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Daily 3624
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3624 PERIOD COVERED: DOY 153 OBSERVATIONS SCHEDULED ACS/HRC/WFC 10048 Stability of the ACS CCD: Flat fielding, Photometry, Geometry This program will verify that the low frequency flat fielding, the photometry, and the geometric distortion are stable in time and across the field of view of the CCD detectors. A moderately crowded stellar field, located ~6' West of the center of the cluster 47 Tuc, is observed every three months with the WFC and HRC using the full suite of broad and narrow band filters. The same field has been observed during SMOV to derive low frequency corrections to the ground flats and to create a master catalogue of positions and magnitudes from dithered observations of the cluster. In Cycle 11, this field was observed again using single pointings at various roll angles. The positions and magnitudes of objects are used to monitor local and large scale variations in the plate scale and the sensitivity of the detectors. The Cycle 12 program will continue to monitor these effects and will derive an independent measure of the detector CTE. ACS/HRC/WFC 10060 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/HRC/WFC 9728 Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae Type Ia supernovae {SNe Ia} provide the only direct evidence for an accelerating universe, an extraordinary result that needs the most rigorous test. The case for cosmic acceleration rests on the observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than they would be in a universe without acceleration. A powerful and straightforward way to assess the reliability of the SN Ia measurement and the conceptual framework of its interpretation is to look for cosmic deceleration at z 1. This would be a clear signature of a mixed dark-matter and dark-energy universe. Systematic errors in the SNe Ia result attributed to grey dust or cosmic evolution of the SN Ia peak luminosity would not show this change of sign. We have obtained a toehold on this putative ``epoch of deceleration'' with SN 1997ff at z = 1.7, and 3 more at z 1 from our Cycle 11 program, all found and followed by HST. However, this is too important a test to rest on just a few objects, anyone of which could be subject to a lensed line-of-sight or misidentification. Here we propose to extend our measurement with observations of twelve SNe Ia in the range 1.0 z 1.5 or 6 such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be discovered as a byproduct from proposed Treasury and DD programs. These objects will provide a much firmer foundation for a conclusion that touches on important questions of fundamental physics. ACS/HRC/WFC 9781 Galaxy Evolution in Action : The Detailed Morphology of Post-Starburst Galaxy If galaxies evolve morphologically, then some should be in transition between late and early types. One proposed evolutionary mechanism is a galaxy-galaxy merger, but evolved merger products are difficult to find. Fortunately, spectroscopic surveys have now uncovered large numbers of E+A galaxies, a class of objects whose post-starburst spectra, current lack of HI gas, and pressure-supported kinematics suggest that they are the missing panel that connects the "Toomre sequence" of merging spirals with normal ellipticals and S0s. Our first HST observations of five of these galaxies are intriguing. We find a considerable range of tidally disturbed morphologies, an "E+A" fundamental plane, significant differences among the color gradients within 1 kpc {~0.8''}, and populations of bright, blue globular clusters. These initial results are difficult to interpret, however, because they are drawn from a small sample of galaxies whose very blue overall colors may have selected a particular evolutionary path of E+As. Here we propose for ACS imaging of the remaining 15 E+As from the Las Campanas Redshift Survey to probe the full range of E+A properties. The proposed observations will allow us to 1} determine what fraction of the interactions that lead to E+As destroy all disk-like structures {and therefore necessarily lead to elliptical formation}, 2} measure the inner color gradients and constrain the spatial distribution of stars produced as gas sinks to the center during a merger, and 3} determine whether these interactions produce globular clusters in the required numbers to account for the increased specific frequency of clusters in early-type galaxies. ACS/WFC 10055 ACS Polarization Calibration This proposal aims to address several specific issues for the polarization calibration: {1} variations in calibration with position on the detector {field dependence}, {2} dependence on telescope roll-angle relative to the target, {3} orientation of the polarizer axes, and {4} geometric distortion contributed by the polarizers. ACS/WFC/WFPC2 9774 Young Massive Clusters in Spiral Galaxies and the Connection with Open Clusters We propose to carry out a census of star clusters in the disks of the nearby spiral galaxies NGC 45, NGC 1313, NGC 4395, NGC 5236 and NGC 7793. Using ACS, we will identify much fainter and older star clusters than possible in previous ground-based surveys, or even in HST imaging of more distant galaxies. For the first time, we will directly explore the connection between young "massive'' {or "super''} star clusters {YMCs} and lower-mass "open'' clusters in different star forming