NASA Hubble Space Telescope Daily Report #3936

Status Report From: Space Telescope Science Institute
Posted: Thursday, September 1, 2005


HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science


PERIOD COVERED: UT August 31, 2005 (DOY 243)


ACS/HRC 10458

ACS and WFPC2 TGSMOV Two-Gyro PSF, Pointing, and Dither Test

12 orbits allocated. Currently only 7 orbits scheduled in this proposal version. Other visits / orbits may be added pending results of F2G test and managerial decisions. This version contains ACS/HRC with parallels in ACS/WFC and NICMOS. No WFPC2 in this version. Goals: PSF, PSF repeatability, pointing and stability within orbit and between orbits. Also test results for different targets. {F2G requirements 1a, 1c, 2 ,4}


ACS CCDs daily monitor - Cycle 13 - Part 2

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 program will be for the entire lifetime of ACS.


Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have relatively fragile test particles which can be used as tracers of the early dynamical evolution of the outer Solar System. We propose a Snapshot program using the ACS/HRC that has a potential discovery efficiency an order of magnitude higher than the HST observations that have already discovered the majority of known transneptunian binaries. By more than doubling the number of observed objects in dynamically hot and cold subpopulations we will be able to answer, with statistical significance, the question of whether these groups differ in the abundance of binaries as a result of their particular dynamical paths into the Kuiper Belt. Today's Kuiper Belt bears the imprints of the final stages of giant-planet building and migration; binaries may offer some of the best preserved evidence of that long-ago era.

ACS/WFC 10597

Resolving the Connection Between Globular Clusters and Low-Mass X-ray Binaries

Because of their high central densities, globular clusters {GCs} are efficient producers of low- mass X-ray binaries {LMXBs}. To shed light on the detailed formation mechanism of LXMBs in GCs, we propose to measure accurate structural parameters for hundreds of GCs in NGC 5128: the only giant elliptical galaxy within 5 Mpc of the Milky Way. We will carry out the first complete survey of GCs in the inner region of NGC 5128, measure GC structural parameters of unprecedented acccuracy, and derive GC luminosity profiles in the cluster cores. These measurement will allow us to determine precisely which GC structural properties control the presence of an X-ray source and thus probe the details of the LXMB formation process in GCs. We will additionally use the measured structural parameters to perform the most comprehensive study of the fundamental plane of GCs in early-type galaxies, a fundamental set of correlations which holds key information on GC formation and evolution.


Probing Evolution And Reionization Spectroscopically {PEARS}

While imaging with HST has gone deep enough to probe the highest redshifts, e.g. the GOODS survey and the Ultra Deep Field, spectroscopic identifications have not kept up. We propose an ACS grism survey to get slitless spectra of all sources in a wide survey region {8 ACS fields} up to z =27.0 magnitude, and an ultradeep field in the HUDF reaching sources up to z =28 magnitude. The PEARS survey will: {1} Find and spectrocopically confirm all galaxies between z=4-7. {2} Probe the reionization epoch by robustly determining the luminosity function of galaxies and low luminosity AGNs at z = 4 - 6. With known redshifts, we can get a local measure of star formation and ionization rate in case reionization is inhomogeneous. {3} Study galaxy formation and evolution by finding galaxies in a contiguous redshift range between 4 < z < 7, and black hole evolution through a census of low-luminosity AGNs. {4} Get a robust census of galaxies with old stellar populations at 1 < z < 2.5, invaluable for checking consistency with heirarchical models of galaxy formation. Fitting these galaxies' spectra will yield age and metallicity estimates. {5} Study star-formation and galaxy assembly at its peak at 1< z < 2 by identifying emission lines in star-forming galaxies, old populations showing the 4000A break, and any combination of the two. {6} Constrain faint white dwarfs in the Galactic halo and thus measure their contribution to the dark matter halo. {7} Derive spectro-photometric redshifts by using the grism spectra along with broadband data. This will be the deepest unbiased spectroscopy yet, and will enhance the value of the multiwavelength data in UDF and the GOODS fields to the astronomical community. To this end we will deliver reduced spectra to the HST archives.

