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  • 1
    ISSN: 0044-2313
    Keywords: Selenites ; hydrates ; X-ray ; IR ; crystal structure ; pseudosymmetry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polymorphic and Pseudosymmetrical Hydrates MSeO3 · H2O (M = Mn, Co, Ni, Zn, Cd)By crystallization from aqueous solutions of MSeO3 and M(HSeO3)2, the selenites MSeO3 · H2O (M = Mn, Co, Ni, Zn, Cd) were obtained and characterized by means of X-ray diffraction and IR-spectroscopy. The crystal structure of ZnSeO3 · H2O was determined. The IR spectra indicate that the hydrates are isotypic and contain H2O molecules of symmetry mm2. However, the X-ray data show different structure types with H2O molecules of site symmetry m or 1. CdSeO3 · H2O and MnSeO3 · H2O are isotypic (o.rh., MnSeO3 · D2O type). CoSeO3 · H2O (mon.) as well as the isotypic NiSeO3 · H2O and ZnSeO3 · H2O (mon.) form new structure types. These findings are discussed on the basis of the crystal structure of ZnSeO3 · H2O (P21/n, a = 477.9(1), b = 1319.4(5), c = 570.1(1) pm, β = 90.84(2)°, Z = 4, Dx = 3.886 g · cm-3, R = 0.035 for 722 reflections with I 〉 2σ1) and the local pseudosymmetry of its components, i.e., layers ∞2[ZnSeO3 · H2O] of ZnO6 octahedra sharing four equatorial vertices, SeO32- anions and H2O molecules.
    Notes: Durch Kristallisation aus MSeO3- und M(HSeO3)2-Lösungen wurden die Selenite MSeO3 · H2O (M = Mn, Co, Ni, Zn, Cd) erhalten und röntgenographisch sowie IR-spektroskopisch charakterisiert. Von ZnSeO3 · H2O wurde die Kristallstruktur bestimmt. Die IR-Spektren deuten auf Isotypie der Hydrate und H2O-Moleküle der Symmetrie mm2. Die Röntgenbeugungsdaten zeigen dagegen das Vorliegen verschiedener Strukturtypen mit H2O-Molekülen der Lagesymmetrie m oder 1. CdSeO3 · H2O und MnSeO3 · H2O sind isotyp (o.rh., MnSeO3 · D2O-Typ). CoSeO3 · H2O (mon.) sowie die isotypen NiSeO3 · H2O und ZnSeO3 · H2O (mon.) kristallisieren in neuen Strukturtypen. Diese Befunde werden auf der Basis der Kristallstruktur von ZnSeO3 · H2O (P21/n, a = 477,9(1), b = 1319,4(5), c = 570,1(1) pm, β = 90,84(2)°, Z = 4, Dx = 3,886 g · cm-3, R = 0,035 für 722 Reflexe mit I 〉 2σ1) und der lokalen Pseudosymmetrie ihrer Bausteine (Schichten ∞2[ZnSeO3 · H2O] aus vierfach eckenverknüpften ZnO6-Oktaedern, SeO32--Anionen und H2O-Moleküle) diskutiert.
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  • 2
    ISSN: 0044-2313
    Keywords: Hydrogen selenites ; crystal structure ; IR ; Raman heating ; thermal analysis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Hydrates M(HSeO3)2 · 4H2O (M = Mg, Co, Ni, Zn) - Crystal Structures, IR, Raman, and Thermoanalytical InvestigationsFrom aqueous solutions of M(HSeO3)2 single crystals of Mg(HSeO3)2 · 4H2O and of the hitherto unknown compounds Co(HSeO3)2 · 4H2O, Ni(HSeO3)2 · 4H2O and Zn(HSeO3)2 · 4H2O could be obtained. The crystal structures, X-ray powder, IR, Raman and thermoanalytical (DTA, TG, Raman heating) data are presented and discussed. The crystal data of the isotypic compounds are: monoclinic, space group C2/c, Z = 4, Mg: a = 1 464.6(2), b = 755.3(1), c = 1 099.9(1) pm, β = 126.59(1)°, V = 0.9769(1) nm3, Co: a = 1 462.5(2), b = 756.5(2), c = 1 102.2(2) pm, β = 126.53(1)°, V = 0.9798(2) nm3, Ni: a = 1 452.2(2), b = 751.0(1), c = 1 091.5(1) pm, β = 126.28(1)°, V = 0.9595(1) nm3, Zn: a = 1 468.3(2), b = 755.8(1), c = 1 103.1(1) pm, β = 126.79(1)°, V = 0.9804(2) nm3. The crystal structures consist of hexagonal packed [M(HSeO3)2 · 2H2O]n chains of [MO4(H2O)2] octahedra linked by Se atoms. They contain trigonal pyramidal SeO2OH-ions with “free” hydroxyl groups and also “free” molecules of water of crystallization. The hydroxyl groups build strong H-bonds (O—H … O distances: 265-268 pm). The IR spectra show AB doublett bands in the OH stretching mode region of the hydroxyl groups. The water molecules of crystallization are linked to planar (H2O)4 tetramers by H-bonds with unusually short O—H … O bond distances of 271-273 pm. DTA and TG measurements indicate that thermal decomposition results in the direct formation of the respective diselenite MSe2O5. Raman heating measurements show under quasi static conditions the intermediate formation of the anhydrous hydrogen selenites.
