HUBBLE SPACE TELESCOPE

DAILY REPORT # 3128

PERIOD COVERED:  0000Z (UTC) 05/31/02 - 0000Z (UTC) 06/02/02

OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

9353

Direct imaging of the progenitors of massive, core-collapse supernovae

Modern supernovae searches in the nearby Universe are discovering vast numbers
of SNe which have massive star progenitors {Types II, Ib and Ic}. The extensive
HST {and ground-based} image archives of galaxies within ~20 Mpc enables their
individual bright stellar content to be resolved. As massive, evolved stars are
the most luminous single objects in a galaxy, the progenitors of core-collapse
SNe should be directly detectable on pre-explosion images. Within the last year
we have set direct mass limits on the progenitors of two SNe Type II-P by
analyzing pre-explosion archive images and follow up HST exposures. We have now
identified six other recent, nearby SNe which have WFPC2 archive exposures of
the site taken before explosion. Additionally, our Cycle 10 SNAP program will
double the WFPC2 image archive of nearby galaxies which significantly increases
the chances of having multi-colour photometry of pre-explosion sites for future
SNe. In this Cycle, we request time on two fronts. Firstly we require 
imaging of
the six SNe with existing pre-explosion data in order to perform exact
astrometry of the SNe positions to around 0.05''. Secondly, as a follow on from
our two successful Cycle 10 programs, we request ToO status for any nearby
core-collapse SN which explodes during Cycle 11 and which has pre-explosion HST
images. The goal of this proposal is to directly identify the progenitor stars
of core-collapse SNe.

ACS 9586

ACS Polarization Calibration

This proposal aims to calibrate the polarization modes most heavily used in
Cycle 11. We need L-flat observations, observations of a polarized star and an
unpolarized star, and an observation of an extended polarized source.

ACS 9476

Galaxy Evolution in the Richest Clusters at z=0.8: the EDisCS Cluster Sample

The study of distant cluster galaxies requires two key ingredients: {1} deep
high-resolution imaging, to constrain galaxy structure; and {2} 8m-class
spectroscopy, to measure stellar content, star-formation rates, dynamics, and
cluster membership. We will reach both conditions with the addition of HST/ACS
imaging to our suite of VLT {36 nights} and NTT {20 nights} observations of 10
confirmed clusters at z~0.8, drawn from the ESO Distant Cluster Survey 
{EDisCS}.
The proposed HST/ACS data will complement our existing optical/IR imaging and
spectroscopy with quantitative measures of cluster galaxy morphologies {i.e.
sizes and shapes, bulge-disk decompositions, asymmetry parameters}, and with
measurements of cluster masses via weak lensing. Major advantages unique to the
EDisCS project include: {i} uniform selection of clusters; {ii} large enough
sample sizes to characterize the substantial cluster-to-cluster variation in
galaxy populations; {iii} large quantities of high quality data from 8m
telescopes; {iv} uniform measurements of morphologies, spectroscopic and
photometric redshifts, SEDs, star-formation/AGN activities, and internal
kinematics; {v} optical selection of clusters to complement the X-ray selection
of almost all high-z clusters in the ACS GTO programs; {vi} forefront numerical
simulations designed specifically to allow physical interpretation of observed
differences between the high-z and local clusters.

ACS 9024

SBC flat field uniformity

The stability and uniformity of the low-frequency flat fields {L-flat} of all
ACS detectors will be assessed by using multiple pointing observations of the
globular cluster NGC6681 - thus imaging moderately dense stellar fields. By
placing the same star over different portions of the detectors and measuring
relative changes in its brightness it will be possible to determine local
variations in the response of the detectors. Based on previous experience with
STIS, it is deemed that a total of nine different pointings will suffice to
provide adequate characterization of the flat field stability in any given 
band.
For each filter to be tested, the baseline consists of 9 pointings with 
steps of
~20% of the FOV in a diagonal cross pattern. During SMOV, the complement of
filters to be tested is limited to the following: for the SBC, F125LP and
F150LP. In order to provide complementary data for the geometric distortion
programmes {9027 and 9028}, and also to check that the distortion is not
chromatic, three additional exposures will be taken with F125LP with a very
small {~10 pixel} offset from the centre {see proposals 9027 and 9028}.
Execution of this programme must await completion of programme 9011 {ACS to FGS
alignment} and the ensuing PDB update.

ACS/CAL 9558

ACS weekly Test

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.

ACS/SBC 9022

SBC Dark Current Measurement

This proposal acquires dark count images for the ACS/SBC. As the dark rate is
expected to be a strong function of detector temperature, the sequence is
designed to fill an entire block of non-SAA orbits. Over that time, the 
detector
temperature is expected to rise with time since turn on.

