Status Report

Hubble Space Telescope Daily Report #2805 02/09/01

By SpaceRef Editor
February 9, 2001
Filed under ,

PERIOD COVERED:  0000Z (UTC) 02/08/01 – 0000Z (UTC) 02/09/01
Daily Status Report as of 040/0000Z
    1.1 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.
    1.2 Completed Four Sets of WF/PC-2 8827 (Cycle 9 Supplemental Darks pt2/3)
        The WF/PC-2 was used to obtain three dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels.  The proposal completed nominally.
    1.3 Completed STIS/CCD/MA2 8673 (The Properties of Ly-Alpha Absorbers at Redshifts Between 0.9HST)
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used obtain new Echelle resolution spectra of three bright quasars which, when combined with archived and scheduled observations, will be used to characterize the properties of Ly-Alpha absorbers in the redshift range 0.9<z<1.6.  There were no reported problems.
    1.4 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 Group.  The proposal completed with no reported problems.
    1.5 Completed STIS/CCD/MA1 8662 (A Snapshot Survey of the Hot Interstellar Medium)
        The Space Telescope Imaging Spectrograph (CCD And MA1) was used to obtain snapshot STIS echelle observations of key tracers of hot interstellar gas {C IV, N IV, and Si IV} for selected FUSE Team O VI survey targets with known UV fluxes.  By taking advantage of the snapshot observing mode we will efficiently obtain a large number of spectra suitable for the study of the highly ionized hot component of the interstellar medium {ISM}.  Our goals are to explore the physical conditions in and distribution of such gas, as well as to explore the nature of the interfaces between the hot ISM and the other interstellar gas phases.  The observations completed with no reported problems.
    1.6 Completed WF/PC-2 8597 (The Fueling of Active Nuclei: Why are Active Galaxies Active?)
        The WF/PC-2 was used to investigate the accretion onto massive black holes that are believed to be the energy source for AGN.  However, evidence for black holes in quiescent galaxies has also been reported.  Why are these galaxies inactive?  One possibility is that active galaxies are better at providing fuel to the nuclear region than quiescent
galaxies.  Other possible fueling mechanisms such as “bars-within-bars” or nuclear spirals cannot be investigated from the ground because they are relatively small features in the ISM.  The observations were completed as planned.
    1.7 Completed Four Sets of STIS/CCD 8562 (Probing the Large Scale Structure: Cosmic Shear Observations)
        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.
    1.8 Completed STIS/CCD/MA2 8770 (The Nucleosynthesis of Boron – Benchmarks for the Galactic Disk)
        The Space Telescope Imaging Spectrograph (CCD and MA2) was used to determine boron (B) abundance.  In spite of several HST cycles of B abundance determinations, we do not know the true, ambient, present-day abundance of B.  Only two stars {with undepleted Li and Be} have been observed to derive the Population I true B abundance.  Past cycles have focused on {1} halo stars with low metallicity and {2} solar-type stars with Li and/or Be deficiencies.  In this proposal, the stellar abundances of B will be determined, measured from the B I 2497 Angstrom line from STIS echelle spectra, of main sequence F-G stars that have retained their full initial abundances of boron.  Our target stars are those for which ground-based observations show that beryllium is undepleted.  These new abundances will map evolution of the B abundance in the Galactic disk in the metallicity range from one-third solar up to solar.  Then the B, and previously determined Li and Be abundances, will be used to improve understanding of the nucleosynthesis of B.  There were no reported anomalies.
    1.9 Completed WF/PC-2 8587 (Stroemgren Photometry of Globular Clusters in M87: Breaking the Age- Metallicity Degeneracy)
        The WF/PC-2 was used to further demonstrate that the globular cluster {GC} systems of most, and possibly all, luminous galaxies show bimodal distributions in broadband color and, by implication, age and/or metallicity.  Whatever its origin, this bimodality {which is observed in giant galaxies that span a wide range in Hubble Type and local environment} must hold a fundamental clue to the process of galaxy formation.  The technique of this proposal hinges on the ability of Stroemgren photometry to decouple the effects of age and metallicity for large samples of GCs, and will provide the first strong constraints on the various galaxy formation models.  There were no reported problems.
    1.10 Completed STIS/CCD 8855 (Slit Wheel Repeatability)
        The Space Telescope Imaging Spectrograph (CCD) was used to test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}.  The proposal completed nominally.
    1.11 Completed WF/PC-2/STIS/CCD 8679 (Constraining the Age of the Oldest Stars from the White Dwarf Cooling Sequence in M4)
        The WF/PC-2 and the Space Telescope Imaging Spectrograph (CCD) were used to search for the oldest and hence coolest white dwarfs {WDs} in M4, the nearest Galactic globular cluster to the Sun.  New models for cooling hydrogen white dwarfs predict that their colors should become bluer, rather than redder, with increasing age. The goal is to test these models and at the same time constrain the age of M4.  The proposal completed with no problems.
    2.1 Guide Star Acquisitions:
      Scheduled Acquisitions:  8
Successful:  8
  Scheduled Re-acquisitions:  8
Successful:  8
    2.2 FHST Updates:
Scheduled: 18
Successful: 18
    2.3 Operations Notes:
        The SSR EDAC error counter was cleared four times per ROP SR-1A.
        Using ROP NS-5, SI C&DH errors were reset at 039/1937Z.
        An engineering status buffer error was reset at 039/2125Z as directed by ROP DF-18A.
        Per ROP IC-2, SSA transmitter #1 was turned on and off for the interval 039/2355Z to 040/0023Z.
        Continuation of normal science observations and calibrations.

SpaceRef staff editor.