NASA Hubble Space Telescope Daily Report #5176
HUBBLE SPACE TELESCOPE – Continuing to Collect World Class Science
DAILY REPORT #5176
PERIOD COVERED: 5am September 7 – 5am September 8, 2010 (DOY 250/09:00z-251/09:00z)
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)
HSTARS: (None)
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS GSAcq 04 04
FGS REAcq 11 11
OBAD with Maneuver 04 04
SIGNIFICANT EVENTS: (None)
OBSERVATIONS SCHEDULED:
ACS/WFC 12210
SLACS for the Masses: Extending Strong Lensing to Lower Masses and Smaller Radii
Strong gravitational lensing provides the most accurate possible measurement of mass in the central regions of early-type galaxies (ETGs). We propose to continue the highly productive Sloan Lens ACS (SLACS) Survey for strong gravitational lens galaxies by observing a substantial fraction of 135 new ETG gravitational-lens candidates with HST-ACS WFC F814W Snapshot imaging. The proposed target sample has been selected from the seventh and final data release of the Sloan Digital Sky Survey, and is designed to complement the distribution of previously confirmed SLACS lenses in lens-galaxy mass and in the ratio of Einstein radius to optical half-light radius. The observations we propose will lead to a combined SLACS sample covering nearly two decades in mass, with dense mapping of enclosed mass as a function of radius out to the half-light radius and beyond. With this longer mass baseline, we will extend our lensing and dynamical analysis of the mass structure and scaling relations of ETGs to galaxies of significantly lower mass, and directly test for a transition in structural and dark-matter content trends at intermediate galaxy mass. The broader mass coverage will also enable us to make a direct connection to the structure of well-studied nearby ETGs as deduced from dynamical modeling of their line-of-sight velocity distribution fields. Finally, the combined sample will allow a more conclusive test of the current SLACS result that the intrinsic scatter in ETG mass-density structure is not significantly correlated with any other galaxy observables. The final SLACS sample at the conclusion of this program will comprise approximately 130 lenses with known foreground and background redshifts, and is likely to be the largest confirmed sample of strong-lens galaxies for many years to come.
COS/FUV 11686
The Cosmological Impact of AGN Outflows: Measuring Absolute Abundances and Kinetic Luminosities
AGN outflows are increasingly invoked as a major contributor to the formation and evolution of supermassive black holes, their host galaxies, the surrounding IGM, and cluster cooling flows. Our HST/COS proposal will determine reliable absolute chemical abundances in six AGN outflows, which influences several of the processes mentioned above. To date there is only one such determination, done by our team on Mrk 279 using 16 HST/STIS orbits and 100 ksec of FUSE time. The advent of COS and its high sensitivity allows us to choose among fainter objects at redshifts high enough to preclude the need for FUSE. This will allow us to determine the absolute abundances for six AGN (all fainter than Mrk 279) using only 40 HST COS orbits. This will put abundances studies in AGN on a firm footing, an elusive goal for the past four decades. In addition, prior FUSE observations of four of these targets indicate that it is probable that the COS observations will detect troughs from excited levels of C III. These will allow us to measure the distances of the outflows and thereby determine their kinetic luminosity, a major goal in AGN feedback research.
We will use our state of the art column density extraction methods and velocity-dependent photoionization models to determine the abundances and kinetic luminosity. Previous AGN outflow projects suffered from the constraints of deciding what science we could do using ONE of the handful of bright targets that were observable. With COS we can choose the best sample for our experiment. As an added bonus, most of the spectral range of our targets has not been observed previously, greatly increasing the discovery phase space.
COS/NUV/ACS/WFC/FUV 11658
Probing the Outer Regions of M31 with QSO Absorption Lines
We propose HST-COS spectroscopy of 10 quasars behind M31. Absorption lines due to MgII, FeII, CIV, and a variety of other lines will be searched for and measured. Six quasars lie between 1 and 4.2 Holmberg radii near the major axis on the southwest side, where confusion with Milky Way gas is minimized. Two lie even farther out on the southwest side of the major axis. One lies within 1 Holmberg radius. Two of the 10 pass through M31’s high velocity clouds seen in a detailed 21 cm emission map. Exposure time estimates were based on SDSS magnitudes and available GALEX magnitudes. Thus, using the most well-studied external spiral galaxy in the sky, our observations will permit us to check, better than ever before, the standard picture that quasar metal-line absorption systems such as MgII and CIV arise in an extended gaseous halo/disk of a galaxy well beyond its observable optical radius. The observations will yield insights into the nature of the gas and its connection to the very extended stellar components of M31 that have recently been studied. Notably the observations have the potential of extending M31’s rotation curve to very large galactocentric distances, thereby placing new constraints on M31’s dark matter halo.
