HST Daily Report # 3299

HUBBLE SPACE TELESCOPE DAILY REPORT # 3299 PERIOD COVERED: DOY 42 OBSERVATIONS SCHEDULED NICMOS 8790 NICMOS Post-SAA calibration - CR Persistence Part 1. 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. STIS/CCD 9066 Closing in on the Hydrogen Reionization Edge of the Universe. The Space Telescope Imaging Spectrograph (CCD) was used in parallel constrain the Hydrogen reionization edge in emission that marks the transition from a neutral to a fully ionized IGM at a predicted redshifts. FGS 9229 Orbits of Pre-Main Sequence Binaries We propose to image one ACS field containing four spectroscopically confirmed Ly-alpha emitters at because there are still no such objects with an accurately measured mass. In cycle 5 we began to map the orbits of young multiple star systems in Taurus using FGS3. In cycle 8 we switched to the more capable FGS1r. We propose to continue to observe these binary and triple systems so that we can establish their visual orbits. In addition to our Transfer mode observations, we include Position mode observations of reference field stars so that the position of the multiple systems' barycenter can be located, giving the relative masses of the components. In addition, the Position mode data will allow us to determine accurate parallaxes for these systems, and hence the physical, absolute masses of the young pre-main sequence stars along with absolute magnitudes. WFPC2/FGS 9332 WFPC2 Observations of Astrophysically Important Visual Binaries This is a continuation of a Cycle 7-8-9 Long-Term project. The program consists of annual or biannual WFPC2 or FGS observations of three visual binary stars that will ultimately yield fundamental astrophysical results, once their orbits and masses are determined. Our targets are the following: {1} Procyon {P=41 yr}, for which our first WFPC2 images yielded an extremely accurate angular separation of the bright F star and its very faint white-dwarf companion. Combined with ground-based astrometry of the bright star, our observation significantly revised downward the derived masses, and brought Procyon A into excellent agreement with theoretical evolutionary tracks for the first time. The mass of Procyon B, however, implies a completely unexpected chemical composition for the white dwarf, and now poses a sharp evolutionary puzzle. With the continued monitoring proposed here, we will obtain masses to an accuracy of better than 1%, providing a testbed for theories of Sun-like stars and white dwarfs. {2} G 107-70, a close double white dwarf {P=19 yr} that promises to add two accurate masses to the tiny handful of white-dwarf masses that are directly known from dynamical measurements. {3} Mu Cas {P=21 yr}, a famous metal-deficient G dwarf for which accurate masses will lead to the stars' helium contents, with cosmological implications. FGS 9347 FGS Astrometry of the Extrasolar Planet of Epsilon Eridani We propose observations with HST/FGS in Position Mode to determine the astrometric elements {perturbation orbit semimajor axis and inclination} of the candidate extra-solar planet around the K2 V star Epsilon Eridani that has been detected by Doppler spectroscopy. These observations will also permit us to determine the actual mass of the planet by providing the sin{i} factor which can not be determined with the radial velocity method. High precision radial velocity {RV} measurements spanning the years 1980.8--2000.0 for the nearby {3.22 pc} star Epsilon Eri show convincing variations with a period of ~ 7 yrs. These data represent a combination of six independent data sets taken with four different telescopes. A least squares orbital solution using robust estimation yields orbital parameters of period, P = 6.9 yrs, velocity K- amplitude = 19 m/s, eccentricity e = 0.6, projected companion mass M_B sin{i} = 0.83 M_Jupiter. An estimate of the inclination yields a perturbation semi-major axis, Alpha = 0arcs0022, easily within the reach of HST/FGS astrometry. ACS 9352 The Deceleration Test from Treasury Type Ia Supernovae at Redshifts 1.2 to 1.6 Type Ia supernovae {SNe Ia} provide the only direct evidence for an accelerating universe, an extraordinary result that needs a rigorous test. The case for cosmic acceleration rests on the observation that SNe Ia at z ~ 0.5 are ~ 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 SN Ia result attributed to grey dust or cosmic evolution of the SN Ia peak luminosity would not show this change of sign. We have demonstrated proof of this concept with a single SN Ia, SN 1997ff at z = 1.7, found and followed by HST. The results suggest an early epoch of deceleration, but this is too important a conclusion to rest on just one object. Here we propose to use HST for observations of six SNe Ia in the range 1.2 <= z <= 1.6, that will be discovered as a byproduct from proposed Treasury programs for high-latitude ACS surveys. Six objects will provide a much firmer foundation for a conclusion that touches on important questions of fundamental physics. ACS 9411 Morphologies and faint neighbors of z=4.5 Lyman Alpha Emitting Galaxies We propose to image one ACS field containing four spectroscopically confirmed Ly-alpha emitters at z=4.5 in restframe UV and a narrowband filter containing the Ly-alpha line. These observations will {A} Reveal the morphology of the four spectroscopically confirmed sources. The high equivalent widths of the Ly-alpha line in these four galaxies in particular and this population in general cannot be explained without invoking one or more of: extreme youth of the stellar population, zero metallicity, energetic winds or type II quasars. Comparison of morphologies in the line and continuum would help favor or rule out some of these possibilties. This would also tell us whether the star-formation is uniformly distributed or centrally concentrated or concentrated but in many clumps? Proximity of these galaxies {average projected physical separation of 200 kpc, with one pair 30 kpc apart} also makes interactions likely. {B} Extend the luminosity function of Ly-alpha sources by 2.5 magnitudes due to better spatial resolution of HST and sensitivity of ACS. We will be able to detect sources with line flux of ~eq 2 * 10^-18 ergcm2s over 11.5 sq-arcmins {~ 100 sources}. This complements the LALA {Large Area Lyman Alpha} survey which covers 1/3 square-degree to a line sensitivity of ~eq 2 * 10^- 17. Thus we get a picture of this patch of young universe in two ways: statistics of faint galaxies and morphologies