    Notes: Aus M(HSeO3)2-Lösungen konnten erstmals Einkristalle von Mg(HSeO3)2 · 4H2O sowie die bisher nicht bekannten Verbindungen Co(HSeO3)2 · 4H2O, Ni(HSeO3)2 · 4H2O und Zn(HSeO3)2 · 4H2O erhalten werden. Die Kristallstrukturen, Röntgenpulverdaten, IR- und Raman-Spektren sowie die Ergebnisse thermoanalytischer (DTA, TG, Raman-Heizaufnahmen) Untersuchungen werden mitgeteilt und diskutiert. Die Kristalldaten der isotypen Verbindungen sind: monoklin, Raumgruppe C2/c, Z = 4, Mg: a = 1 464,6(2), b = 755,3(1), c = 1 099,9(1) pm, β = 126,59(1)°, V = 0,9769(1) nm3, Co: a = 1 462,5(2), b = 756,5(2), c = 1 102,2(2) pm, β = 126,53(1)°, V = 0,9798(2) nm3, Ni: a = 1 452,2(2), b = 751,0(1), c = 1 091,5(1) pm, β = 126,28(1)°, V = 0,9595(1) nm3, Zn: a = 1 468,3(2), b = 755,8(1), c = 1 103,1(1) pm, β = 126,79(1)°, V = 0,9804(2) nm3. Die Kristallstrukturen bestehen aus hexagonal gepackten [M(HSeO3)2 · 2H2O]n-Ketten Se-verbrückter [MO4(H2O)2]-Oktaeder. Sie enthalten trigonal pyramidale SeO2OH--Ionen mit „freien“ Hydroxylgruppen und „freie“ Kristallwassermoleküle. Die Hydroxylgruppen bilden starke H-Brücken (O—H … O-Abstände: 265-268 pm). Die IR-Spektren zeigen im Bereich der OH-Streckschwingungen der Hydroxylgruppen AB-Doublett-Banden. Die Kristallwassermoleküle sind zu planaren (H2O)4-Tetrameren mit ungewöhnlich kurzen O—H … Ow-Abständen (271 - 273 pm) H-verbrückt. Die thermische Zersetzung führt nach DTA- und TG-Messungen direkt zum jeweiligen Diselenit MSe2O5. Mittels Raman-Heizaufnahmen unter Quasi-Gleichgewichtsbedingungen konnte erstmals die intermediäre Bildung wasserfreier Hydrogenselenite beobachtet werden.
