Status Report

Hubble Space Telescope Report #2715 09/26/00

By SpaceRef Editor
September 26, 2000
Filed under

PERIOD COVERED:  0000Z (UTC) 09/25/00 – 0000Z (UTC) 09/26/00
Daily Status Report as of 270/0000Z
    1.1 Completed WF/PC-2 8683 (Imaging Of Brightest Cluster Galaxies: The High End Of The Black Hole Mass Distribution)
        The WF/PC-2 was used to make kinematic black hole detections in galaxies to decide whether they indicate that the mass correlates with both optical luminosity and radio power.  The observation completed with no reported problems.
    1.2 Completed Three Sets of STIS/CCD 8562 (Probing the Large Scale Structure: Cosmic Shear Observations) HST
        The Space Telescope Imaging Spectrograph (CCD) was used to probe the distortion of light bundles from distant galaxies, looking at the statistical properties of the intervening inhomogeneous {dark} matter distribution.  The proposal completed nominally.
    1.3 Completed STIS/CCD/MA1 8304 (Stellar Winds from Central Stars of Young Planetary Nebulae)
        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to observe stellar winds from central stars of planetary nebulae that are responsible for driving the dynamical expansion as well as shaping the morphology of planetary nebulae.  The observations completed with no reported anomalies.
    1.4 Completed WF/PC-2 8816 (Cycle 9 UV Earthflats)
        The WF/PC-2 was used to obtain sequences of earth streak flats to improve the quality of pipeline flat fields for the WFPC2 UV filter set and in order to monitor flat field stability.  There were no reported problems.
    1.5 Completed Three Sets of WF/PC-2 8805 (POMS Test Proposal: WFII Parallel Archive Proposal Continuation)
        The WF/PC-2 was used to perform a 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 Parallels Working.  The proposal completed with no reported problems.
    1.6 Completed Two Sets of WF/PC-2 8826 (Cycle 9 Supplemental Darks pt 1)
        The WF/PC-2 was used to perform a T dark calibration program that obtains three dark frames every day in order to provide data for monitoring and characterizing the evolution of hot pixels.  There were no reported anomalies.
    1.7 Completed STIS/CCD/MA2 8569 (A New Survey for Low-Redshift Damped Lyman-Alpha Lines in QSO MgII Systems)
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to support studies which have shown that most of the observable neutral gas mass in the Universe resides in QSO damped LyAlpha {DLA} systems.  However, at low redshift , DLA can only be found by searching in the UV with HST.  By boot-strapping from the MgII statistics, we will be able to further improve the determination of the low- redshift statistical properties of DLA {their incidence and cosmological mass density} and open up new opportunities for studies at low redshift.  The observations completed nominally.
    1.8 Completed Four Sets of STIS/MA2 8426 (Cycle 8 MAMA Dark Measurements)
        The Space Telescope Imaging Spectrograph (MA2) was used to make a routine Cycle-8 MAMA dark noise calibration measurement.  This proposal will provide the primary means of checking on the health of the MAMA detectors.  This is done through frequent monitoring of the background count rate.  The observations were completed as planned, and no problems were reported.
    1.9 Completed WF/PC-2 8632 (A UV Atlas of Nearby Galaxies)
        The WF/PC-2 was used to perform a snapshot survey of local galaxies at UV wavelengths with the F300W filter.  The aim of the project is to build a reference UV Atlas of normal galaxies, whose optical images are well known, with the highest possible degree of information, covering all the morphological types and luminosity classes.  The proposal completed normally.
    1.10 Completed WF/PC-2 8812 (Cycle 9 Internal Monitor)
        The WF/PC-2 was used to obtain routine internal monitors for WFPC2 in order 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.  There were no reported problems
    1.11 Completed STIS/CCD/MA1 8287 (A Search For Transparent Lines of Sight With Intergalactic He-II Absorption Towards 26 Bright z > 2.9 Quasars)
        The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make He-II absorption line observations of quasar HE2250-371.  The aim is to identify more suitable bright objects for detailed studies of intergalactic He-II absorption at a redshift of Z <2.9 and >3.2 .  A wavelength calibration observation was also taken.  The observations were executed as scheduled, and no anomalies were noted.
    1.12 Completed WF/PC-2 8804 (A Survey of Gravitational Lenses as Cosmological Tools III)
        The WF/PC-2 was used to observe 60 known gravitational lenses that are a unique, mass-selected sample of galaxies, and their properties encode an enormous range of astrophysical information.  The numbers of lenses and their distribution in separation, lens and source redshift determine both the cosmological model and the mass function of galaxies and its evolution.  There were no reported problems.
    1.13 Completed Two Sets of STIS/CCD 8837 (CCD Dark Monitor-Part 1)
        The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks.  The proposal completed with no reported problems.
    1.14 Completed WF/PC-2 8698 (Identification of the Galaxy’s Missing Mass)
