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Daily 3763
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3763 PERIOD COVERED: DOYs 358-361 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. FGS 10386 Long Term Monitoring of FGS1r in Position Mode It is known from our experience with FGS3, and later with FGS1r, that an FGS on orbit experiences long term evolution, presumably due to disorption of water from the instrument's graphite epoxy composits. This manifests principly as a change in the plate scale and secondarily as a change in the geometric distortions. These effects are well modeled by adjustments to the rhoA and kA parameters which are used to transform the star selector servo angles into FGS {x, y} detector space coordinates. By observing the relative positions of selected stars in a standard cluster at a fixed telescope pointing and orientation, the evolution of rhoA and kA can be monitored and calibrated to preserve the astrometric performance of FGS1r. NIC1/NIC2/NIC3 10381 Photometric Stability This NICMOS calibration proposal carries out photometric monitoring observations during Cycle 13. The format of the program is identical to that of the Cycle 12 program 9995 NIC1/NIC2/NIC3 10380 Cycle 13 NICMOS dark current, shading profile, and read noise monitoring program The purpose of this proposal is to monitor the dark current, read noise, and shading profile for all three NICMOS detectors throughout the duration of Cycle 13. This proposal is an essentially unchanged continuation of PID 9993 which cover the duration of Cycle 12. ACS/HRC/WFC 10367 ACS CCDs daily monitor- cycle 13 - part 1 This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. ACS/WFC 10326 The Morphological, Photometric, and Spectroscopic Properties of Intermediate Redshift Cluster Galaxies We will use the ACS/WFC to image 8 fields in the outskirts of the kT=5.8keV, X-ray cluster RX J0152-13 at z=0.83, for which we obtained imaging in four central fields during Cycle 11. The resulting wide-field mosaic of RX J0152-13 will enable direct study of the population of galaxies falling into this cluster and will provide a much needed comparison to our on-going wide-field study of the more massive, 10.5keV cluster MS1054-03 at the same redshift. Imaging RX J0152-13 to twice its viral radius enables us to: {1} trace the transformation of infalling field spirals into cluster early-types using, e.g., the morphology-density relation to large radii and very low local densities; {2} determine the importance of galaxy-galaxy interactions, i.e., whether the frequency of such encounters in the infall region is as unexpectedly high as found in MS1054-03; and {3} study in detail the star-formation histories of the most recently accreted members via accurate colors and morphologies. A comparison of RX J0152-13 with MS1054-03 will also allow us to directly probe the dependence of galaxy evolution on cluster mass. Only by pairing the wide-field ACS mosaic of RX J0152-13 with multi-object spectroscopy from the Magellan, Keck, and VLT telescopes can we test predictions from galaxy formation models, understand how field spirals evolve into early-type cluster members, and better constrain the formation of galaxies in general. ACS/HRC/WFC 10267 The Shadow Echoes of the Unique R Coronae Borealis Star, UW Cen Understanding the R Coronae Borealis {RCB} stars is a key test for any theory aiming to explain hydrogen deficiency in post-AGB stars. The RCB stars are rare hydrogen- deficient carbon-rich supergiants that undergo very spectacular declines in brightness of up to 8 magnitudes at irregular intervals as dust forms near the star along the line of sight. UW Cen is unique among the cool RCB stars in having a visible circumstellar shell. The morphology of the nebula appears to change as different parts are illuminated by light from the central star modulated by shifting, thick dust clouds near its surface. The central star acts like a "lighthouse, " shining through gaps between the near-star dust clouds, and lighting up different portions of the outer nebula. We propose a scientific program in which a small number of observations using ACS/HRC will exploit UW Cen's unique circumstellar shell to address two critical elements in understanding RCB stars: determining an accurate distance to the star, and studying the otherwise unobservable dust clouds forming near the star's surface. We will model the images using Monte Carlo techniques to calculate the radiative transfer through arbitrary distributions of dust viewed from any angle. ACS/WFC/WFPC2 10265 The Formation History of Andromeda We propose deep observations of Andromeda's outer disk and giant tidal stream, to reconstruct their star formation