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  • 3
    Publication Date: 2009-07-15
    Description: The formation of a complex nervous system requires the intricate interaction of neurons and glial cells. Glial cells generally migrate over long distances before they initiate their differentiation, which leads to wrapping and insulation of axonal processes. The molecular pathways coordinating the switch from glial migration to glial differentiation are largely unknown. Here we demonstrate that, within the Drosophila eye imaginal disc, fibroblast growth factor (FGF) signalling coordinates glial proliferation, migration and subsequent axonal wrapping. Glial differentiation in the Drosophila eye disc requires a succession from glia-glia interaction to glia-neuron interaction. The neuronal component of the fly eye develops in the peripheral nervous system within the eye-antennal imaginal disc, whereas glial cells originate from a pool of central-nervous-system-derived progenitors and migrate onto the eye imaginal disc. Initially, glial-derived Pyramus, an FGF8-like ligand, modulates glial cell number and motility. A switch to neuronally expressed Thisbe, a second FGF8-like ligand, then induces glial differentiation. This switch is accompanied by an alteration in the intracellular signalling pathway through which the FGF receptor channels information into the cell. Our findings reveal how a switch from glia-glia interactions to glia-neuron interactions can trigger formation of glial membrane around axonal trajectories. These results disclose an evolutionarily conserved control mechanism of axonal wrapping, indicating that Drosophila might serve as a model to understand glial disorders in humans.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Franzdottir, Sigridur Rut -- Engelen, Daniel -- Yuva-Aydemir, Yeliz -- Schmidt, Imke -- Aho, Annukka -- Klambt, Christian -- England -- Nature. 2009 Aug 6;460(7256):758-61. doi: 10.1038/nature08167. Epub 2009 Jul 13.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Neurobiologie, Universitat Munster, Badestr. 9, D-48149 Munster, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19597479" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Axons/metabolism ; *Cell Differentiation ; Cell Movement ; Cell Proliferation ; Drosophila Proteins/metabolism ; Drosophila melanogaster/cytology/genetics/growth & development/*metabolism ; Eye/*cytology/growth & development/innervation/metabolism ; Fibroblast Growth Factors/*metabolism ; Guinea Pigs ; Ligands ; Neuroglia/*cytology/*metabolism ; *Signal Transduction
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 4
    Publication Date: 2015-05-23
    Description: Marine plankton support global biological and geochemical processes. Surveys of their biodiversity have hitherto been geographically restricted and have not accounted for the full range of plankton size. We assessed eukaryotic diversity from 334 size-fractionated photic-zone plankton communities collected across tropical and temperate oceans during the circumglobal Tara Oceans expedition. We analyzed 18S ribosomal DNA sequences across the intermediate plankton-size spectrum from the smallest unicellular eukaryotes (protists, 〉0.8 micrometers) to small animals of a few millimeters. Eukaryotic ribosomal diversity saturated at ~150,000 operational taxonomic units, about one-third of which could not be assigned to known eukaryotic groups. Diversity emerged at all taxonomic levels, both within the groups comprising the ~11,200 cataloged morphospecies of eukaryotic plankton and among twice as many other deep-branching lineages of unappreciated importance in plankton ecology studies. Most eukaryotic plankton biodiversity belonged to heterotrophic protistan groups, particularly those known to be parasites or symbiotic hosts.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉de Vargas, Colomban -- Audic, Stephane -- Henry, Nicolas -- Decelle, Johan -- Mahe, Frederic -- Logares, Ramiro -- Lara, Enrique -- Berney, Cedric -- Le Bescot, Noan -- Probert, Ian -- Carmichael, Margaux -- Poulain, Julie -- Romac, Sarah -- Colin, Sebastien -- Aury, Jean-Marc -- Bittner, Lucie -- Chaffron, Samuel -- Dunthorn, Micah -- Engelen, Stefan -- Flegontova, Olga -- Guidi, Lionel -- Horak, Ales -- Jaillon, Olivier -- Lima-Mendez, Gipsi -- Lukes, Julius -- Malviya, Shruti -- Morard, Raphael -- Mulot, Matthieu -- Scalco, Eleonora -- Siano, Raffaele -- Vincent, Flora -- Zingone, Adriana -- Dimier, Celine -- Picheral, Marc -- Searson, Sarah -- Kandels-Lewis, Stefanie -- Tara Oceans Coordinators -- Acinas, Silvia G -- Bork, Peer -- Bowler, Chris -- Gorsky, Gabriel -- Grimsley, Nigel -- Hingamp, Pascal -- Iudicone, Daniele -- Not, Fabrice -- Ogata, Hiroyuki -- Pesant, Stephane -- Raes, Jeroen -- Sieracki, Michael E -- Speich, Sabrina -- Stemmann, Lars -- Sunagawa, Shinichi -- Weissenbach, Jean -- Wincker, Patrick -- Karsenti, Eric -- New York, N.Y. -- Science. 