of relatively bright ones. ACS 9472 A Snapshot Survey for Gravitational Lenses among z >= 4.0 Quasars Over the last few years, the Sloan Digital Sky Survey has revolutionized the study of high-redshift quasars by discovering over 200 objects with redshift greater than 4.0, more than doubling the number known in this redshift interval. The sample includes eight of the ten highest redshift quasars known. We propose a snapshot imaging survey of a well-defined sample of 250 z > 4.0 quasars in order to find objects which are gravitationally lensed. Lensing models including magnification bias predict that at least 4% of quasars in a flux-limited sample at z > 4 will be multiply lensed. Therefore this survey should find of order 10 lensed quasars at high redshift; only one gravitationally lensed quasar is currently known at z > 4. This survey will provide by far the best sample to date of high-redshift gravitational lenses. The observed fraction of lenses can put strong constraints on cosmological models, in particular on the cosmological constant Lambda. In addition, magnification bias can significantly bias estimates of the luminosity function of quasars and the evolution thereof; this work will constrain how important an effect this is, and thereby give us a better understanding of the evolution of quasars and black holes at early epochs, as well as constrain models for black hole formation. ACS 9480 Cosmic Shear With ACS Pure Parallels Small distortions in the shapes of background galaxies by foreground mass provide a powerful method of directly measuring the amount and distribution of dark matter. Several groups have recently detected this weak lensing by large-scale structure, also called cosmic shear. The high resolution and sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear accurately on small scales. Using 260 parallel orbits in Sloan textiti {F775W} we will measure for the first time: beginlistosetlength sep0cm setlengthemsep0cm setlength opsep0cm em the cosmic shear variance on scales <0.7 arcmin, em the skewness of the shear distribution, and em the magnification effect. endlist Our measurements will determine the amplitude of the mass power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density Omega_m with s/n=4. They will be done at small angular scales where non-linear effects dominate the power spectrum, providing a test of the gravitational instability paradigm for structure formation. Measurements on these scales are not possible from the ground, because of the systematic effects induced by PSF smearing from seeing. Having many independent lines of sight reduces the uncertainty due to cosmic variance, making parallel observations ideal. ACS/WFPC2 9481 Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS Survey Fields In anticipation of the allocation of ACS high-latitude imaging survey{s}, we request a modification of the default pure parallel program for those WFPC2 parallels that fall within the ACS survey field. Rather than duplicate the red bands which will be done much better with ACS, we propose to observe in the near-ultraviolet F300W filter. These data will enable study of the rest-frame ultraviolet morphology of galaxies at 0<z<1. We will determine the morphological k-correction, and the location of star formation within galaxies, using a sample that is likely to be nearly complete with multi-wavelength photometry and spectroscopic redshifts. The results can be used to interpret observations of higher redshift galaxies by ACS. ACS/WFPC2 9488 Cosmic Shear - with ACS Pure Parallel Observations The ACS, with greater sensitivity and sky coverage, will extend our ability to measure the weak gravitational lensing of galaxy images caused by the large scale distribution of dark matter. We propose to use the ACS in pure parallel {non- proprietary} mode, following the guidelines of the ACS Default Pure Parallel Program. Using the HST Medium Deep Survey WFPC2 database we have measured cosmic shear at arc-min angular scales. The MDS image parameters, in particular the galaxy orientations and axis ratios, are such that any residual corrections due to errors in the PSF or jitter are much smaller than the measured signal. This situation is in stark contrast with ground-based observations. We have also developed a statistical analysis procedure to derive unbiased estimates of cosmic shear from a large number of fields, each of which has a very small number of galaxies. We have therefore set the stage for measurements with the ACS at fainter apparent magnitudes and smaller, 10 arc-second scales corresponding to larger cosmological distances. We will adapt existing MDS WFPC2 maximum likelihood galaxy image analysis algorithms to work with the ACS. The analysis would also yield an online database similar to that in archive.stsci.edu/mds/ ACS/WFC 9575 Default {Archival} Pure Parallel Program. The Advanced Camera for Surveys (WFC) was used to test ACS pure parallels in POMS. WFPC2 9589 WFPC2 Decontaminations and Associated Observations Pt. 1/3 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 9594 WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt2/3 This dark calibration program obtains 3 dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels STIS 9605 CCD Dark Monitor-Part 1 Monitor the darks for the STIS CCD STIS 9607 CCD Bias Monitor - Part 1 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 9615 Cycle 11 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. ACS 9673 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 STIS 9706 STIS Pure Parallel Imaging Program: Cycle 10 This is the default archival pure parallel program for STIS during cycle 10. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 8927: During ZOE @ 042/21:22:04Z, GS Acquisition (2,0,2) failed. At AOS, in FN format and FGS 1 was taking astrometry. The guide star acquisition for this observation was non-nominal, further analysis will determine if a repeat observation is required. COMPLETED OPS REQs: NONE OPS NOTES EXECUTED: 911-0 Limit Management During WFPC2 Decontamination (M001) (ULIMTECF) @ 042/20:16z 911-0 Limit Management During WFPC2 Decontamination (M001) (ULIMTECN) @ 043/06:47z

                         SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq             11                       10       See Hstar # 8927
FGS REacq              3                         3
FHST Update           23                        23
LOSS of LOCK

Thursday, February 13, 2003
Source: Space Telescope Science Institute