histories. As the nearest giant galaxy, Andromeda offers the best testing ground for understanding galaxy formation and evolution. Given the dramatic increase in sensitivity offered by the ACS, we can now resolve stars on the old main sequence in the other giant spiral of the Local Group, and employ the same direct age diagnostics that have been used for decades in the study of Galactic globular clusters. In Cycle 11, we successfully observed a field in the Andromeda halo and constructed a deep color-magnitude diagram reaching well below the oldest main sequence turnoff. In Cycle 13, we propose to extend these observations to the outer disk and tidal stream of Andromeda, to constrain their star formation histories and compare them to that of the halo. The combined observations from these two programs will offer a dramatic advance in our understanding of the overall evolution of spiral galaxies. ACS/WFC 10210 Groups of Dwarf Galaxies: Pools of Mostly Dark Matter? Within 5 Mpc, there are 6 groups with well-known luminous galaxies but there also appears to be a comparable number of groups containing only dwarfs. If these dwarf entities are truly bound then M/L values are an order of magnitude higher than values found for groups with luminous spiral galaxies. There are theoretical reasons to anticipate that low mass halos may frequently be mostly dark. The dynamical influence of low mass halos is negligible in familiar groups with luminous members. By contrast, a study of the dynamics of `groups of dwarfs' may provide direct evidence of the existence of dark matter potential wells with few baryons. The goal of the present study is to gather detailed information on the 3-D distribution of dwarf galaxies suspected to lie within 7 groups of dwarfs within 5 Mpc. Distances with 7% relative accuracy can be measured with the Tip of the Giant Branch method with ACS and integrations within 1 orbit per target. ACS/WFC/NIC3 10195 Probing the Surroundings of a Highly Luminous Redshift 6.5 Galaxy We propose deep images of a recently discovered galaxy at z=6.535, which is among the most luminous Lyman-alpha emitting galaxies known at high redshift. The brightness and rarity of this source imply that it is associated with a high peak in the matter density distribution. {It is the brightest Lyman alpha source in 2e5 comoving Mpc3, with a luminosity of 6 L*.} Further objects in this peak are expected to be visible with HST's sensitivity. The Lyman alpha line has a large rest frame equivalent width, with a lower bound 100 Angstroms. Such a large equivalent width would be impossible for objects embedded in neutral gas, and instead requires either that {a} the universe was reionized before z=6.5 or {b} the galaxy resides in a local ionized bubble, in which case an additional contribution to the ionizing photon budget from presently undetected neighbors is required. With 19 orbits of ACS and NICMOS imaging, we will measure this object's morphology and spectral energy distribution, thus searching for either active nuclei or old stellar populations. We will also search for possible neighbors, which could establish the first known galaxy group at z6, and may provide sufficient ionizing flux to allow the escape of the observed Lyman alpha photons in a neutral universe. If neighbors are not found, it will lead to an upper bound on the neutral fraction in the general IGM at z=6.5. ACS/WFC 10174 Dark-matter halos and evolution of high-z early-type galaxies Gravitational lensing and stellar dynamics provide two complementary methods to determine the mass distribution and evolution of luminous and dark-matter in early-type {E/S0} galaxies. The combined study of stellar dynamics and gravitational lensing allows one to break degeneracies inherent to each method separately, providing a clean probe of the internal structure of massive galaxies. Since most lens galaxies are at redshifts z=0.1-1.0, they also provide the required look-back time to study their structural and stellar-population evolution. We recently analyzed 5 E/S0 lens galaxies between z=0.5 and 1.0, combining exquisite Hubble Space Telescope imaging data with kinematic data from ground-based Keck spectroscopy, placing the first precise constraints on the dark- matter mass fraction and its inner slope beyond the local Universe. To expand the sample to ~30 systems -- required to study potential trends and evolution in the E/S0 mass profiles -- we propose to target the 49 E/S0 lens-galaxy candidates discovered by Bolton et al. {2004} from the Sloan Digital Sky Survey {SDSS}. With the average lens rate being 40% and some systems having a lensing probability close to unity, we expect to discover ~20 strong gravitational lenses from