2015 May 22;348(6237):1261605. doi: 10.1126/science.1261605.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. vargas@sb-roscoff.fr pwincker@genoscope.cns.fr karsenti@embl.de. ; CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. ; Department of Ecology, University of Kaiserslautern, Erwin-Schroedinger Street, 67663 Kaiserslautern, Germany. CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. ; Department of Marine Biology and Oceanography, Institute of Marine Science (ICM)-Consejo Superior de Investigaciones Cientificas (CSIC), Passeig Maritim de la Barceloneta 37-49, Barcelona E08003, Spain. ; Laboratory of Soil Biology, University of Neuchatel, Rue Emile-Argand 11, 2000 Neuchatel, Switzerland. ; CNRS, FR2424, Roscoff Culture Collection, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Sorbonne Universites, UPMC Paris 06, FR 2424, Roscoff Culture Collection, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. ; CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Ecole Normale Superieure, Institut de Biologie de l'ENS (IBENS), and Inserm U1024, and CNRS UMR 8197, Paris, F-75005 France. ; Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Genomique, GENOSCOPE, 2 rue Gaston Cremieux, 91000 Evry, France. ; CNRS FR3631, Institut de Biologie Paris-Seine, F-75005, Paris, France. Sorbonne Universites, UPMC Paris 06, Institut de Biologie Paris-Seine, F-75005, Paris, France. Ecole Normale Superieure, Institut de Biologie de l'ENS (IBENS), and Inserm U1024, and CNRS UMR 8197, Paris, F-75005 France. CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. ; Department of Microbiology and Immunology, Rega Institute, KU Leuven, Herestraat 49, 3000 Leuven, Belgium. Center for the Biology of Disease, VIB, Herestraat 49, 3000 Leuven, Belgium. Department of Applied Biological Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. ; Department of Ecology, University of Kaiserslautern, Erwin-Schroedinger Street, 67663 Kaiserslautern, Germany. ; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic. Faculty of Science, University of South Bohemia, Branisovska 31, 37005 Ceske Budejovice, Czech Republic. ; CNRS, UMR 7093, Laboratoire d'Oceanographie de Villefranche-sur-Mer (LOV), Observatoire Oceanologique, F-06230, Villefranche-sur-Mer, France. Sorbonne Universites, UPMC Paris 06, UMR 7093, LOV, Observatoire Oceanologique, F-06230, Villefranche-sur-Mer, France. ; Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Genomique, GENOSCOPE, 2 rue Gaston Cremieux, 91000 Evry, France. CNRS, UMR 8030, CP5706, Evry, France. Universite d'Evry, UMR 8030, CP5706, Evry, France. ; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic. Faculty of Science, University of South Bohemia, Branisovska 31, 37005 Ceske Budejovice, Czech Republic. Canadian Institute for Advanced Research, 180 Dundas Street West, Suite 1400, Toronto, Ontario M5G 1Z8, Canada. ; Ecole Normale Superieure, Institut de Biologie de l'ENS (IBENS), and Inserm U1024, and CNRS UMR 8197, Paris, F-75005 France. ; MARUM, Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany. CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. Sorbonne Universites, Universite Pierre et Marie Curie (UPMC) Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France. ; Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy. ; Ifremer, Centre de Brest, DYNECO/Pelagos CS 10070, 29280 Plouzane, France. ; Center for the Biology of Disease, VIB, Herestraat 49, 3000 Leuven, Belgium. Ecole Normale Superieure, Institut de Biologie de l'ENS (IBENS), and Inserm U1024, and CNRS UMR 8197, Paris, F-75005 France. ; Structural and Computational Biology, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany. Directors' Research, EMBL, Meyerhofstrasse 1, 69117 Heidelberg, Germany. ; Structural and Computational Biology, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany. Max-Delbruck-Centre for Molecular Medicine, 13092 Berlin, Germany. ; CNRS UMR 7232, Biologie Integrative des Organismes Marins (BIOM), Avenue du Fontaule, 66650 Banyuls-sur-Mer, France. Sorbonne Universites Paris 06, Observatoire Oceanologique de Banyuls (OOB) UPMC, Avenue du Fontaule, 66650 Banyuls-sur-Mer, France. ; Aix Marseille Universite, CNRS IGS UMR 7256, 13288 Marseille, France. ; Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan. ; PANGAEA, Data Publisher for Earth and Environmental Science, University of Bremen, Bremen, Germany. MARUM, Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany. ; Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA. National Science Foundation, Arlington, VA 22230, USA. ; Department of Geosciences, Laboratoire de Meteorologie Dynamique (LMD), Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris Cedex 05, France. Laboratoire de Physique des Oceans, Universite de Bretagne Occidentale (UBO)-Institut Universitaire Europeen de la Mer (IUEM), Place Copernic, 29820 Plouzane, France. ; Structural and Computational Biology, European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany. ; Commissariat a l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Genomique, GENOSCOPE, 2 rue Gaston Cremieux, 91000 Evry, France. CNRS, UMR 8030, CP5706, Evry, France. Universite d'Evry, UMR 8030, CP5706, Evry, France. vargas@sb-roscoff.fr pwincker@genoscope.cns.fr karsenti@embl.de. ; Directors' Research, EMBL, Meyerhofstrasse 1, 69117 Heidelberg, Germany. Ecole Normale Superieure, Institut de Biologie de l'ENS (IBENS), and Inserm U1024, and CNRS UMR 8197, Paris, F-75005 France. vargas@sb-roscoff.fr pwincker@genoscope.cns.fr karsenti@embl.de.