ALBERT

Description: Reexploring convection and its various transitions to chaotic behavior were the central themes of GFD 1981. Our principal lecturer, Dr. Edward A. Spiegel, provided both a rich historical picture and stimulating hours at the current frontiers of this topic. Before the summer was out his research lecture on "A Tale of Two Methods" elegantly merged Pierre Coullet's canonical formalism for studying dynamical systems in a central manifold and the more traditional two-timing amplitude expansions near critical points. Other lecture sequences on convection and its relation to simpler dynamical systems ranged from the fine presentations of John Guckenheimer on bifurcation theory to Fritz Busse's survey of his immense contributions to our understanding of nonlinear convection. The list of other lectures found on the following pages attests to our summer-long exposure to convection in the ocean, the atmosphere, the earth's core and mantle, and in the sun. August brought lectures on new observations of convection in the laboratories of physicists. Albert Libchaber's precise experiments on the many routes convection can take to turbulence, with parallel laboratory and numerical experiments described by J. Gollub and E. Siggia, added much to our language of inquiry.

Description: Office of Naval Research under Contract N00014-81-G-0089.

Description: NASA Laboratory Astrophysics Workshop 2006, is the fourth in a series of workshops held at four year intervals, to assess the laboratory needs of NASA's astrophysics missions - past, current and future. Investigators who need laboratory data to interpret their observations from space missions, theorists and modelers, experimentalists who produce the data, and scientists who compile databases have an opportunity to exchange ideas and understand each other's needs and limitations. The multi-wavelength character of these workshops allows cross-fertilization of ideas, raises awareness in the scientific community of the rapid advances in other fields, and the challenges it faces in prioritizing its laboratory needs in a tight budget environment. Currently, we are in the golden age of Space Astronomy, with three of NASA s Great Observatories, Hubble Space Telescope (HST), Chandra X-Ray Observatory (CXO), and Spitzer Space Telescope (SST), in operation and providing astronomers and opportunity to perform synergistic observations. In addition, the Far Ultraviolet Spectroscopic Explorer (FUSE), XMM-Newton, HETE-2, Galaxy Evolution Explorer (GALEX), INTEGRAL and Wilkinson Microwave Anisotropy Probe (WMAP), are operating in an extended phase, while Swift and Suzaku are in their prime phase of operations. The wealth of data from these missions is stretching the Laboratory Astrophysics program to its limits. Missions in the future, which also need such data include the James Webb Space Telescope (JWST), Space Interferometry Mission (SIM), Constellation-X (Con-X), Herschel, and Planck. The interpretation of spectroscopic data from these missions requires knowledge of atomic and molecular parameters such as transition probabilities, f-values, oscillator strengths, excitation cross sections, collision strengths, which have either to be measured in the laboratory by simulating space plasma and interactions therein, or by theoretical calculations and modeling. Once the laboratory data are obtained, a key step to making them available to the observer is the creation and maintenance of critically compiled databases. Other areas of study, that are important for understanding planet formation, and for detection of molecules that are indicators of life, are also supported by the Laboratory Astrophysics program. Some examples are: studies of ices and dust grains in a space environment; nature and evolution of interstellar carbon-rich dust; and polycyclic aromatic hydrocarbons. In addition, the program provides an opportunity for the investigation of novel ideas, such as simulating radiative shock instabilities in plasmas, in order to understand jets observed in space. A snapshot of the currently funded program, mission needs, and relevance of laboratory data to interpreting observations, will be obtained at this workshop through invited and contributed talks and poster papers. These will form the basis for discussions in splinter groups. The Science Organization Committee will integrate the results of the discussions into a coherent White Paper, which will provide guidance to NASA in structuring the Laboratory Astrophysics program in subsequent years, and also to the scientific community in submitting research proposals to NASA for funding.

