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Daily 3729
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3729 PERIOD COVERED: DOY 307 OBSERVATIONS SCHEDULED ACS/HRC 10137 Cluster Archeology: The Origin of Ultra-compact Dwarf Galaxies Ultra-compact dwarf {UCD} galaxies are a new type of galaxy we have discovered in the central regions of the Fornax and Virgo galaxy clusters. Our most recent observations in the Fornax Cluster show that UCDs outnumber normal galaxies in the centre of that cluster. Here we propose snapshot imaging of UCDs in the Fornax and Virgo clusters to test theories of how these fascinating objects formed. In particular we wish to image Virgo cluster UCDs for which we have ground-based Keck spectroscopy to test predictions that they formed more recently than the Fornax UCDs. ACS/HRC 10199 The Most Massive Galaxies in the Universe: Double Trouble? We are proposing an HST snapshot survey of 70 objects with velocity dispersion larger than 350 km/s, selected from the Sloan Digital Sky Survey. Potentially this sample contains the most massive galaxies in the Universe. Some of these objects may be superpositions; HST imaging is the key to determining if they are single and massive or if they are two objects in projection. The objects which HST imaging shows to be single objects are interesting because they potentially harbor the most massive black holes, and because their existence places strong constraints on galaxy formation models. When combined with ground based data already in hand, the objects which HST imaging shows are superpositions provide valuable information about interaction rates of early-type galaxies as well as their dust content. They also constrain the allowed parameter space for models of binary gravitational lenses {such models are currently invoked to explain discrepancies in the distribution of lensed image flux ratios and separations}. ACS/HRC 10377 ACS Earth Flats High signal sky flats will be obtained by observing the bright Earth with the HRC and WFC. These observations will be used to verify the accuracy of the flats currently used by the pipeline and will provide a comparison with flats derived via other techniques: L-flats from stellar observations, sky flats from stacked GO observations, and internal flats using the calibration lamps. Weekly coronagraphic monitoring is required to assess the changing position of the spots. ACS/WFC 10006 Black Hole X-ray Novae in M31 During A01-3 we found 22 Black Hole X-ray Novae {BHXN} in M31 using Chandra, and with HST {WFPC2} found two optical counterparts. Our results suggest either a surprisingly high ratio of BH to NS binaries, or a surprisingly high duty cycle for BHXN. We propose to continue this program, with the goals of understanding the relative number of BH vs. NS X-ray binaries in the M31 bulge, and determining the orbital period distribution and duty cycles of these BHXN. Continued observations can determine the duty cycle. The new ACS will allow us to go 2 mags deeper than the WFPC2, and could triple the number of optical counterparts and therefore orbital period estimates. M31 is the only galaxy near enough to allow this extragalactic survey for BHXN. ACS/WFC 10118 Imaging the Chemical Distribution in Type Ia SN Ejecta We know Type Ia supernovae are thermonuclear explosions of CO white dwarfs, but we don't know the specifics of how the nuclear burning process proceeds from the core outward once it starts. The thermonuclear instability is thought to start off as a subsonic, turbulent deflagration or burning wave but then, at some point, may transition into a blast or detonation wave. In such "delayed detonation" models, differences between normal and subluminous Type Ia SNe reflect differences in the amount of burning that has occurred in the pre-detonation phase. More burning helps to pre-expand the WD before passage of the detontation wave, which then results in different final element abundances and internal Fe-rich ejecta structure. Directly imaging the 2-D chemical distribution of ejecta from a Type Ia SN is actually possible in the case of the subluminous Type Ia SN 1885, which occurred on the near-side of M31's central bulge. This 119 year old remnant is visible -- from its core to its outer edge -- via strong optical/UV Ca and Fe line absorptions. Remarkably, the SNR appears to still be in a nearly free expansion phase, meaning that the elemental stratification seen present today accurately reflects SN Ia explosive nucleosynthesis physics. We propose to obtain ACS WFC/HRC images of SN 1885 in order to take advantage of this extraordinary situation: Having a young, nearby Type Ia SN remnant visible in silhouette against a galaxy-size light table. These unique observations will reveal a SN Ia's Ca and Fe ejecta distribution, density structure, sphericity, and ionization state as a function of expansion velocity, thereby confronting various SN Ia models with detailed ejecta stratification and expansion velocity maps. 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 10361 Earth Flats This proposal monitors flatfield stability. This proposal obtains sequences of Earth streak flats to construct high quality flat fields for the WFPC2 filter set. These flat fields will allow mapping of the OTA illumination pattern and will be used in conjunction with previous internal and external flats to generate new pipeline superflats. These Earth flats will complement the Earth flat data obtained during cycles 4-12. 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. 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. NIC2 10176 Coronagraphic Survey for Giant Planets Around Nearby Young Stars A systematic imaging search for extra-solar Jovian planets is now possible thanks to recent progress in identifying "young stars near Earth". For most of the proposed young {~ 30 Myrs} and nearby {~ 60 pc} targets, we can detect a few Jupiter-mass planets as close as a few tens of AUs from the primary stars. This represents the first time that potential analogs of our solar system - that is planetary systems with giant planets having semi-major axes comparable to those of the four giant planets of the Solar System - come within the grasp of existing instrumentation. Our proposed targets have not been observed for planets with the Hubble Space Telescope previously. Considering the very successful earlier NICMOS observations of low mass brown dwarfs and planetary disks among members of the TW Hydrae Association, a fair fraction of our targets should also turn out to posses low mass brown dwarfs, giant planets, or dusty planetary disks because our targets are similar to {or even better than} the TW Hydrae stars in terms of youth and proximity to Earth. Should HST time be awarded and planetary mass candidates be found, proper motion follow-up of candidate planets will be done with ground-based AOs. WFPC2 10360 WFPC2 CYCLE 13 INTERNAL MONITOR This calibration proposal is the Cycle 13 routine internal monitor for WFPC2, to be run weekly to monitor the health of the cameras. A variety of internal exposures are obtained in order to provide a monitor of the integrity of the CCD camera electronics in both bays {gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a monitor for possible buildup of contaminants on the CCD windows. WFPC2 10363 WFPC2 CYCLE 13 Intflat and Visflat Sweeps and Filter Rotation Anomaly Monitor Using intflat observations, this WFPC2 proposal is designed to monitor the pixel-to-pixel flatfield response and provide a linearity check. The intflat sequences, to be done once during the year, are similar to those from the Cycle 12 program 10075. The images will provide a backup database in the event of complete failure of the visflat lamp as well as allow monitoring of the gain ratios. The sweep is a complete set of internal flats, cycling through both shutter blades and both gains. The linearity test consists of a series of intflats in F555W, in each gain and each shutter. As in Cycle 12, we plan to continue to take extra visflat, intflat, and earthflat exposures to test the repeatability of filter wheel motions. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9579 GSAcq (1,2,2) Loss of Lock. OTA SE review of PTAS processing revealed GSAcq(1,2,2) required two attempts to successfully achieve fine lock. Fine Lock was originally achieved on FGS1 at 299/03:43:05 and on FGS2 at 03:43:49. Both FGSs returned to SSM control at 03:45:20 and the acquisition was ultimately successful at 03:46:18. COMPLETED OPS REQs: 17299-0 - Null genslew for proposal 10398 (slot 13) @ 307/1811z OPS NOTES EXECUTED: None SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 8 8 FGS Reacq 9 9 FHST Update 10 10 LOSS of LOCK SIGNIFICANT EVENTS: None |
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