the sample. This will triple the current sample of 9 E/S0 systems, with data in hand. With the sample of 30 systems, we will be able to determine the average slope of the dark-matter and total mass profile of E/S0 galaxies to 10% and 4% accuracy, respectively. If present, we can simultaneously detect 10% evolution in the total mass slope with 95% confidence. This will provide unprecedented constraints on E/S0 galaxies beyond the local Universe and allow a stringent test of their formation scenarios and the standard cosmological model. NIC2 10173 Infrared Snapshots of 3CR Radio Galaxies Radio galaxies are an important class of extragalactic objects: they are one of the most energetic astrophysical phenomena and they provide an exceptional probe of the evolving Universe, lying typically in high density regions but well-represented across a wide redshift range. In earlier Cycles we carried out extensive HST observations of the 3CR sources in order to acquire a complete and quantitative inventory of the structure, contents and evolution of these important objects. Amongst the results, we discovered new optical jets, dust lanes, face-on disks with optical jets, and revealed point-like nuclei whose properties support FR-I/BL Lac unified schemes. Here, we propose to obtain NICMOS infrared images of 3CR sources with z0.3 as a major enhancement to an already superb dataset. We aim to deshroud dusty galaxies, study the underlying host galaxy free from the distorting effects of dust, locate hidden regions of star formation and establish the physical characteristics of the dust itself. We will measure frequency and spectral energy distributions of point-like nuclei, expected to be stronger and more prevalent in the IR, seek spectral turnovers in known synchrotron jets and find new jets. We will strongly test unified AGN schemes and merge these data with existing X-ray to radio observations. The resulting database will be an incredibly valuable resource to the astronomical community for years to come. ACS/WFC 10135 Unveiling the Progenitors and Physics of Cosmic Explosions GRBs and XRFs are clearly highly asymmetric explosions and require a long-lived power source {central engine}. In contrast, nearby core-collapse events are essentially spherical explosions. However, the failure of spherical neutrino driven collapses has led to the idea that asymmetric energy release is essential for the explosion. The recent finding of a Type Ic SN in GRB 030329, the association of the low energy event GRB 980425 with SN 1998bw, the theoretical development discussed above and the rise of collapsar models make it timely to consider whether all these explosions contain engines. Given the uncertainties in theoretical modeling it is clear that observations are needed to guide models. A priori there is little reason to expect connection between the ultra- relativistic jet that powers the GRB and the explosive nucleosynthesis of the ~0.5 solar masses of Nickel-56 that powers the accompanying supernova. We propose a comprehensive program of ACS photometric searches {and measurements} for SNe associated with GRBs and XRFs. In concert, we will undertake ground-based spectroscopy to determine velocity widths, and measure engine parameters from pan- chromatic afterglow observations. Our goal is to produce a comprehensive database of engine and SN physical parameters against which theoretical modeling will be guided. ACS/WFC/NIC3/WFPC2 10134 The Evolution and Assembly of Galactic Disks:Integrated studies of mass, stars and gas in the Extended Groth Strip This project is a 126-orbit imaging survey in F606W/F814W ACS to measure the evolution of galaxy disks from redshift z = 1.4 to the present. By combining HST imaging with existing observations in the Extended Groth Strip, we can for the first time simultaneously determine the mass in dark matter that underlies disks, the mass in stars within those disks, and the rate of formation of new stars from gas in the disks, for samples of 1, 000 objects. ACS observations are critical for this work, both for reliable identifications of disks and for determining their sizes and inclinations. Combining these data with the kinematics measured from high-resolution Keck DEIMOS spectra will give dynamical masses that include dark matter. Stellar masses can be measured separately using ground-based BRIK and Spitzer IRAC GTO data, while cross-calibrated star formation rates will come from DEEP2 spectra, GALEX, and Spitzer/MIPS. The field chosen is the only one where all multiwavelength data needed will be available in the near term. These data will show how the fundamental properties of disks {luminosity, rotation speed, scale length} and their scaling relations