NASA Hubble Space Telescope Daily Report # 4508
HUBBLE SPACE TELESCOPE DAILY REPORT # 4508
– Continuing to collect World Class Science
PERIOD COVERED: UT December 14,15,16, 2007 (DOY 348,349,350)
OBSERVATIONS SCHEDULED
NIC1/NIC2/NIC3 8795
NICMOS Post-SAA calibration – CR Persistence Part 6
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=3Ddate/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 i mages. Each observation will need its own CRMAP, as different SAA passages leave different imprints on the NICMOS detectors.
FGS 11462
FGS1r, FGS2r, and FGS3 Pre-SM4 Performance
This proposal is the first of a pair of proposals that monitors the characteristics of HST’s two ” continuing” Fine Guidance Sensors across the boundary of the servicing mission SM4. This proposal obtains the pre-SM4 measurements. Proposal 11463 gathers the same data but for the post-SM4 baseline. For each FGS, stars from a selected field in the standard astrometric Galactic cluster M35 are observed in Position mode. This provides a measurement of their relative positions, which in turn provides an effective means to detect and monitor any changes in the FGS optical distortions and plate scales. If out of tolerance, the need for a re- calibration of the particular FGS’s distortions will be indicated. The FGS-FGS alignments will also be monitored across the SM boundary. This will be done by using the same guide star pairs in the corrresponding proposal 11463. Finally, this proposal and 11463 include Transfer mode observations of selected M35 stars. These observations will obtain S-curves at the center and at two off-center field points in each FGS FOV. These data will provide insight as to whether or not the relative alignment of the FGS optical train with the HST OTA has changed. If changes larger than tolerance are observed, it will be necessary to activate the appropriate contingency proposal that will obtain S-curves are several locations in the FGS FOV to facilitate a re-computation of the optimal values of K-factors that are used in the acquisition and tracking of guide stars (and astrometry targets). This proposal requires a total of 4 HST orbit to support the FGS2r and FGS3 observations. The FGS1r observations are available from the FGS Cycle 16 Astrometry calibration plan.
FGS 11315
Monitoring FGS1r’s Interferometric Response as a Function of Spectral Color
This proposal uses FGS1r in Transfer mode to observe single stars to obtain the interference fringes of point sources. These data are used by FGS data analysis tools for studying binary and hierarchical multiple star systems. Visit 01 observes three stars in M35 over the FGS1r FOV as a precursor to a corresponding visit in FGS/SM4 proposal 11463.
NIC3 11306
Direct radius measurement of the Neptune-size transiting exoplanet GJ436b
We propose to measure the radius of the first transiting Neptune-class extrasolar planet, GJ 436b. The transits of this 22-Earth-mass planet around a nearby M dwarf were recently detected by our team. Ground-based photometric observations indicate a planet size compatible with a Neptune-like structure or an “Ocean Planet”. A direct radius determination from an HST infrared lightcurve will provide a much more direct measurement of the radius and density of the planet. GJ 436b is the nearest known transiting exoplanet, as well as the smallest and lightest, by a large margin. The high planet-to-star contrast in the infrared make it very favorable for detailed studies. NICMOS 1-2 microns observations, in addition to measuring its size, may reveal water absorption from its outer atmosphere.