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25999516" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Biodiversity ; DNA Barcoding, Taxonomic ; DNA, Ribosomal/genetics ; Eukaryota/*classification/genetics ; Oceans and Seas ; Phylogeny ; Plankton/*classification/genetics ; Ribosomes/genetics ; Sequence Analysis, DNA ; Sunlight
    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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  • 5
    Publication Date: 2019-07-31
    Description: A millimeter-wave survey over half the sky, that spans frequencies in the range of 30 to 350 gigahertz, and that is both an order of magnitude deeper and of higher-resolution than currently funded surveys would yield an enormous gain in understanding of both fundamental physics and astrophysics. By providing such a deep, high-resolution millimeter-wave survey (about 0.5 microK-arcminutes noise and 15 arcseconds resolution at 150 gigahertz), CMB-HD (Cosmic Microwave Background - Henry Draper catalog entry) will enable major advances. It will allow 1) the use of gravitational lensing of the primordial microwave background to map the distribution of matter on small scales (k approximately equal to 10 h per megaparsec), which probes dark matter particle properties. It will also allow 2) measurements of the thermal and kinetic Sunyaev-Zeldovich effects on small scales to map the gas density and gas pressure profiles of halos over a wide field, which probes galaxy evolution and cluster astrophysics. In addition, CMB-HD would allow us to cross critical thresholds in fundamental physics: 3) ruling out or detecting any new, light (less than 0.1 electronvolts), thermal particles, which could potentially be the dark matter, and 4) testing a wide class of multi-field models that could explain an epoch of inflation in the early Universe. Such a survey would also 5) monitor the transient sky by mapping the full observing region every few days, which opens a new window on gamma-ray bursts, novae, fast radio bursts, and variable active galactic nuclei. Moreover, CMB-HD would 6) provide a census of planets, dwarf planets, and asteroids in the outer Solar System, and 7) enable the detection of exo-Oort clouds around other solar systems, shedding light on planet formation. The combination of CMB-HD with contemporary ground and space-based experiments will also provide powerful synergies. CMB-HD will deliver this survey in 5 years of observing 20,000 square degrees, using two new 30-meter-class off-axis cross-Dragone telescopes to be located at Cerro Toco in the Atacama Desert. The telescopes will field about 2.4 million detectors (600,000 pixels) in total. The CMB-HD survey will be made publicly available, with usability and accessibility a priority.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN70476
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  • 6
    Publication Date: 2019-10-23
    Description: The Simons Observatory (SO) is a ground-based cosmic microwave background (CMB) experiment sited on Cerro Toco in the Atacama Desert in Chile that promises to provide breakthrough discoveries in fundamental physics, cosmology, and astrophysics. Supported by the Simons Foundation, the Heising-Simons Foundation, and with contributions from collaborating institutions, SO will see first light in 2021 and start a five year survey in 2022. SO has 287 collaborators from 12 countries and 53 institutions, including 85 students and 90 postdocs. The SO experiment in its currently funded form (SO-Nominal) consists of three 0.4 m Small Aperture Telescopes (SATs) and one 6 m Large Aperture Telescope (LAT). Optimized for minimizing systematic errors in polarization measurements at large angular scales, the SATs will perform a deep, degree-scale survey of 10% of the sky to search for the signature of primordial gravitational waves. The LAT will survey 40% of the sky with arc-minute resolution. These observations will measure (or limit) the sum of neutrino masses, search for light relics, measure the early behavior of Dark Energy, and refine our understanding of the intergalactic medium, clusters and the role of feedback in galaxy formation. With up to ten times the sensitivity and five times the angular resolution of the Planck satellite, and roughly an order of magnitude increase