray sky, and it lies in the general direction of the Sculptor Supercluster, and behind it. We requested the observation to check a previous hint of existence of an absorption features by highly ionized gas at the redshift of the Supercluster, which we supposed to be the imprint of a Warm-Hot Intergalactic Medium filament connecting the already virialized structures in the Supercluster. The observation suffered a high background, and so the net exposure was considerably reduced compared to the requested exposure. Additionally the quasar turned out to be in a quite low level of activity. These two unfortunate facts made it impossible to confirm or rule-out at high resolution (i.e. with the RGS) the existence of the previously hinted OW1 K-alpha resonant line at the redshift of the Sculptor Supercluster, the new RGS data being sensitive only to equivalent width of unresolved absorption lines of about 30-50 mA at 1-sigma. The data, however, shows a very strong absorption line in a position different from the OVII/OVIII K-alpha at the redshift of the Supercluster. If this line is interpreted as OVII/OVIII K-alpha absorption, the redshift of this WHIM filament would lie in a region of the Universe where no visible virialized concentrations are present. This would confirm the relatively high probability of detecting WHIM filaments in apparent 'void' regions of the Universe (as previously suggested by our first detection of WHIM filaments at z greater than 0 along the line of sight to the blazar Mkn 421). A paper on the non-detection of any WHIM filament at the redshift of the Sculptor Supercluster, as well as on the detection of this putative WHIM filament in a 'void', will be shortly submitted to the ApJ.
    Keywords: Astrophysics
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  • 96
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    Participation in the Analysis of the Far-Infrared/Submillimeter Interferometer (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: We have contributed to the development of the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS) by analyzing various aspects related to the tethers that connect the spacecraft of this space interferometer. We have focused our analysis on key topics as follows: (a) helping in the configuration selection; (b) computing the system eigenfrequencies as a function of baseline length; (c) developing techniques and conceptual design of devices for damping the tether oscillations; (d) carrying out numerical simulations of tethered formation to assess the effects of environmental perturbations upon the baseline length variation; (e) devising control laws for fast retargeting of the interferometer at moderate baseline lengths; (f) estimating the survivability to micrometeoroid impacts of a tether at L2; and (g) developing a conceptual design of a high-strength and survivable tether.
    Keywords: Astrophysics
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  • 97
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    Seeing Red and Shooting Blanks: Study of Red Quasars and Blank X-Ray Sources (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: A major paper describing the technique and providing a list of 'blanks' was published in the Astrophysical Journal (abstract below). The results revealed a fascinating trove of novel X-ray sources: high redshift clusters of galaxies found efficiently; X-ray absorbed, optically clean AGN, which may be the bright prototypes of Chandra Deep Survey sources; and several with a still unknown nature. Recent XMM-Newton results confirm the existence of this class of X-ray source with much refined positions. During the first year of this project we have made a major discovery. The second 'blanks' X-ray source observed with Chandra was found to be extended. Using Chandra data and ground-based R and K band imaging we estimated this to be a high redshift cluster of galaxies with z approx. 0.85. Spectroscopy agrees with this estimate (z=0.89). This success shows that our method of hunting down 'blank' field X-ray sources is a highly efficient method of finding the otherwise elusive high redshift clusters. With extensive follow-up we should be able to use 'blanks' to make cosmological tests. The paper is now in press in the Astrophysical Journal (abstract below.) The other Chandra source is point-like, showing that there are a variety of 'blank' source types. Other follow-up observations with XMM-Newton, and (newly approved in cycle 2) with Chandra are eagerly awaited. A follow-up paper uses a large amount of supporting data for the remaining blanks. A combination of ROSAT, Chandra and ground based data convincingly identified one of the blanks as a Ultra-luminous X-ray source (ULX) in a spiral galaxy (abstract below). This program resulted in 3 refereed papers in major journals, 4 conference proceedings and a significant fraction of the PhD thesis of Dr. Ilaria Cagnoni. Details of the publications are given.
    Keywords: Astrophysics
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  • 98
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    High Resolution Spectroscopy And Timing Of The Isolated Neutron Star RBS 1774 (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The 2004 May 31 XMM-Newton observation was reprocessed using SASv6.0.0 and times of high background were filtered out. The net exposure time remaining was 23 ks. The source was clearly detected in MOS1, MOS2 and PN chips. We performed both timing and spectroscopic analysis on the data. We performed a spectral analysis by fitting data from the three EPIC detectors simultaneously, finding that the broadband spectrum can be represented by a single absorbed blackbody, with kT = 0.10 keV. The fitting revealed the presence of an absorption feature at 0:7 keV, but the data did have enough resolution to allow us to discriminate between an absorption line and an edge. We also tested magnetized models of Pavlov et a1 and Zavlin et al, but found that fits with these models were considerably worse than with a blackbody. For the timing analysis, we extracted the counts within a 3000 radius aperture in both PN and MOS 1 and MOS2 but with the aperture truncated by a chord where it approached the edge of the CCD window in each case: this maximized the counts while avoiding any edge effects. We analyzed PN, MOSl and MOS2 data both individually and combined using the Maximum Likelihood Periodogram technique of Zane et al. (2002) and Cropper et al. (2004). Periods from 10000 s to 30 ms were searched, ensuring that in each case the period grid was 2.5 times better sampled than the Nyquist frequency. The search revealed a significant period at 9.437s. Taken overall, we found the characteristics of RBS 1774 to be remarkably similar to those of another X-ray faint isolated neutron stars. These results were written up for the Astrophysical Journal, and the paper has recently been accepted for publication.
    Keywords: Astrophysics
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  • 99
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    A Detailed Study of Two Optically-selected, High-redshift Clusters of Galaxies (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: This grant final report lists bibliographic citations for three papers published through support of NAG5-11347 "A Detailed Study of Two Optically-Selected, High Red-Shift Clusters of Galaxies."
    Keywords: Astrophysics
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  • 100
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    Feasibility study of ferromagnetic/ferroelectric films for enhanced microwave devices (2005)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: This report summarizes exploratory work conducted to assess the feasibility of ferromagnetic/ferroelectric films for next-generation microwave devices. From literature review, it is established that while an increasing number of ferroelectric/ferromagnetic composites are being investigated, a number have transition temperatures that are too low and structures that are not robust enough for low cost, room temperature antenna arrays. On the other hand, several promising systems are identified, including the multiferroic BiFeO3 and a composite system of Ba/SrTiO3 and a related perovskite manganite. It is suggested that when the NASA pulsed laser deposition chamber is fully operational, thin films of these systems be investigated. In preparation for such work, we have reconfirmed several structural features of an existing Ba/SrTiO3 film using the x-ray diffractometer at Oberlin College.
    Keywords: Astrophysics
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