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Daily # 4275
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 4275 PERIOD COVERED: UT January 09, 2007 (DOY 009) OBSERVATIONS SCHEDULED NIC1/NIC2/NIC3 8794 NICMOS Post-SAA calibration - CR Persistence Part 5 A new procedure proposed to alleviate the CR-persistence problem of NICMOS. Dark frames will be obtained immediately upon exiting the SAA contour 23, and every time a NICMOS exposure is scheduled within 50 minutes of coming out of the SAA. The darks will be obtained in parallel in all three NICMOS Cameras. The POST-SAA darks will be non-standard reference files available to users with a USEAFTER date/time mark. The keyword 'USEAFTER=date/time' will also be added to the header of each POST-SAA DARK frame. The keyword must be populated with the time, in addition to the date, because HST crosses the SAA ~8 times per day so each POST-SAA DARK will need to have the appropriate time specified, for users to identify the ones they need. Both the raw and processed images will be archived as POST-SAA DARKSs. Generally we expect that all NICMOS science/calibration observations started within 50 minutes of leaving an SAA will need such maps to remove the CR persistence from the science images. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors. NIC2, ACS/WFC 10802 SHOES-Supernovae, HO, for the Equation of State of Dark energy The present uncertainty in the value of the Hubble constant {resulting in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at redshifts exceeding 1 are now the leading obstacles to determining the nature of dark energy. We propose a single, integrated set of observations for Cycle 15 that will provide a 40% improvement in constraints on dark energy. This program will observe known Cepheids in six reliable hosts of Type Ia supernovae with NICMOS, reducing the uncertainty in H_0 by a factor of two because of the smaller dispersion along the instability strip, the diminished extinction, and the weaker metallicity dependence in the infrared. In parallel with ACS, at the same time the NICMOS observations are underway, we will discover and follow a sample of Type Ia supernovae at z 1. Together, these measurements, along with prior constraints from WMAP, will provide a great improvement in HST's ability to distinguish between a static, cosmological constant and dynamical dark energy. The Hubble Space Telescope is the only instrument in the world that can make these IR measurements of Cepheids beyond the Local Group, and it is the only telescope in the world that can be used to find and follow supernovae at z 1. Our program exploits both of these unique capabilities of HST to learn more about one of the greatest mysteries in science. NIC3 10861 An ACS Treasury Survey of the Coma cluster of galaxies We propose to use the unique spatial resolution of HST and ACS to construct a Treasury imaging survey of the core and infall region of the richest local cluster, Coma. We will observe samples of thousands of galaxies down to magnitude B=27.3 with the aim of studying in detail the dwarf galaxy population which, according to hierarchical models of galaxy formation, are the earliest galaxies to form in the universe. Our initial scientific objectives a 1} A study of the structure of the dwarf galaxies, including scaling laws, nuclear structure and morphology, to compare with hierarchical and evolutionary models of their formation. 2} A study of the stellar populations from colors and color gradients, and how the internal chemical evolution of galaxies is affected by interaction with the cluster gaseous and galaxy environment. 3} To determine the effect of the cluster environment upon morphological features, disks, bulges and bars, by comparing these structure in the Coma sample with field galaxy samples. 4} Identification of dwarf galaxy samples for further study with the new generation of multi-object and integral-field spectrographs on 8-10 metre class telescopes such as Keck, Subaru, Gemini, and GTC. This is the first such survey of a nearby rich cluster. It will provide a key database for studies of galaxy formation and evolution, and a very needed reference for comparison with similar galaxy surveys both in lower density environments in the nearby universe, and in high density environments at high redshifts. NIC3 10874 Search for Extremely Faint z7 Galaxy Population with Cosmic Lenses Deep UDF/NICMOS observations find a significant decrease in the number of galaxy candidates between redshift z=6 and 7, but the sample at z7 is too small to draw conclusions. From our observations of 15 clusters we have found a number of bright z-dropouts, aided by the lensing amplification. We propose deep NICMOS observations of the best cases of cluster centers where a rare combination of a significant lensing effect and the richness in z-band dropouts in background may dramatically increase the discovery rate. The NICMOS images will reach an unprecendented depth of AB~27.8, or AB~30 in nonlensed intrinsic magnitude, and may find many faint {~0.05L*} galaxies at z=7-10, at a level that the UDF reaches for z~6 objects. We produce precision mass distribution maps from weak-lensing models, which enable us to derive the candidates' intrinsic magnitudes and their luminosity function. The knowledge of such faint galaxy population at z7 will facilitate the models of the IGM reionization and future JWST planning. WFPC2 10915 ACS Nearby Galaxy Survey Existing HST observations of nearby galaxies comprise a sparse and highly non-uniform archive, making comprehensive comparative studies among galaxies essentially impossible. We propose to secure HST's lasting impact on the study of nearby galaxies by undertaking a systematic, complete, and carefully crafted imaging survey of ALL galaxies in the Local Universe outside the Local Group. The resulting images will allow unprecedented measurements of: {1} the star formation history {SFH} of a 100 Mpc^3 volume of the Universe with a time resolution of Delta[log{t}]=0.25; {2} correlations between spatially resolved SFHs and environment; {3} the structure and properties of thick disks and stellar halos; and {4} the color distributions, sizes, and specific frequencies of globular and disk clusters as a function of galaxy mass and environment. To reach these goals, we will use a combination of wide-field tiling and pointed deep imaging to obtain uniform data on all 72 galaxies within a volume-limited sample extending to ~3.5 Mpc, with an extension to the M81 group. For each galaxy, the wide-field imaging will cover out to ~1.5 times the optical radius and will reach photometric depths of at least 2 magnitudes below the tip of the red giant branch throughout the limits of the survey volume. One additional deep pointing per galaxy will reach SNR~10 for red clump stars, sufficient to recover the ancient SFH from the color-magnitude diagram. This proposal will produce photometric information for ~100 million stars {comparable to the number in the SDSS survey} and uniform multi-color images of half a square degree of sky. The resulting archive will establish the fundamental optical database for nearby galaxies, in preparation for the shift of high-resolution imaging to the near-infrared. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: 10611 - GSacq(2,1,2) failed due to search radius limit exceeded GSacq(2,1,2) scheduled at 009/22:45:10 failed at 22:48:38 due to search radius limit exceeded on FGS 1. OBAD2 showed errors of V1=-3.57, V2=-17.96, V3= -5.75 and RSS= 19.19. OBAD1 data is not available due to LOS. The Reacq(2,1,2) scheduled at 00:11:16 also failed due to search radius limit exceeded on FGS 1. OBAd data was unavailable due to LOS. REacq(2,1,2) scheduled at 01:50:22 failed due to search radius limit exceeded on FGS 1. OBAD1 showed errors of V1=-72.51, V2=-1833.26, V3=-38.72, RSS=1835.10. OBAD2 showed errors of V1=-3.92, V2=1.35, V3=-9.51, RSS=10.38. Upon acquisition of signal at 010/04:18:51, subsequent REacq(2,1,2) scheduled at 010/03:28:35 had failed to RGA Hold (Gyro Control) due to search radius limit exceeded on FGS 1. Pre-acquisition OBADs data not available due to LOS. COMPLETED OPS REQUEST: (None) COMPLETED OPS NOTES: (None) SCHEDULED SUCCESSFUL FGS GSacq 07 06 FGS REacq 08 05 OBAD with Maneuver 30 30 SIGNIFICANT EVENTS: (None) |
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