in mapping speed over currently operating (Stage 3) experiments, SO will measure the CMB temperature and polarization fluctuations to exquisite precision in six frequency bands from 27 to 280 GHz. SO will rapidly advance CMB science while informing the design of future observatories such as CMB-S4. Construction of SO-Nominal is fully funded, and operations and data analysis are funded for part of the planned five-year observations. We will seek federal funding to complete the observations and analysis of SO-Nominal, at the $25M level. The SO has a low risk and cost efficient upgrade path the 6 m LAT can accommodate almost twice the baseline number of detectors and the SATs can be duplicated at low cost. We will seek funding at the $75M level for an expansion of the SO (SO-Enhanced) that fills the remaining focal plane in the LAT, adds three SATs, and extends operations by five years, substantially improving our science return. By this time SO may be operating as part of the larger CMB-S4 project. This white paper summarizes and extends material presented in, which describes the science goals of SO-Nominal, and which describe the instrument design.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN74208
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  • 7
    Publication Date: 2019-07-13
    Description: We report a measurement of the power spectrum of cosmic microwave background (CMB) lensing from two seasons of Atacama Cosmology Telescope polarimeter (ACTPol) CMB data. The CMB lensing power spectrum is extracted from both temperature and polarization data using quadratic estimators. We obtain results that are consistent with the expectation from the best-fit Planck CDM model over a range of multipoles L 80-2100, with an amplitude of lensing A(sub lens) = 1.06 +/- 0.15 stat +/- 0.06 sys relative to Planck. Our measurement of the CMB lensing power spectrum gives sigma 8 omega m(sup 0.25) = 0.643 +/- 0.054; including baryon acoustic oscillation scale data, we constrain the amplitude of density fluctuations to be sigma 8 = 0.831 +/- 0.053. We also update constraints on the neutrino mass sum. We verify our lensing measurement with a number of null tests and systematic checks, finding no evidence of significant systematic errors. This measurement relies on a small fraction of the ACTPol data already taken; more precise lensing results can therefore be expected from the full ACTPol data set.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN44620 , Physical Review D (ISSN 1550-7998) (e-ISSN 1089-4918); 95; 12; 123529
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  • 8
    Publication Date: 2019-10-23
    Description: A millimeter-wave survey over half the sky, that spans frequencies in the range of 30 to 350 GHz, and that is both an order of magnitude deeper and of higher-resolution than currently funded surveys would yield an enormous gain in understanding of both fundamental physics and astrophysics. By providing such a deep, high-resolution millimeter-wave survey (about 0.5 Karcmin noise and 15 arcsecond resolution at 150 GHz), CMB-HD will enable major advances.It will allow 1.) the use of gravitational lensing of the primordial microwave background to map the distribution of matter on small scales (k 10 hMpc1), which probes dark matter particle properties. It will also allow 2.) measurements of the thermal and kinetic Sunyaev-Zel'dovich effects on small scales to map the gas density and gas pressure profiles of halos over a wide field,which probes galaxy evolution and cluster astrophysics. In addition, CMB-HD would allow us to cross critical thresholds in fundamental physics: 3.) ruling out or detecting any new, light (〈 0:1 eV), thermal particles, which could potentially be the dark matter, and 4.) testing a wide class of multi-field models that could explain an epoch of inflation in the early Universe. Such a survey would also 5.) monitor the transient sky by mapping the full observing region every few days,which opens a new window on gamma-ray bursts, novae, fast radio bursts, and variable active galactic nuclei. Moreover, CMB-HD would 6.) provide a census of planets, dwarf planets, andasteroids in the outer Solar System, and 7.) enable the detection of exo-Oort clouds around othersolar systems, shedding light on planet formation. The combination of CMB-HD with contemporaryground and space-based experiments will also provide powerful synergies. CMB-HD willdeliver this survey in 5 years of observing 20,000 square degrees, using two new 30-meter-classoff-axis cross-Dragone telescopes to be located at Cerro Toco in the Atacama Desert. The telescopeswill field about 2.4 million detectors (600,000 pixels) in total. The CMB-HD survey willbe made publicly available, with usability and accessibility a priority.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN74211
    Format: application/pdf
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