have evolved since z~1, and also will measure the build-up of stellar disks directly, providing fundamental tests of disk formation and evolution. In addition to the above study of disk galaxies, the data will also be used to measure the evolution of red-sequence galaxies and their associated stellar populations. ACS images will yield the number of red-sequence galaxies versus time, together with their total associated stellar mass. ACS images are crucial to classify red-sequence galaxies into normal E/S0s versus peculiar types and to measure radii, which will complete the suite of fundamental structural parameters needed to study evolution. We will measure the zeropoints of major scaling laws {Fundamental Plane, radius versus sigma}, as well as evolution in characteristic quantities such as L*, v*, and r*. Stellar population ages will be estimated from high-resolution Keck DEIMOS spectra and compared to SED evolution measured from GALEX, HST, Spitzer, and ground-based colors. Important for both disk and red-galaxy programs are parallel exposures to be taken with both NIC3 {J and H} and WFPC2 {B}. These are arranged so that ACS, WFPC2, and NIC3 all overlap where possible , providing a rich data set of galaxies imaged with all three HST cameras from B to H. These data will be used to measure restframe visible morphologies and UV star-formation rates for galaxies near the edge of the survey, to discover and count EROs below the Keck spectroscopic limit of R = 24, and to provide an improved database of photometric redshifts for galaxies in the overlap regions. ACS/HRC 10133 HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet As the nearest galaxy with an optical jet, M87 affords an unparalleled opportunity to study extragalactic jet phenomena at the highest resolution. During 2002, HST and Chandra monitoring of the M87 jet detected a dramatic flare in knot HST-1 located ~1" from the nucleus. As of late 2003 its brightness has increased twenty-fold in the optical band, and continues to increase sharply; the X-rays show a similarly dramatic outburst. In both bands HST-1 now greatly exceeds the nucleus in brightness. To our knowledge this is the first incidence of an optical or X-ray outburst from a jet region which is spatially distinct from the core source; this presents an unprecedented opportunity to study the processes responsible for non-thermal variability and the X-ray emission. We also include a brief HRC/ACS observations that will be used to gather spectral information and map the magnetic field structure. This monitoring is continued into Cycles 14 and 15. The results of this investigation are of key importance not only for understanding the nature of the X-ray emission of the M87 jet, but also for understanding flares in blazar jets, which are highly variable, but where we have never before been able to resolve the flaring region in the optical or X-rays. These observations will allow us to test synchrotron emission models for the X-ray outburst, constrain particle acceleration and loss timescales, and study the jet dynamics associated with this flaring component. Revisions 6 Oct 2004: We are replacing STIS visits 1-7 with ACS/HRC observations in new visits 31- 37. WFPC2 10132 UV Confirmation of New Quasar Sightlines Suitable for the Study of Intergalactic Helium The reionization of intergalactic helium is thought to have occurred between redshifts of about 3 and 4. The study of HeII Lyman-alpha absorption towards a half-dozen quasars at 2.7z3.5 demonstrates the great potential of such probes of the IGM, but the current critically-small sample limits confidence in resulting cosmological inferences. The requisite unobscured quasar sightlines to high-redshift are extremely rare, especially due to severe absorption in random intervening Lyman-limit systems, but SDSS provides hundreds of bright, new quasars at such redshifts potentially suitable for HeII studies. Our cycle 13 SNAP program proposes to verify the UV detectability of 40 new, bright, z2.9 SDSS quasars, but with special emphasis on extending helium studies to the highest redshift sightlines. Our proposed approach has already proven successful, and additional sightlines will enable follow-up spectal observations to measure the spectrum and evolution of the ionizing background radiation, the density of intergalactic baryons, and the epoch of reionization of the IGM. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: 17353-0 - Null Genslew for Proposal 10267 - Slot 14 @ 358/1636z OPS NOTES EXECUTED: None SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 32 32 FGS Reacq 46 46 FHST Update 39 39 LOSS of LOCK SIGNIFICANT EVENTS: None |
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