Status Report

HST Daily Report #3342

By SpaceRef Editor
April 16, 2003
Filed under , ,

HUBBLE SPACE TELESCOPE

DAILY REPORT     #3342

PERIOD COVERED:  DOY 105

OBSERVATIONS SCHEDULED

 NICMOS/STIS CCD                9405

 The Origin of Gamma-Ray Bursts

 The rapid and accurate localization of gamma-ray bursts {GRBs} promised
by a working HETE-2 during the
 coming year may well revolutionize our ability to study these enigmatic,
highly luminous transients. We
  propose a program of HST and Chandra observations to capitalize on this
extraordinary opportunity. We
 will perform some of the most stringent tests yet of the standard model,
in which GRBs represent
 collimated relativistic outflows from collapsing massive stars. NICMOS
imaging and STIS CCD
 spectroscopy will detect broad atomic features of supernovae underlying
GRB optical transients, at
 luminosities more than three times fainter than SN 1998bw. UV, optical,
and X-ray spectroscopy will be
 used to study the local ISM around the GRB. Chandra spectroscopy will
investigate whether the GRB X-ray
  lines are from metals freshly ripped from the stellar core by the GRB.
HST and CTIO infra-red imaging
 of the GRBs and their hosts will be used to determine whether `dark’
bursts are the product of
 unusually strong local extinction; imaging studies may for the first
time locate the hosts of `short’
 GRBs. Our early polarimetry and late-time broadband imaging will further
test physical models of the
 relativistic blast wave that produces the bright GRB afterglow, and will
provide unique insight into
 the influence of the GRB environment on the afterglow.

 NICMOS                         9484

 The NICMOS Parallel Observing Program

 We propose to manage the default set of pure parallels with NICMOS. Our
experience with both our GO
 NICMOS parallel program and the public parallel NICMOS programs in cycle
7 prepared us to make optimal
 use of the parallel opportunities. The NICMOS G141 grism remains the
most powerful survey tool for
 HAlpha emission-line galaxies at cosmologically interesting redshifts.
It is particularly well suited
 to addressing two key uncertainties regarding the global history of star
formation: the peak rate of
 star formation in the relatively unexplored but critical 1<= z <= 2 epoch, and the amount of star  formation missing from UV continuum-based estimates due to high extinction. Our proposed deep G141  exposures will increase the sample of known HAlpha emission- line objects at z ~ 1.3 by roughly an  order of magnitude. We will also obtain a mix of F110W and F160W images along random sight-lines to  examine the space density and morphologies of the reddest galaxies. The nature of the extremely red  galaxies remains unclear and our program of imaging and grism spectroscopy provides unique information

 
regarding both the incidence of obscured star bursts and the build up of
stellar mass at intermediate
 redshifts. In addition to carrying out the parallel program we will
populate a public database with
 calibrated spectra and images, and provide limited ground- based optical
and near-IR data for the
 deepest parallel fields.

 ACS                            9649

 ACS internal CTE monitor

 The charge transfer efficiency {CTE} of the ACS CCD detectors will
decline as damage due to on-orbit
 radiation exposure accumulates. This degradation will be closely
monitored at regular intervals,
 because it is likely to determine the useful lifetime of the CCDs. All
the data for this program is
 acquired using internal targets {lamps} only, so all of the exposures
should be taken during Earth
 occultation time {but not during SAA passages}. This program emulates
the ACS pre-flight ground
 calibration and post-launch SMOV testing {program 8948}, so that results
from each epoch can be
 directly compared. Extended Pixel Edge Response {EPER} and First Pixel
Response {FPR} data will be
 obtained over a range of signal levels for both the Wide Field Channel
{WFC}, and the High Resolution
 Channel {HRC}.

 ACS                            9673

 CCD Daily Monitor

 This program consists of basic tests to monitor, the read noise, the
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

 WFPC2                          9709

 POMS Test Proposal: WFII parallel archive proposal

 used to take paralell images of random areas of the sky, following the
recommendations of the 2002
 Parallels Working Group.

FLIGHT OPERATIONS SUMMARY:

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

HSTARs:
None

COMPLETED OPS REQs:
None

OPS NOTES EXECUTED:
None

                          SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                     5             5          
FGS REacq                     8             8                
FHST Update                  10            10               
LOSS of LOCK                                                             

SpaceRef staff editor.