ACS/SBC 11215
New Sightlines for the Study of Intergalactic Helium: Dozens of High-Confidence, UV-Bright Quasars from SDSS/GALEX
The reionization of IGM helium is thought to have occurred at redshifts of z=3D3 to 4. Detailed study of HeII Lyman-alpha absorption toward a handful of QSOs at 2.7 FGS 11213 Distances to Eclipsing M Dwarf Binaries We propose HST FGS observations to measure accurate distances of 5 nearby M dwarf eclipsing binary systems, from which model-independent luminosities can be calculated. These objects have either poor or no existing parallax measurements. FGS parallax determinations for these systems, with their existing dynamic masses determined to better than 0.5%, would serve as model-independent anchor points for the low-mass end of the mass-luminosity diagram. FGS 11211 An Astrometric Calibration of Population II Distance Indicators In 2002 HST produced a highly precise parallax for RR Lyrae. That measurement resulted in an absolute magnitude, M{V}=3D 0.61+/-0.11, a useful result, judged by the over ten refereed citations each year since. It is, however, unsatisfactory to have the direct, parallax-based, distance scale of Population II variables based on a single star. We propose, therefore, to obtain the parallaxes of four additional RR Lyrae stars and two Population II Cepheids, or W Vir stars. The Population II Cepheids lie with the RR Lyrae stars on a common K-band Period-Luminosity relation. Using these parallaxes to inform that relationship, we anticipate a zero-point error of 0.04 magnitude. This result should greatly strengthen confidence in the Population II distance scale and increase our understanding of RR Lyrae star and Pop II Cepheid astrophysics. WFPC2/NIC2 11193 A comprehensive study of the low-mass stellar population in the Galactic starburst region NGC 3603 NGC 3603, located in the Carina spiral arm, is one of the most luminous giant HII regions in the Milky Way, and as such it is often referred to as a prime template for extragalactic starbursts. While previous studies were focusing on the high and intermediate mass stellar content of the central starburst cluster, which powers the HII region, the effects of the starburst environment with its large number of ionizing O stars on the emerging low-mass population are unknown. As the most nearby, most easily accessible starburst, NGC 3603 provides the best testbed to study the long-lived, low-mass stars originating from a starburst environment. Taking advantage of the large field of view and high sensitivity of WFPC2, we want to survey the stellar population in an area of 10pc x 10pc {6′ x 6′} down to a mass limit of 0.2 to 0.5 Mo. This will enable us to derive the total cluster mass, look for spatial variations in the initial mass function, determine the age of the dispersed low-mass population in the HII region and search for evidence of sequential star formation. Ultimately, we aim at reconstructing the low-mass stellar initial mass function of the starburst epoch in NGC 3603, which in turn will advance our understanding of extragalactic starburst phenomena and the emerging low-mass stars as observed in ancient populations. The observations of NGC 3603 are part of our larger effort to study intense star-forming regions in the Milky Way, LMC and SMC. WFPC2 11178 Probing Solar System History with Orbits, Masses, and Colors of Transneptunian Binaries The recent discovery of numerous transneptunian binaries {TNBs} opens a window into dynamical conditions in the protoplanetary disk where they formed as well as the history of subsequent events which sculpted the outer Solar System and emplaced them onto their present day heliocentric orbits. To date, at least 47 TNBs have been discovered, but only about a dozen have had their mutual orbits and separate colors determined, frustrating their use to investigate numerous important scientific questions. The current shortage of data especially cripples scientific investigations requiring statistical comparisons among the ensemble characteristics. We propose to obtain sufficient astrometry and photometry of 23 TNBs to compute their mutual orbits and system masses and to determine separate primary and secondary colors, roughly tripling the sample for which this information is known, as well as extending it to include systems of two near-equal size bodies. To make the most efficient possible use of HST, we will use a Monte Carlo technique to optimally schedule our observations. NIC3 11107 Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy Formation