FGS 10610

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

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.

WFPC2 10534

Active Atmospheres on Uranus and Neptune

We propose Snapshot observations of Uranus and Neptune to monitor changes in their atmospheres on time scales of weeks, months, and years. Uranus is rapidly approaching equinox in 2007, with another 4 degrees of latitude becoming visible every year. Recent HST observations during this epoch {including 6818: Hammel, Lockwood, and Rages; 8680: Hammel, Rages, Lockwood, and Marley; 8634: Rages, Hammel, Lockwood, Marley, and McKay; and 10170: Rages, Hammel, Lockwood, and Marley} have revealed strongly wavelength-dependent latitudinal structure and the presence of numerous visible-wavelength cloud features in the northern hemisphere. Long-term ground-based observations {Lockwood and Thompson 1999} show seasonal brightness changes whose origins are not well understood. Recent near-IR images of Neptune obtained using adaptive optics on the Keck Telesccope together with images from our Cycle 9 Snapshot program {8634} show a general increase in activity at south temperate latitudes as well as the possible development of another Great Dark Spot. Further Snapshot observations of these two dynamic planets will elucidate the nature of long-term changes in their zonal atmospheric bands and clarify the processes of formation, evolution, and dissipation of discrete albedo features.


Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.)


9930 - GSAcq(2,3,3) requires 2 attempts to achieve CT-DV @ 239/1412z

OTA SE review of PTAS TC processing log for the 234P SMS reveal that the GSAcq(2,3,3) at 239/14:10:10 took 2 attempts in CT before achieving CT-DV on FGS1.

9931 - GSAcq(1,2,1) failed due to search radius limit exceeded @ 244/0506z

OBAD @ 244/05:00:53 showed the following errors: 10.03, 0.00, 13.57, 22.48. OBAD @ 244/05:13:27 showed the following errors: 2.07, 0.00, -1.67, 2.66

9932 - ReAcq (1,2,1) failed due to search radius limit exceeded @ 244/0640z

OBAD @ 244/06:30:25 showed the following errors: 6.20, 15.64, -13.18, 21.37


17533-2 - TMDIAG for VehConLaw.IntegralPath[2] @ 243/2156z


DF-18A - ESB Error '1805'; (T2G_MOVING_TARGET_DETECTED); SESBSLD H/L Limit = 1 @ 243/0939z

DF-18A - ESB Error '1805'; (T2G_MOVING_TARGET_DETECTED); SESBSLD H/L Limit = 2 @ 244/0337z

DF-18A - ESB Error '1805'; (T2G_MOVING_TARGET_DETECTED); SESBSLD H/L Limit = 3 @ 244/0457z

DF-18A - ESB Error '1805'; (T2G_MOVING_TARGET_DETECTED); SESBSLD H/L Limit = 4 @ 244/0459z

                               SCHEDULED     SUCCESSFUL    FAILURE TIMES
Gsacq                   12                       11              244/0506z; 
HSTAR 9931
FGS Reacq                    3                         2              39 
244/0640z; HSTAR 9932
OBAD with Maneuver     30                        30

FAD from OBAD with No Maneuver - 7


A detailed review of the science data obtained since Monday's entry into Two Gyro Science mode has been performed. The teams have verified the ACS PSF and coronagraphy, NICMOS PSF and coronagraphy, and the observation of a moving target (Mars) with ACS. All science targets have been acquired, with all successful FHST attitude corrections and FGS guide star acquisitions. HST's science capability in TGS matches that seen in the February TGS on-orbit test, and cannot be distinguished from that of three gyro operations. Operations and science planning have now returned to the regular schedule for command load preparations.

On-board Attitude Determination (OBAD) error correction pairs statistics:

#1 OBAD 0.12 degrees, 4.42 degrees, average 1.04

#2 OBAD 1.18 arcseconds, 42.75 arcseconds, average 9.66

Boresight jitter: 5 mas or below

// end //

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