Finally, we also request that the coordinated parallel orbits be allocated to this program so that we may image the resolved stellar content of M31’s halo and outer disk.
COS/NUV/FUV 11741
Probing Warm-Hot Intergalactic Gas at 0.5 < z < 1.3 with a Blind Survey for O VI, Ne VIII, Mg X, and Si XII Absorption Systems Currently we can only account for half of the baryons (or less) expected to be found in the nearby universe based on D/H and CMB observations. This “missing baryons problem” is one of the highest-priority challenges in observational extragalatic astronomy. Cosmological simulations suggest that the baryons are hidden in low-density, shock-heated intergalactic gas in the log T = 5 – 7 range, but intensive UV and X-ray surveys using O VI, O VII, and O VIII absorption lines have not yet confirmed this prediction. We propose to use COS to carry out a sensitive survey for Ne VIII and Mg X absorption in the spectra of nine QSOs at z(QSO) > 0.89. For the three highest-redshift QSOs, we will also search for Si XII. This survey will provide more robust constraints on the quantity of baryons in warm-hot intergalactic gas at 0.5 < z < 1.3, and the data will provide rich constraints on the metal enrichment, physical conditions, and nature of a wide variety of QSO absorbers in addition to the warm-hot systems. By comparing the results to other surveys at lower redshifts (with STIS, FUSE, and from the COS GTO programs), the project will also enable the first study of how these absorbers evolve with redshift at z < 1. By combining the program with follow-up galaxy redshift surveys, we will also push the study of galaxy-absorber relationships to higher redshifts, with an emphasis on the distribution of the WHIM with respect to the large-scale matter distribution of the universe. STIS/CCD 11845 CCD Dark Monitor Part 2 Monitor the darks for the STIS CCD. STIS/CCD 11847 CCD Bias Monitor-Part 2 Monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns. STIS/CCD 11849 STIS CCD Hot Pixel Annealing This purpose of this activity is to repair radiation induced hot pixel damage to the STIS CCD by warming the CCD to the ambient instrument temperature and annealing radiation-damaged pixels. Radiation damage creates hot pixels in the STIS CCD Detector. Many of these hot pixels can be repaired by warming the CCD from its normal operating temperature near -83 deg. C to the ambient instrument temperature (~ +5 deg. C) for several hours. The number of hot pixels repaired is a function of annealing temperature. The effectiveness of the CCD hot pixel annealing process is assessed by measuring the dark current behavior before and after annealing and by searching for any window contamination effects. STIS/MA2 11862 MAMA NUV Flats This program will obtain NUV-MAMA observations of the STIS internal Deuterium lamp to construct an NUV flat applicable to all NUV modes. WFC3/IR 11696 Infrared Survey of Star Formation Across Cosmic Time We propose to use the unique power of WFC3 slitless spectroscopy to measure the evolution of cosmic star formation from the end of the reionization epoch at z>6 to the close of the galaxy-building era at z~0.3.Pure parallel observations with the grisms have proven to be efficient for identifying line emission from galaxies across a broad range of redshifts. The G102 grism on WFC3 was designed to extend this capability to search for Ly-alpha emission from the first galaxies. Using up to 250 orbits of pure parallel WFC3 spectroscopy, we will observe about 40 deep (4-5 orbit) fields with the combination of G102 and G141, and about 20 shallow (2-3 orbit) fields with G141 alone.
Our primary science goals at the highest redshifts are: (1) Detect Lya in ~100 galaxies with z>5.6 and measure the evolution of the Lya luminosity function, independent of of cosmic variance; 2) Determine the connection between emission line selected and continuum-break selected galaxies at these high redshifts, and 3) Search for the proposed signature of neutral hydrogen absorption at re-ionization. At intermediate redshifts we will (4) Detect more than 1000 galaxies in Halpha at 0.5