environments. We will test the universality of the luminosity- and mass functions of stellar clusters and establish whether the presence of YMCs is a result of a top-heavy cluster luminosity function, or follows from generally richer cluster systems. Our target galaxies span a range of morphological properties, surface brightness and star formation rate. Some of them are known from ground-based studies to host large numbers of YMCs while others have more modest cluster populations. However, previous ground-based data were restricted to luminous clusters younger than about 500 Myr. Here we will extend the search to clusters formed throughout the entire lifetime of each galaxy and reach clusters with properties typical of the Milky Way open clusters. This will allow us to close the gap between studies of extragalactic and Galactic disk clusters. FGS 9879 An Astrometric Calibration of the Cepheid Period-Luminosity Relation We propose to measure the parallaxes of 10 Galactic Cepheid variables. When these parallaxes {with 1-sigma precisions of 10% or better} are added to our recent HST FGS parallax determination of delta Cep {Benedict et al 2002}, we anticipate determining the Period-Luminosity relation zero point with a 0.03 mag precision. In addition to permitting the test of assumptions that enter into other Cepheid distance determination techniques, this calibration will reintroduce Galactic Cepheids as a fundamental step in the extragalactic distance scale ladder. A Period-Luminosity relation derived from solar metallicity Cepheids can be applied directly to extragalactic solar metallicity Cepheids, removing the need to bridge with the Large Magellanic Cloud and its associated metallicity complications. FGS 9972 Calibrating the Mass-Luminosity Relation at the End of the Main Sequence We propose to use HST-FGS1R to calibrate the mass-luminosity relation {MLR} for stars less massive than 0.2 Msun, with special emphasis on objects near the stellar/brown dwarf border. Our goals are to determine M_V values to 0.05 magnitude, masses to 5 than double the number of objects with masses determined to be less than 0.20 Msun. This program uses the combination of HST-FGS3/FGS1R at optical wavelengths and ground-based infrared interferometry to examine nearby, subarcsecond binary systems. As a result of these measurements, we are deriving high quality luminosities and masses for the components in the observed systems, and characterizing their spectral energy distributions from 0.5 to 2.2 Mum. Several of the objects included have M 0.1 Msun, placing them at the very end of the stellar main sequence. Three of the targets are brown dwarf candidates, including the current low mass record holder, GJ 1245C, with a mass of 0.062 +/- 0.004 Msun. The payoff of this proposal is high because all 10 of the systems selected have already been resolved with HST- FGS3/FGS1R during Cycles 5--10 and contain most of the reddest objects for which masses can be determined. NIC/NIC3 9865 The NICMOS Parallel Observing Program We propose to continue managing the NICMOS pure parallel program. Based on our experience, we are well prepared to make optimal use of the parallel opportunities. The improved sensitivity and efficiency of our observations will substantially increase the number of line-emitting galaxies detected. As our previous work has demonstrated, the most frequently detected line is Halpha at 0.7z1.9, which provides an excellent measure of current star formation rate. We will also detect star-forming and active galaxies in other redshift ranges using other emission lines. The grism observations will produce by far the best available Halpha luminosity functions over the crucial--but poorly observed--redshift range where galaxies appear to have assembled most of their stellar mass. This key process of galaxy evolution needs to be studied with IR data; we found that observations at shorter wavelengths appear to have missed a large fraction of the star-formation in galaxies, due to dust reddening. We will also obtain deep F110W and F160W images, to examine the space densities and morphologies of faint red galaxies. In addition to carrying out the public parallels, we will make the fully reduced and calibrated images and spectra available on-line, with some ground-based data for the deepest parallel fields included. NIC1/NIC2/NIC3 8792 NICMOS Post-SAA calibration - CR Persistence Part 3 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. 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/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. WFPC2 10070 WFPC2 CYCLE 12 Supplemental Darks Part 2/3 This dark calibration program obtains 3 dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: 17175-0 Load Battery Reconditioning Macro version D @ 153/10:17z OPS NOTES EXECUTED: NONE SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 09 09 FGS REacq 06 06 FHST Update 14 14 LOSS of LOCK SIGNIFICANT EVENTS: Successfully started commanding for Battery 4 Capacity Test on schedule @ 153/10:10Z with set-up portion of script (OR 17172 with attached script). Solar Array Section 4 was connected to Diode Bus C during orbit night @ 153/11:14Z, Battery 4 discharge through the high-rate resistor was commanded @ 153/11:15Z. When Battery 4 Voltage discharge reached 26.23 Volts, the discharge was switched to the low-rate resistor by the ACR @ 153/20:11Z. |
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