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: http://www.stsci.edu/~inr/thisweek1/thisweek72.html
Дата изменения: Fri Jun 8 23:36:03 2007 Дата индексирования: Tue Oct 2 12:59:43 2012 Кодировка: Поисковые слова: saturn's moon |
| Program number | |
Links | |
| 10114 | Edward Guinan, Villanova University | Lyman_alpha FUV observations of the Sun in time and effects on planetary atmospheres
| Abstract |
| 10166 | William Borucki, NASA Ames Research Center | ACS and WFPC2 Stellar Photometry in the Kepler Mission Target Field
| Abstract |
| 10468 | Erich Karkoschka, University of Arizona | Jupiter's Upper Stratospheric Hazes Probed with Ganymede
| Abstract |
| 10494 | Leon Koopmans, Kapteyn Institute | Imaging the mass structure of distant lens galaxies
| Abstract |
| 10496 | Saul Perlmutter, Lawrence Berkeley National Laboratory | Decelerating and Dustfree: Efficient Dark Energy Studies with Supernovae and Clusters
| Abstract |
| 10524 | Francesco Ferraro, Universita di Bologna | Blue Stragglers: a key stellar population to probe internal cluster dynamics
| Abstract |
| 10532 | Kai Noeske, University of California - Santa Cruz | Kinematics and morphology of the most massive field disk galaxies at z>1
| Abstract |
| 10547 | Edward Fitzpatrick, Villanova University | A SNAP Program to Obtain Complete Wavelength Coverage of Interstellar Extinction
| Abstract |
| 10556 | David Turnshek, UUniversity of Pittsburgh | Neutral Gas at Redshift z=0.5
| Abstract |
| 10587 | Adam Bolton, Smithsonian Institution Astrophysical Observatory | Measuring the Mass Dependence of Early-Type Galaxy Structure
| Abstract |
| 10588 | Michael Brotherton, University of Wyoming | The Host Galaxies of Post-Starburst Quasars
| Abstract |
| 10592 | Aaron Evans, State University of New York at Stony Brook | An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in the Local Universe
| Abstract |
| 10599 | Paul Kalas, University of California - Berkeley | Multi-color imaging of two 1 Gyr old debris disks within 20 pc of the Sun: Astrophysical mirrors of our Kuiper Belt
| Abstract |
| 10603 | Deborah Padgett, Jet Propulsion Laboratory | Multiwavelength Imaging of Edge-on Protoplanetary Disks: Quantifying the Growth of Circumstellar Dust
| Abstract |
| 10605 | Evan Skillman, University of Minnesota - Twin Cities | Quantifying Star Formation and Feedback: The M81 Group Dwarf Galaxies
| Abstract |
| 10606 | Ultraviolet Snapshots of 3CR Radio Galaxies | William Sparks, Space Telescope Science Institute
| Abstract |
| 10610 | George Benedict, University of Texas at Austin | Astrometric Masses of Extrasolar Planets and Brown Dwarfs
| Abstract |
| 10627 | Margaret Meixner, Space Telescope Science Institute | A Snapshot Survey of Post-AGB Objects and Proto-Planetary Nebulae
| Abstract |
| 10717 | Zhaohui Shang, University of Wyoming | Quasar Bolometric Luminosity and Spectral Energy Distributions from Radio to X-ray
| Abstract |
| 10775 | Ata Sarajedini, University of Florida | An ACS Survey of Galactic Globular Clusters
| Abstract |
| 10781 | Young-Jun Choi, Jet Propulsion Laboratory | Observations of the active Centaur 60558 2000 EC98
| Abstract |
HST image of Jupiter |
Over the next week, ACS will take a series of images of Ganymede, catching the satellite as it slips into occultation behind Jupiter. The observations, in five different passbands spanning the ultraviolet (250 nm) to the far red (892 nm), will probe the upper layers of the parent planet's atmosphere, and permit investigation of the structure of haze within the Jovian stratosphere. Until now, studies of the creation, growth and motions of these layers has been limited to theoretical analyses; the ACS/HRC images will provide the first empirical measurements of the aerosols responsible for the high haze. |
Dark energy and the accelerating universe |
The last few years of the twentieth century saw a revolution in cosmology, with the measurement of the acceleration term in expansion at high redshifts and the identification of dark energy as a major cosmological component. Type Ia supernovae are the prime yardstick for measuring the rate of expansion at moderate and high redshifts, but applying appropriate corrections for in situ reddening by dust remains an issue. The present program aims to minimise the uncertainties by searching for supernovae in massive, high-redshift clusters, with the expectation that the majority of detections lie within dust-poor elliptical galaxies. ACS survey observations of eight clusters are scheduled for the coming week, together with follow-up NICMOS observations of a supernova detected in previous ACS images. |
A NICMOS image of the interacting LIRG, NGC 6090 |
Luminous infrared galaxies (LIRGs) have total luminosities that exceed
1011.4 LSun, with most of the energy emitted at wavelengths longward
of 10 microns. Many (perhaps most) of these galaxies are interacting or merging disk
galaxies, with the excess infrared luminosity generated by warm dust associated with
the extensive star formation regions. Many systems also exhibit an active nucleus, and
may be in the process of evolving towards an S0 or elliptical merger remnant. The
present program surveys a total of 88 such systems from the IRAS Revised Bright Galaxy
Sample, imaging each system with the ACS using the F439W (B) and F814W (I) filters. The
observations will probe
|
An artist's impression of the planets circling the M dwarf, Gl 876 |
The overwhelming majority of extrasolar planetary systems have been identified through radial velocity monitoring, and the detection of the reflex motion of the parent star as it orbits the common center of mass of the system. Just as radial velocities measure the stellar "wobble" introduced along the line of sight, so high precision astrometry can be used to measure motion in the plane of the sky. Combining these data gives the full three-dimensional motions of the system, and a direct measure of the mass of the planetary companion. The Fine Guidance Sensors on HST are the only system currently capable of making observations at the required sub-milliarcscond accuracy, and has already been used for astrometry of four systems, including the M dwarf Gl 876. The current GO program pursues observations of six planetary hosts, and FGS observations of three targets, HD 136118, HD 145675 (14 Her) and HD 168443, are scheduled over the next week. |
HST image of the globular cluster M15 |
Globular clusters are members of the Galactic halo population, which formed
during the first extensive period of star formation in the Milky Way. As such, the
properties of the 106 to 107 stellar constituents can provide crucial
insight into the earliest stages of galaxy formation. The present HST program will
obtain two-colour (F606W, F814W) ACS images of the central regions of 66 of the ~150 Galactic clusters, with
the goals of
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