in the Early Universe We have used the ultraviolet all-sky imaging survey currently being conducted by the Galaxy Evolution Explorer {GALEX} to identify for the first time a rare population of low- redshift starbursts with properties remarkably similar to high-redshift Lyman Break Galaxies {LBGs}. These “compact UV luminous galaxies” {UVLGs} resemble LBGs in terms of size, SFR, surface brightness, mass, metallicity, kinematics, dust, and color. The UVLG sample offers the unique opportunity of investigating some very important properties of LBGs that have remained virtually inaccessible at high redshift: their morphology and the mechanism that drives their star formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS in order to 1} characterize their morphology and look for signs of interactions and mergers, and 2} probe their star formation histories over a variety of timescales. The images show a striking trend of small-scale mergers turning large amounts of gas into vigorous starbursts {a process referred to as dissipational or “wet” merging}. Here, we propose to complete our sample of 31 LBG analogs using the ACS/SBC F150LP {FUV} and WFPC2 F606W {R} filters in order to create a statistical sample to study the mechanism that triggers star formation in UVLGs and its implications for the nature of LBGs. Specifically, we will 1} study the trend between galaxy merging and SFR in UVLGs, 2} artificially redshift the FUV images to z=3D1-4 and compare morphologies with those in similarly sized samples of LBGs at the same rest-frame wavelengths in e.g. GOODS, UDF, and COSMOS, 3} determine the presence and morphology of significant stellar mass in “pre-burst” stars, and 4} study their immediate environment. Together with our Spitzer {IRAC+MIPS}, GALEX, SDSS and radio data, the HST observations will form a unique union of data that may for the first time shed light on how the earliest major episodes of star formation in high redshift galaxies came about. This proposal was adapted from an ACS HRC+WFC proposal to meet the new Cycle 16 observing constraints, and can be carried out using the ACS/SBC and WFPC2 without compromising our original science goals. NIC3 11082 NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured Universe (uses ACS/SBC and WFPC2) Deep near-infrared imaging provides the only avenue towards understanding a host of astrophysical problems, including: finding galaxies and AGN at z > 7, the evolution of the most massive galaxies, the triggering of star formation in dusty galaxies, and revealing properties of obscured AGN. As such, we propose to observe 60 selected areas of the GOODS North and South fields with NICMOS Camera 3 in the F160W band pointed at known massive M > 10^11 M_0 galaxies at z > 2 discovered through deep Spitzer imaging. The depth we will reach {26.5 AB at 5 sigma} in H_160 allows us to study the internal properties of these galaxies, including their sizes and morphologies, and to understand how scaling relations such as the Kormendy relationship evolved. Although NIC3 is out of focus and undersampled, it is currently our best opportunity to study these galaxies, while also sampling enough area to perform a general NIR survey 1/3 the size of an ACS GOODS field. These data will be a significant resource, invaluable for many other science goals, including discovering high redshift galaxies at z > 7, the evolution of galaxies onto the Hubble sequence, as well as examining obscured AGN and dusty star formation at z > 1.5. The GOODS fields are the natural location for HST to perform a deep NICMOS imaging program, as extensive data from space and ground based observatories such as Chandra, GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT, and the VLA are currently available for these regions. Deep high-resolution near-infrared observations are the one missing ingredient to this survey, filling in an important gap to create the deepest, largest, and most uniform data set for studying the faint and distant universe. The importance of these images will increase with time as new facilities come on line, most notably WFC3 and ALMA, and for the planning of future JWST observations. NIC3 11080 Exploring the Scaling Laws of Star Formation As a variety of surveys of the local and distant Universe are approaching a full census of galaxy populations, our attention needs to turn towards understanding and quantifying the physical mechanisms that trigger and regulate the large-scale star formation rates {SFRs} in galaxies. WFPC2 11037 Red Filters Closeout This