Description: Our universe is most luminous at far-infrared and submillimeter wavelengths (100 GHz - 10 THz) after the Cosmic Microwave Background (CMB) radiation. This region of the electromagnetic spectrum provides critical tracers for the study of a wide range of astrophysical and planetary phenomena. This spectral range contains information on the origin of the planets, stars, galaxies, and clusters; the geometry and matter/energy content of the Universe, atmospheric constituents and dynamics of the planets and comets and tracers for global monitoring and the ultimate health of the Earth. Sensors at far-infrared and submillimeter wavelengths provide unprecedented sensitivity for astrophysical, planetary, and earth observing instruments. Very often, for a spaced based platform where the instruments are not limited by atmospheric losses and absorption, the overall instrument sensitivity is dictated by the sensitivity of the sensors themselves. Moreover, some of the cryogenic sensors at submillimeter wavelengths provide almost quantum-limited sensitivity. This paper provides an overview of the submillimeter-wave sensors and their performance and capabilities for space applications.

Description: Continuum observations at 350 micrometers of seven nearby elliptical galaxies for which CO gas disks have recently been resolved with interferometry mapping are presented. These SHARC II mapping results provide the first clearly resolved far-infrared (FIR)-to-submillimeter continuum emission from cold dust (with temperatures 31 K is approximately greater than T approximately greater than 23 K) of any elliptical galaxy at a distance greater than 40 Mpc. The measured FIR excess shows that the most likely and dominant heating source of this dust is not dilute stellar radiation or cooling flows, but rather star formation that could have been triggered by an accretion or merger event and fueled by dust-rich material that has settled in a dense region cospatial with the central CO gas disks. The dust is detected even in two cluster ellipticals that are deficient in H (sub I), showing that, unlike H (sub I), cold dust and CO in ellipticals can survive in the presence of hot X-ray gas, even in galaxy clusters. No dust cooler than 20 K, either distributed outside the CO disks or cospatial with and heated by the entire dilute stellar optical galaxy (or very extended H (sub I)), is currently evident.

Description: In Kelly, Tichy, Campanelli & Whiting Phys. Rev. D vol. 76, 024008 (2007). we presented nonspinning black-hole binary data for numerical relativity, based on solving the constraint equations to 2.5pN order in an ADM-Transverse-Traceless gauge. Here we report on the first steps in evolving this data in full NR. We review the orbital and waveform characteristics, and how these may be improved in future evolutions.

Description: The large numbers of nucleus fragments observed are a spectacular illustration of the process of cascading fragmentation in progress, a concept introduced to interpret the properties of the Kreutz system of sungrazers and comet D/1993 F2. The objective is to describe the fragmentation sequence and hierarchy of comet 73P, the nature of the fragmentation process and observed events, and the expected future evolution of this comet. The orbital arc populated by the fragments refers to an interval of 3.74 days in the perihelion time. This result suggests that they all could be products (but not necessarily first-generation fragments) of two 1995 events, in early September (involving an enormous outburst) and at the beginning of November. The interval of perihelion times is equivalent to a range of about 2.5 m/s in separation velocity or 0.00012 the Sun's attraction in nongravitational deceleration. Their combined effect suggests minor orbital momentum changes acquired during fragmentation and decelerations compatible with survival over two revolutions about the Sun. Fragment B is a likely first-generation product of one of the 1995 events. From the behavior of the primary fragment C, 73P is not a dying comet, even though fragment B and others were episodically breaking up into many pieces. Each episode began with the sudden appearance of a starlike nucleus condensation and a rapidly expanding outburst, followed by a development of jets, and a gradual tailward extension of the fading condensation, until the discrete masses embedded in it could be resolved. In April-May, this debris traveled first to the southwest, but models show their eventual motion toward the projected orbit. Fainter fragments were imaged over limited time, apparently because of their erratic activity (interspersed with periods of dormancy) rather than improptu disintegration. A dust trail joining the fragments and reminiscent of comet 141P/Machholz suggests that cascading fragmentation exerts itself profoundly over an extremely broad mass range of particulate debris.

Description: The year 2009 was one of transition for the nation, for NASA, and for the Space Studies Board (SSB). The nation pulled back from 2008's economic precipice, but did not return to the path of economic growth that it had been on. The United States inaugurated a new president who set out to build his administration. By mid-year President Obama had announced the appointment of Charlie Bolden as NASA administrator, and Lori Garver as deputy administrator. The president and Charlie Bolden jointly appointed an independent commission, the now well-known Augustine Commission, to provide guidance on the future of NASA's human spaceflight program. Many had known for quite a while that NASA's human spaceflight program faced a profound change at the time of the retirement of the space shuttle. This year was also a year of transition for the SSB. In 2009, Marcia Smith stepped down as staff director for both SSB and ASEB, and Dick Rowberg had a very good turn at the plate as a pinch-hitter. We are deeply indebted to both of them. We are pleased that, after a successful run as study director for Astro2010, Michael Moloney is now director of SSB and ASEB. The profound work begun in 2009 on the decadal surveys will only see the light of day later as they are released and the scientific work begins. The SSB will have much to report for 2010.