        The WF/PC-2 was used to observe the nature of dark matter that is one of the key astrophysical questions of the day.  The existence of dark matter and its dynamical dominance in the outer parts of our Galaxy and spiral galaxies with flat rotation curves is well established.  The MACHO project has identified ~half of the Milky Way’s dark matter with stellar objects of ~0.5 M_sun, probably white dwarfs.  But the location of the microlensing in the halo is disputed.  Several have detected two candidate halo white dwarfs of L/L_sun ~ 10^-5 in the Hubble Deep Field with 25 +/- 5 mas/year proper motions.  The observations completed with no reported problems.
    1.15 Completed STIS/CCD 8838 (Bias Monitor – Part 1)
        The Space Telescope Imaging Spectrograph (CCD) was used to monitor the bias in the 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1, and 1×1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns.  The proposal completed nominally.
    1.16 Completed STIS/CCD 8870 (POMS Test Proposal: STIS Non-Scripted Parallel Proposal Continuation IV)
        The Space Telescope Imaging Spectrograph (CCD) was used to make non-scripted, parallel observations as part of a POMS test proposal.  The observations completed with no anomalous activity.
    1.17 Completed STIS/CCD 8603 (Secular Changes In The Temperatures And Radii Of Extreme Helium Stars)
        The Space Telescope Imaging Spectrograph (CCD) was used to make observations of 15 extreme helium stars (EHEs_ which, together with IUE data, will give a 20-year baseline of ultraviolet spectrophotometry.  EHEs are luminous stellar remnants evolving rapidly to become white
dwarfs.  They represent an important stage in the evolution of at least some low-mass stars, and are closely related to the R Coronae Borealis variables.  Models do not agree about their origin, nor about what fraction of normal stars pass through this phase, in which the stars have been completely stripped of their outer layers.  The models do predict that EHEs are contracting and provide rate predictions and evolutionary
lifetimes.  The observations completed with no reported problems.
    1.18 Completed STIS/CCD 8700 (A STIS Spectroscopic Snapshot Survey of 3CR Radio Galaxies : The Nature of the Unresolved Nuclei)
        The Space Telescope Imaging Spectrograph (CCD) was used to perform STIS snapshot long-slit spectroscopy of these nuclei over 2900- 10300 AA to classify them {QSO, NLRG, BLRG, BL Lac, ldots} and establish their AGN characteristics down to the lowest nuclear luminosities, while still within powerful 3C radio galaxies.  The primary goals are : {1} to test unification schemes by identifying previously undetected signatures of low-level AGN/QSO activity in their spectra in the form of weak, broad emission lines, featureless continua, and UV excess, {2} to constrain the FR I/BL Lac connection by measuring the relative contribution of thermal {starburst}, non-thermal {optical synchrotron}, and line emission, and {3} to perform line and continuum diagnostics to determine the dominant ionization mechanisms in the circumnuclear regions {tenths of arcseconds} and the role of dust extinction in the NLRGs and BLRGs in the form of geometrically thick or thin tori and foreground dust.  The proposal completed as planned, with no reported anomalies.
    1.19 Completed WF/PC-2 8544 (POMS Test Proposal: WFII Backup Parallel Archive Proposal II)
        The WF/PC-2 was used to execute a POMS test proposal that was designed to simulate scientific plans.  No problems were encountered
    1.20 Completed STIS/CCD 8664 (Structural Measurement of Globular Clusters in M31 and NGC 5128: Stalking the Fundamental Plane)
        The Space Telescope Imaging Spectrograph (CCD) was used to observe in the snapshot mode to image a wide selection of individual globular clusters in two other large galaxies {M31 and NGC 5128} for measurement of their structural parameters {r_c, c, central surface brightness}.  We will use these to compute their binding energies and define the FP in these two galaxies. Comparison with the Milky Way will then give us powerful new information on just how “universal” the cluster formation process was in the early protogalaxies.  The observations completed with no reported problems.
    1.21 Completed STIS/CCD/MA2 8621 (The Galactic Abundance Gradients of Boron and Iron)
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to provide the first measurement of the Galactic abundance gradients for Boron and Iron.  Boron abundances were obtained for 5 B-type stars {with Galactocentric distances between 4-15 kpc} from the BIII 2066 Angstrom line.  Optical spectroscopy of these {and other B-type} stars has yielded abundance gradients of -0.07 dex/kpc for N & the Alpha-elements {O, Mg, Si}.  Determination of Boron abundances require UV spectra.  The proposal completed nominally.
    2.1 Guide Star Acquisitions:
      Scheduled Acquisitions:  6
                Successful:  6
    Scheduled Re-acquisitions: 11
                Successful: 11
    2.2 FHST Updates:
                  Scheduled: 13
                Successful: 13
    2.3 Operations Notes:
        Using ROP DF-18A, the 486 engineering status buffer was dumped and cleared at 269/1108Z.
        SSA transmitter #2 was turned on at 269/1823Z and off at 269/1905Z per ROP IC-2.
        Continuation of normal science observations and calibrations.

SpaceRef staff editor.