HUBBLE SPACE TELESCOPE

   DAILY REPORT #2879

PERIOD COVERED:  0000Z (UTC) 05/23/01 - 0000Z (UTC) 05/24/01

Daily Status Report as of 144/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

    1.1 Completed WF/PC-2 9144 (Calibrating Star Formation: The Impact of 
Environment)

        The WF/PC-2 was used to obtain UV, V, and I broad-band and HAlpha, 
OIII, SII, and HBeta emission line images of three nearby, starburst 
galaxies to: map the young stellar populations and star clusters, locate 
the obscuring dust clouds, and diagnose conditions in the ionized ISM.  The 
sample is carefully selected to probe a range of environments for the host 
galaxy, from isolated to group-interacting, for constant morphology, 
luminosity and metallicity.  The galaxies are all closer than ~4 Mpc, 
giving ~2 pc resolution with the WF so we can chart the detailed structure 
of each starburst.  This project is designed to: {a} establish whether 
starbursts are large-scale coherent or chaotic processes by investigating 
the presence of sequential/propagating star formation; and {b} explore the 
influence of the external environment on the evolution of the 
starburst.  For this purpose we will measure: {1} the recent star formation 
history of both stellar clusters and young diffuse population; {2} the dust 
distribution; and {3} the structures in the shocked and photo-ionized 
gas.  This study will provide a physical basis, in terms of energetics, 
evolution, and internal structures, for the interpretation of blue galaxies 
at intermediate and high redshifts. No problems were reported.

    1.2 Completed WF/PC-2 9173 (The Pattern of Heavy Element Abundances in 
a Damped LyAlpha Galaxy)

        The WF/PC-2 was used to observe the quasar PKS 1127-143.  X-ray 
absorption associated with an intervening 21-cm and damped LyAlpha$ 
absorber at z=0.312 in its spectrum has been detected with Chandra.  The 
advantage of the X- ray measurement is that the derived metallicity is 
insensitive to ionization, inclusion of an atom in a molecule, or depletion 
onto grains.  The X-ray absorption is mostly due to oxygen, and the 
abundance agrees with the oxygen abundance of 16-40 lines in a galaxy at 
the redshift of the absorber.  The STIS spectrum will allow measurement 
of  Zn II, an undepleted iron peak element.  Comparison of the oxygen group 
measured in the X-rays with the iron peak nuclei measured will reveal 
whether the absorber has a Pop II, halo-type abundance pattern or a Pop I, 
disk-like abundance pattern.  The proposla completed with no reported 
anomalous activity.

    1.3 Completed WF/PC-2 9045 (The Relationship Between Radio Luminosity 
and Radio-Loud AGN Host Galaxy Properties)

        The Wf/PC-2 was used to determine the relationship between the 
properties of the host galaxies of radio-loud AGN and their radio 
luminosities.  Previous studies in this area with the HST have concentrated 
on the 3C sample which shows a tight correlation between luminosity and 
redshift, such that evolutionary effects cannot be distinguished from those 
depending upon radio luminosity.  Our sample of 46 radio galaxies at z ~ 
0.5 comes from four complete, low-frequency-selected samples of radio 
sources with differing flux limits.  Thus the total sample spans an 
unprecedented three orders of magnitude in radio luminosity at a fixed 
redshift interval.  The proposal completed with no reported problems.

    1.4 Completed WF/PC-2 9085 (Measuring The Masses Of High-Z Quasar Host 
Galaxies)

        The WF/PC-2 was used to investigate the close link between 
black-hole mass and spheroid mass in both quiescent and active galaxies in 
the local universe.  Consequently black-hole and spheroid formation/growth 
are now viewed as intimately related processes, and establishing the mass 
of quasar host galaxies as a function of redshift is now seen as a key 
measurement in observational cosmology.  From the Cycle 7 NICMOS program, 
the best estimate to date of the mass evolution of the hosts of both 
radio-quiet and radio-loud quasars out to z ~eq 2 has been derived.  Under 
the assumption of passive stellar-population evolution our results are 
consistent with the black-hole/spheroid population being unchanged out to z 
~eq 2.  However, the crucial assumption of passive evolution needs to be 
tested.  All observations competed nominally.

    1.5 Completed Two Sets of WF/PC-2 8828 (Cycle 9 Supplemental Darks pt3/3)

        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 with no reported problems.

2.0 FLIGHT OPERATIONS SUMMARY:

    2.1 Guide Star Acquisitions:
       Scheduled Acquisitions:  8
Successful:  8

  Scheduled Re-acquisitions:  8
Successful:  8

    2.2 FHST Updates:
Scheduled: 15
Successful: 15

    2.3 Operations Notes:

        GSFC Internal Simulation #8 (EVA-1/Planning/EVA-2) halted execution 
at approximately 6:00 p.m. yesterday.  The three-day exercise will resume 
this morning at 8:00 a.m.

       The EPS recharge ratio upper limit was adjusted at 143/1738Z per an 
operations request.

        Using ROP NS-5, the NSSC-1 engineering report was reset at 144/0319Z.

        The 486 engineering status buffer limits were adjusted at 144/0550Z 
as directed by an operations request.

3.0 SIGNIFICANT FORTHCOMING EVENTS:

        Continuation of normal science observations and calibrations.

/CAW