Description: The year 2008 was an historic one for both our country and the Space Studies Board (SSB). The United States elected a new president. His first task has been to cope with an economic crisis of historic proportions. In the same year, the United States celebrated the 50th anniversary of its first spaceflight, and the SSB celebrated its 50th anniversary. As we in the space community looked back, we also looked forward. The year 2008 was truly a year of transition, for the country and for the space enterprise. Under Lennard Fisk's continued leadership, the SSB completed its year-long seminar series, Forging the Future of Space Science, which highlighted the accomplishments of space science over the past 50 years and looked ahead to the next 50 years of discoveries that await us. During the first half of the year, events were held in Tallahasse, Florida; Austin, Texas; Paris, France (in conjunction with the Committee on Space Research, which is headquartered here); Boulder, Colorado; and Fairmont, West Virginia. The series culminated in a celebration at the National Air and Space Museum in Washington, D.C., on June 26, .50 years to the day after the SSB was created. At that event, the Board presented its first James A. Van Allen Lectureship to Frank McDonald. The recent economic crisis has made it obvious that the U.S. economy does not stand alone. The global economy is becoming more and more integrated. The space enterprise cannot avoid this trend. In November, the SSB conducted a workshop in conjunction with the Aeronautics and Space Engineering Board entitled 'Future International Space Cooperation and Competition in a Globalizing World'. Its goals were to assess the current state of international cooperation and competition in space and to discuss ways in which new and emerging space powers might be better integrated into the global space community.

Description: A major question in the study of black hole binaries involves our understanding of the accretion geometry when the sources are in the "hard" state, with an X-ray energy spectrum dominated by a hard power-law component and radio emission coming from a steady "compact" jet. Although the common hard state picture is that the accretion disk is truncated, perhaps at hundreds of gravitational radii (Rg) from the black hole, recent results for the recurrent transient GX 339-4 by Miller and coworkers show evidence for disk material very close to the black hole's innermost stable circular orbit. That work studied GX 339-4 at a luminosity of approximately 5% of the Eddington limit (L(sub Edd) and used parameters from a relativistic reflection model and the presence of a thermal component as diagnostics. Here we use similar diagnostics but extend the study to lower luminosities (2.3% and 0.8% L(sub Edd)) using Swift and RXTE observations of GX 339-4. We detect a thermal component with an inner disk temperature of approximately 0.2 keV at 2.3% L (sub Edd). At both luminosities, we detect broad features due to iron K-alpha that are likely related to reflection of hard X-rays off disk material. If these features are broadened by relativistic effects, they indicate that the material resides within 10 Rg, and the measurements are consistent with the disk's inner radius remaining at approximately 4 Rg down to 0.8% L(sub Edd). However, we also discuss an alternative model for the broadening, and we note that the evolution of the thermal component is not entirely consistent with the constant inner radius interpretation. Finally, we discuss the results in terms of recent theoretical work by Liu and co-workers on the possibility that material may condense out of an Advection-Dominated Accretion Flow to maintain an inner optically thick disk.

Description: We showed that the exoplanet HAT-P-7b has an extremely tilted orbit, with a true angle of at least 86 degrees with respect to its parent star's equatorial plane, and a strong possibility of retrograde motion. We also report evidence for an additional planet or companion star. The Rossiter-McLaughlin effect was found to be a blueshift during the first half of the transit and a redshift during the second half, an inversion of the usual pattern, implying that the angle between the sky-projected orbital and stellar angular momentum vectors is 182.5 plus or minus 9.4 degrees. The third body is implicated by excess RV variation of the host star over 2 yr. Some possible explanations for the tilted orbit of HAT-P-7b are a close encounter with another planet, the Kozai effect, and resonant capture by an inward-migrating outer planet.