calibration program observes three very red stars {M, L, T dwarfs} in the five reddest broad and medium filters {F785LP, F791W, F814W, F850LP, and F1042M} on WF3 in order to allow cross-calibration to ACS, and in future WFC3. The far-red QE curves will also be tested. Similar observations on PC1 were made in WFPC2/CAL 10078 and 10366. WFPC2 11022 WFPC2 Cycle 15 Decontaminations and Associated Observations This proposal is for the WFPC2 decons. Also included are instrument monitors tied to decons: photometric stability check, focus monitor, pre- and post-decon internals {bias, intflats, kspots, & darks}, UV throughput check, VISFLAT sweep, and internal UV flat check. WFPC2 11020 Cycle 15 Focus Monitor The focus of HST is measured primarily with ACS/HRC over full CVZ orbits to obtain accurate mean focus values via a well sampled breathing curve. Coma and astigmatism are also determined from the same data in order to further understand orbital effects on image quality and optical alignments. To monitor the stability of ACS to WFPC2 relative focii, we’ve carried over from previous focus monitor programs parallel observations taken with the two cameras at suitable orientations of previously observed targets, and interspersed them with the HRC CVZ visits. FGS 10928 Calibrating Cosmological Chronometers: White Dwarf Masses We propose to use HST/FGS1R to determine White Dwarf {WD} masses. The unmatched resolving power of HST/FGS1R will be utilized to follow up four selected WD binary pairs. This high precision obtained with HST/FGS1R simply cannot be equaled by any ground based technique. This proposed effort complements that done by CoI Nelan in which a sample of WDs is being observed with HST/FGS1R. This proposal will dramatically increase the number of WDs for which dynamical mass measurements are possible, enabling a better calibration of the WD mass-radius relation, cooling curves, initial to final mass relations, and ultimately giving important clues to the star formation history of our Galaxy and the age of its disk as well as in other galaxies. 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}]=3D0.25; {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. WFPC2 10877 A Snapshot Survey of the Sites of Recent, Nearby Supernovae During the past few years, robotic {or nearly robotic} searches for supernovae {SNe}, most notably our Lick Observatory Supernova Search {LOSS}, have found hundreds of SNe, many of them in quite nearby galaxies {cz < 4000 km/s}. Most of the objects were discovered before maximum brightness, and have follow-up photometry and spectroscopy; they include some of the best-studied SNe to date. We propose to conduct a snapshot imaging survey of the sites of some of these nearby objects, to obtain late-time photometry that {through the shape of the light and color curves} will help reveal the origin of their lingering energy. The images will also provide high-resolution information on the local environments of SNe that are far superior to what we can procure from the ground. For example, we will obtain color-color and color-magnitude diagrams of stars in these SN sites, to determine the SN progenitor masses and constraints on the reddening. Recovery of the SNe in the new HST images will also allow us to actually pinpoint their progenitor stars in cases where pre- explosion images exist in the HST archive. This proposal is an extension of our successful Cycle 13 snapshot survey with ACS. It is complementary to our Cycle 15 archival proposal, which is a continuation of our long-standing program to use existing HST images to glean information about SN environments. NIC3 10874 Search for Extremely Faint z>7 Galaxy Population with Cosmic Lenses Deep UDF/NICMOS observations find a significant decrease in the number of galaxy candidates between redshift z=3D6 and 7, but the sample at z>7 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=3D7-10, 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 z>7 will facilitate the models of the IGM reionization and future JWST planning. ACS/SBC 10872 Lyman Continuum Emission in Galaxies at z=3D1.2 Lyman continuum photons produced in massive starbursts may have played a dominant role in the reionization of the Universe. Starbursts are important contributors to the ionizing metagalactic background at lower redshifts as well. However, their contribution to the background depends upon the fraction of ionizing radiation that escapes from the intrinsic opacity of galaxies below the Lyman limit. Current surveys suggest escape