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Daily 3652
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3652 PERIOD COVERED: DOY 194 OBSERVATIONS SCHEDULED ACS/HRC 10272 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 environment 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 their 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. Use of ACS rather than WFPC2 will make our snapshot survey even more valuable than our Cycle 9 survey. This Proposal is complementary to our Cycle 13 archival proposal, in which we outline a plan for using existing HST images to glean information about SN environments. ACS/HRC/WFC 10044 ACS internal CTE monitor The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be closely monitored at regular intervals, because it is likely to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} and First Pixel Response {FPR} data will be obtained over a range of signal levels for both the Wide Field Channel {WFC}, and the High Resolution Channel {HRC}. ACS/HRC/WFC 10061 CCD Daily Monitor This program consists of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. This programme will be executed once a day for the entire lifetime of ACS. ACS/WFC 10181 ACS/NICMOS Imaging of Bright Lyman Break Galaxy Candidates from SDSS The recent surprising discovery of six unusually bright {r~20 mag} Lyman break galaxy {LBG} candidates with z=2.45-2.80 in the Sloan Digital Sky Survey {SDSS} raises a number of questions. Specifically, what is the true nature of these objects, and what role if any is played by gravitational lensing? We propose to use the superior resolution and sensitivity of ACS and NICMOS to obtain deep images of these objects and their environments. Compared to SDSS images, HST will allow us to determine their morphologies {extended, point-source, or lensed}, the appearance of their environments {rich or poor}, and to detect any faint foreground groups or clusters that might be responsible for lensing these objects. All outcomes would be intriguing. If the objects are lensed, it increases from 1 {MS1512-cB58} to 7 the number of normal LBGs bright enough to study individually. If they are instead unlensed point sources, they will represent a new class of previously unidentified absorption-line quasars. Finally, if they are unlensed and extended star-forming galaxies, they are at least 4mag brighter than L_* LBGs, thus making them the most luminous star-forming objects yet seen, representing a heretofore unknown extreme population of objects. HST 9382 A Large Targeted Survey for z 1.6 Damped Lyman Alpha Lines in SDSS QSO MgII-FeII Systems. We have searched the first public release of SDSS QSO spectra for low-z {z1.65} metal absorption lines and found over 200 large rest equivalent width MgII-FeII systems. Previously, we empirically showed that such systems are good tracers of large neutral gas columns, with ~50% being classical damped Lyman alpha {DLA} systems {N_HI=2*10^20 cm^-2}. Here we propose to follow up a well-defined subset of 79 of them to search for DLAs with 0.47z1.60. Only QSOs brighter than g'=19 were selected. The QSO emission and DLA absorption redshifts were constrained to virtually eliminate data loss due to intervening Lyman limit absorption. Consequently, we expect to discover ~40 new DLAs, which is a three-fold increase in this redshift interval. This will significantly improve our earlier low-z DLA statistical results on their incidence, cosmological mass density, and N_HI distribution. The results will also allow us to better quantify the empirical DLA -- metal-line correlation. With this improved understanding, the need for follow-up UV spectroscopy will lessen and, with the release of the final database of SDSS QSO spectra {an ~25-fold increase}, the number of low-z DLAs could be increased arbitrarily. Thus, the power of the large and statistically-sound SDSS database in combination with a proven technique for finding low-z DLAs will, over the next few years, essentially solve the problem of making an accurate determination of the cosmic evolution of the neutral gas component down to z~0.4. NIC1/NIC2/NIC3 8793 NICMOS Post-SAA calibration - CR Persistence Part 4 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. NIC1/NIC2/NIC3 9995 Photometric Stability This NICMOS calibration proposal carries out photometric monitoring observations during Cycle 12. The format of the program is identical to that of the Cycle 11 program 9639, except that the frequency has been reduced to bimonthly. STIS/CCD 10018 CCD Dark Monitor-Part 2 Monitor the darks for the STIS CCD. STIS/CCD 10020 CCD Bias Monitor - Part 2 Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns. STIS/CCD 10175 STIS Snapshot Survey of Boron Abundances in Early-B Stars Boron abundances in massive stars provide a unique constraint for new theoretical models of stellar evolution that include rotation. We propose to use STIS to measure the B III doublet near 2066 Angstroms in a large sample of early-B stars. A high priority will be placed on obtaining abundances for several stars in each of a number of different young clusters, associations, and star forming regions. This will allow quantitative comparison with theoretical predictions of rotationally driven mixing in early B stars as function of mass, age, and rotation rate. Since boron abundance measurements are not possible for large vsin{i} values, and sin{i} is not known for individual stars, a large sample is required to statistically test the predictions of boron depletion as a function of the true rotation rate. For bright nearby stars {25 targets} we will use the G230MB grating and obtain very high S/N {200:1}. This avoids the need for an ND filter which would discard 99% of the photons. Spectral synthesis techniques will allow us to derive accurate abundances despite the moderate resolution of this grating, even for stars with relatively high vsin{i} values. This is especially important in testing rotational models, as current abundance measurements are mostly for stars with much lower than average rotation rates. For fainter, more distant stars {27 targets} we will use the E230M or E230H grating with the 0.2x0.2 aperture. STIS/MA1 10034 Cycle 12 MAMA Dark Monitor This test performs the routine monitoring of the MAMA detector dark noise. This proposal will provide the primary means of checking on health of the MAMA detectors systems through frequent monitoring of the background count rate. The purpose is to look for evidence of change in dark indicative of detector problem developing. STIS/MA1/MA2 9739 Are We Missing the Dominant Sites of Star Formation in Local UV-Bright Starbursts? We propose to explore the ages, extinctions, and masses of young stellar clusters in four nearby dwarf starburst galaxies {He 2-10, NGC 5253, NGC 4214, and IIZw40}. We will combine available archival data with new, high resolution HST observations from the ultraviolet to the infrared. All four galaxies are known from ground based radio/infrared observations to contain highly obscured, massive stellar clusters, which dominate the far infrared flux. Despite the fact that almost all of the infrared flux comes from regions which are obscured at UV and optical wavelengths, these galaxies are consistent with the well known correlation between the UV slope {beta} and the ratio of far infrared flux to ultraviolet flux at 1600 Angstroms. Because the UV and IR fluxes are decoupled, this observation implies that a simple foreground screen model, where UV photons from hot stars are reprocessed into the infrared by local dust, is not the proper interpretation for why these galaxies follow the beta relation. We propose to investigate the underlying mechanisms responsible for this observed correlation in these UV bright galaxies, and explore the implication for high redshift starbursts. WFPC2 10067 WFPC2 Cycle 12 Decontaminations and Associated Observations This proposal is for the monthly 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 10071 WFPC2 CYCLE 12 Supplemental Darks Part 3/3 This dark calibration program obtains 3 dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels. WFPC2 9816 Proper motion kinematics in Galactic bulge/bar fields With this proposal we continue a successful programme to measure proper motions in fields in the galactic bulge. We are able to reach accuracies of ca 10km/s in transverse motion at a distance of 8kpc, for thousands of stars per WFPC2 field. In combination with VLT spectroscopic radial velocities and metallicity indices, we will be able to construct a full dynamical and stellar-population model for our Bulge. Previous fields in this programme were on the minor axis; the fields proposed here {using first epoch observations from 1995-1998 from the archive} lie in the first quadrant, on the near side of the Galactic bar. We also wish to establish first-epoch observations in the 4th quadrant, where no suitable data exist so far. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: None OPS NOTES EXECUTED: None SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 11 11 FGS REacq 6 6 FHST Update 13 13 LOSS of LOCK SIGNIFICANT EVENTS: None |
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