HUBBLE SPACE TELESCOPE DAILY REPORT # 3176 PERIOD COVERED: DOY 221-223 OBSERVATIONS SCHEDULED (see HSTARS below for possible observation problems) WFPC2 9676 POMS Test Proposal: WFII parallel archive proposal This is the generic target version of the WFPC2 Archival Pure Parallel= program. The program will be used to take parallel images of random areas of the sky, following the recommendations of the 2002 Parallels Working Group. ACS 9472 A Snapshot Survey for Gravitational Lenses among z >=3D 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=20 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=20 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=20 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=20 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.=20 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=3D4. 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 9665 Extreme Red Stars ACS provides unprecedented sensitivity in the far red, this coupled with= recent astronomical pushes to ever cooler objects {e.g. new classifications for L= =20 and T stellar dwarfs, and extremely high redshift galaxies} increases the need for extending the photometric calibration to include such objects. We propose observations of 4 stellar objects for which excellent ground based optical= and near-IR data exist that span V-I colors of 4.5 at M7 to > 6.0 at L5. ACS 9395 Is Bulge Formation Still Going-On? An ACS Survey of Pseudo-Bulges Pseudo-bulges, i.e., bulges with an exponential light profile, have been unveiled in the centers of many intermediate-type disks. Their structural similarity with the disks provides support to theoretical scenarios in which bulges may form due to secular evolution processes within the host disks. If= at play, these processes would likely be active throughout a large fraction of cosmic history down to our days: `young' bulges should exist. Our previous= HST WFPC2 and NICMOS survey of ~100 spirals has provided V-H colors for 11 Sb-Sc pseudo-bulges, and these could be interpreted as suggestive of relatively= young stellar ages. Furthermore, dense nuclei have been discovered in these pseudo-bulges, and their V-H colors may imply stellar masses sufficiently= large to activate the formation of the pseudo- bulge by means of dynamical=20 dissolution of progenitor bars. However, the V-H color, on its own, is fully degenerate towards stellar ages, metallicities and masses, as well as dust content. We therefore propose to use ACS to observe the 11 pseudo-bulges of our combined WFPC2 and NICMOS sample in the F330W, F435W, and F814W filters. Extending= the wavelength baseline to the bluer passbands is essential to break the mass-age-metallicity-dust degeneracy, and will provide far more accurate estimates for the stellar population properties of the pseudo-bulges and= their nuclei. Proving the existence of `young' bulges in the local Universe would= =20 have a big impact in our understanding of the formation of the Hubble sequence. ACS 9563 Preliminary ACS Sensitivity A spectrophotometric standard star is observed through a popular subset of filters of each camera to assess the sensitivity of the instrument. The star= is placed at the centre of the aperture, and two images are taken through each filter. This programme is based on proposal 9020 designed for SMOV. There= are three groups of visits, numbered respectively 1 through 3, 4 through 6 and 7 through 9. The three visits in each group must be executed about one month= =20 apart from one another, as indicated in the visit requirements. The first visit in each group {namely visits 1, 4 and 7} ought to be scheduled during the month= of July 2002. During SMOV the standard star GD71 could be used, which is not visible during the Cycle 11 interim calibration period. We have selected GRW+705824 instead. The latter is a WD slightly brighter than GD71 in V but= =20 with very similar spectral properties. The exposure times with this object have= been selected to reach, on average, SNR~350 in the central pixel for broad band filters. ACS 9425 The Great Observatories Origins Deep Survey: Imaging with ACS We propose a Treasury program of ACS imaging as part of the Great= Observatories Origins Deep Survey {GOODS}, covering 320{square}', or 32* the area of the= two original WFPC2 HDFs, to within 0.5--0.8 mag of their depth in four ACS= bands, BViz. The two GOODS fields, the Hubble Deep Field North and Chandra Deep= Field South, are the premier deep survey areas from X-- ray to radio wavelengths.= ACS data will provide unique angular resolution, sensitivity, and wavelength coverage to close the gap between the deepest Chandra and SIRTF= observations. Supported by extensive imaging and spectroscopy from the VLT, Keck, Subaru, NOAO, Gemini, VLA, JCMT, and other facilities, the combined GOODS data set= will make it possible to map the evolution of the Hubble sequence with redshift, reconstruct the history of galaxy mass assembly, star formation and nuclear activity from the epoch of reionization to the present, trace the growth of density perturbations via cosmic shear, and, with properly phased z--band observations, detect ~ 12 Type Ia supernovae at 1.2 10^10=20 M_odot of molecular hydrogen compressed into their central few kpc. With the ACS= High Resolution Camera we will obtain deep UBVI imaging of the active central=20 regions of these galaxies, allowing us to trace the luminosities, colors, masses,= and ages of the young star clusters within them. ACS/CAL 9558 ACS weekly Test This program consists of basic tests to monitor, the read noise, the=20 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 9379 Near Ultraviolet Imaging of Seyfert Galaxies: Understanding the= Starburst-AGN Connection We propose a near-UV snapshot survey of 101 Seyfert galaxies using ACS/HRC= and the filter F330W, a configuration which is optimal to detect faint star= forming regions around their nuclei. These images will complement optical and= near-IR images available in the HST archive, thus providing a panchromatic atlas of= the inner regions of active galaxies, which we will use to study the= starburst-AGN connection. The main goals of this proposal are: {1} Determine the frequency= of circumnuclear starbursts in Seyferts, down to levels which cannot be= observed from the ground; {2} characterize the observational {fluxes, colors,= structure, sizes} and intrinsic {luminosities, masses, ages, global star-formation= rate} properties of these clusters; {3} derive the luminosity functions of young= star clusters around the nucleus of Seyferts and compare these results with those from normal and starburst galaxies to determine their survival rate close=20 to the AGN; {4} address questions about the relation between AGNs and starbursts,= like the possible connection between the masses and luminosities of black holes= and starbursts, and the implications for the evolution of the black holes and= their host galaxy bulges. By adding UV images to the existing optical and near-IR ones, this project will create an extremely valuable database for= astronomers with a broad range of scientific interests, from the properties of the AGN= to the properties of their host galaxies. ACS/WFC/HRC 9562 Cycle 11 Internal Flat Field Stability. The Advance Camera for Surveys (WFC and HRC) was used to obtain flat field stability and characterization samples of the ACS filter set. Only internal exposures using the calibration lamps were required. 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/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