fractions of a few percent, up to 10%, with very few detections {as opposed to upper limits} having been reported. No detections have been reported in the epochs between z=3D0.1 and z=3D2. We propose to = measure the fraction of escaping Lyman continuum radiation from 15 luminous z~1.2 galaxies in the GOODS fields. Using the tremendous sensitivity of the ACS Solar- blind Channel, we will reach AB=3D30 mag., allowing us to detect an escape fraction of 1%. We will correlate the amount of escaping radiation with the photometric and morphological properties of the galaxies. A non-detection in all sources would imply that QSOs provide the overwhelming majority of ionizing radiation at z=3D1.3, and = it would strongly indicate that the properties of galaxies at higher redshift have to be significantly different for galaxies to dominate reionization. The deep FUV images will also be useful for extending the FUV study of other galaxies in the GOODS fields. WFPC2 10812 Space Motions for the Draco and Sextans Dwarf Spheroidal Galaxies We will use the powerful astrometric capabilities of HST to measure proper motions for the Draco and Sextans dwarf spheroidal galaxies that will yield tangential velocities accurate to about 30 km/s. These two galaxies are the last inside a galactocentric radius of 200~kpc without measured proper motions. Knowing their orbits is critical for our understanding of the low-luminosity satellites of the Milky Way. In particular they are critical for understanding why Ursa Minor has survived tidal disruption on its plunging orbit and how Carina formed a large intermediate-age stellar population despite its small mass. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: 11100 – REACQ(2,1,2) fine lock backup on FGS 2 REACQ(2,1,2) at 348/19:23:02 acquired in fine lock backup on FGS 2 only, with QF1STOPF and QSTOP flags set on FGS 1 at 19:27:37. No other flags were seen. Previous acquisition at 17:50:11 was successful. 11101 – GSAcq(2,3,2) failed to RGA Hold(gyro Control) GSAcq(2,3,2) scheduled at 349/19:15:18 – 19:23:23 failed to RGA Hold due to (QF2STOPF) stop flag indication on FGS-2 during acquisition walkdown. Scheduled Astrometry FGS1 did not attempt. Pre-acquisition OBADs had (RSS) values of 931.61 and 4.46 arcseconds. OBAD/MAP scheduled at 349/19:23:23 had 3-axis (RSS) value of 4.18 arcseconds. 11102 – GSAcq(1,2,1) failed to RGA Hold At AOS (350/00:51:00) observed that GSAcq (1,2,1) scheduled from 00:41:58 – 00:49:52 had failed to RGA Hold due to QSTOP & QF2STOPF flags on FGS 2. No 486 ESB messages were received. Due to LOS, the data from OBAD 1 is unavailable till an engineering data dump is performed. OBAD 2 data showed the following results: V1 1.39, V2 4.19, V3 3.00, RSS 5.34. OBAD MAP at 01:38:52 showed the following results: V1 -2.38, V2 -11.86, V3 9.58, RSS 15.43 REAcq(1,2,1) @ 350/02:06:00 was successful 11103 – GSAcq(2,1,2) results in finelock backup (2,0,2) using FGS-2 Upon acquisition of signal at 350/20:35:20, the GSAcq(2,1,2) scheduled at 350/19:33:11 – 19:41:16 had resulted to finelock backup (2,0,2) using FGS-2,due to stop flag (QF1STOPF) indication on FGS-1. Pre-acquisition OBAD1 had attitude error correction (RSS) value of 1824.19 arcseconds. OBAD2 attitude error correction (RSS) not available pending future ETR Dump. Post-acq OBAD/MAP had (RSS) value of 19.65 arcseconds. Subsequent REacq(2,1,2) scheduled at 350/21:07:49 using same guide star pair resulted to finelock backup (2,0,2) using FGS-2 due to stop flag on FGS-1. 11104 – GSAcq(1,2,2) resulted in Fine Lock Back-up (1,0,1) GSAcq (1,2,2) scheduled from 09:36:13 – 09:43:26 resulted in Fine Lock Back-up (1,0,1) using FGS 1. This was due to QF2STOPF flag on FGS 2 and QSTOP flag. At 09:39:50 received 486 ESB message 1808 “TxG FHST Sanity Check Failed”. Pre-acquisition OBAD1 had attitude error correction (RSS) value of 2691.62 arcseconds. Pre-acquisition OBAD2 had attitude error correction (RSS) value of 5.39 arcseconds. Post acquisition OBAD MAP was not scheduled. COMPLETED OPS REQUEST: (None) COMPLETED OPS NOTES: (None) SIGNIFICANT EVENTS: FSW 3.1 Release B was successfully installed into HST486 EEPROM at 348/13:00:34. The load completed successfully and the valid block counter was verified. The post installation EEPROM dump was completed at 348/15:16:59, and the Compare Best Estimate of the dump file against the EEPROM load showed no miscompares and no missing blocks. FSW also verified the contents of the memory dump.
SCHEDULED SUCCESSFUL
FGS GSacq 27 25
FGS REacq 17 17
OBAD with Maneuver 88 88