ACS/WFC 9584

ACS Default {Archival} Pure Parallel Program II.

The Advanced Camera for Surveys (WFC) was used to test ACS pure parallels.

ACS/WFC 9575

Default {Archival} Pure Parallel Program.

The Advanced Camera for Surveys (WFC) was used to test ACS pure parallels in
POMS.

ACS/WFC/HRC 8947

Weekly Test.

The Advanced Camera for Surveys (WFC and HRC) was used to perform basic 
tests to
monitor, the read noise, the development of hot pixels and test for any source
of noise in ACS CCD detectors. This program will be executed at least once 
a day
for the entire lifetime of ACS.

HST 9382

A Large Targeted Survey for z < 1.6 Damped Lyman Alpha Lines in SDSS QSO
MgII-FeII Systems.

We have searched the first public release of SDSS QSO spectra for low-z 
{z<1.65}
metal absorption lines and found over 200 large rest equivalent width MgII-FeII
systems. Previously, we empirically showed that such systems are good 
tracers of
large neutral gas columns, with ~50% being classical damped Lyman alpha {DLA}
systems {N_HI>=2*10^20 cm^-2}. Here we propose to follow up a well-defined
subset of 79 of them to search for DLAs with 0.47<z<1.60. Only QSOs brighter
than g'=19 were selected. The QSO emission and DLA absorption redshifts were
constrained to virtually eliminate data loss due to intervening Lyman limit
absorption. Consequently, we expect to discover ~40 new DLAs, which is a
three-fold increase in this redshift interval. This will significantly improve
our earlier low-z DLA statistical results on their incidence, cosmological mass
density, and N_HI distribution. The results will also allow us to better
quantify the empirical DLA -- metal-line correlation. With this improved
understanding, the need for follow-up UV spectroscopy will lessen and, with the
release of the final database of SDSS QSO spectra {an ~25-fold increase}, the
number of low-z DLAs could be increased arbitrarily. Thus, the power of the
large and statistically-sound SDSS database in combination with a proven
technique for finding low-z DLAs will, over the next few years, essentially
solve the problem of making an accurate determination of the cosmic 
evolution of
the neutral gas component down to z~0.4.

NICMOS 9557

NICMOS flats: Camera 3 narrow filters and grisms

This proposal obtains sequences of NICMOS Camera 3 to build high S/N flat 
fields
for all the narrow filters and grisms.

NICMOS 9269

NICMOS Parallel Thermal Background

NICMOS Camera 3 pure parallel exposures in the F222M filter will be 
obtained for
the entire duration of SMOV to establish the stability of the 
HST+NCS+Instrument
thermal emission.

NICMOS 8986

NICMOS Photometry Test

This proposal contains the necessary exposures to re-calibrate NICMOS.

NICMOS 8790

NICMOS Post-SAA calibration - CR Persistence Part 1.

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.

STIS 9271

Coronal Dynamics and the Complete Flare Energy Budget for the M Dwarf AD Leo

We will carry out six orbits {two visits of 4 and 2 orbits duartaion} of STIS
E140M TIME-TAG mode spectroscopy of the active red dwarf star AD Leo,
coordinated with Chandra-HETGS {50 ksec} observations, to accurately 
measure for
the first time the complete energy budget of stellar coronal flares. FUV
observations of the Fe XXI 1354 A coronal forbidden lines are needed from STIS
to determine the dynamical energy losses of the flares. Chandra HETGS spectra
will be used to measure the temporal changes in the coronal emission measure,
temperature, density, and elemental abundances. AD Leo is one of the brightest
dMe stars in the ultraviolet and X-ray regions and flaring rate data suggests
that we should see about 10 moderate {factor of a few} and one large {factor of
10-20 enhancement} flares in a 30 hour observation. Ground-based optical and
radio monitoring will also be attempted.

STIS/CCD 8904

Bias Monitor-Part 2.

The Space Telescope Imaging Spectrograph (CCD) was used to monitor the bias in
the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4 in order
to build up high-S/N superbiases and track the evolution of hot columns.

STIS/CCD 9066

Closing in on the Hydrogen Reionization Edge of the Universe.

The Space Telescope Imaging Spectrograph (CCD) was used in parallel constrain
the Hydrogen reionization edge in emission that marks the transition from a
neutral to a fully ionized IGM at a predicted redshifts.

STIS/CCD 8902

Dark Monitor-Part 2.

The Space Telescope Imaging Spectrograph (CCD) was used to monitor the darks.

STIS/CCD 9317

Pure Parallel Imaging Program: Cycle 10.

The Space Telescope Imaging Spectrograph (CCD) was used to perform the default
archival pure parallel program for STIS during cycle 10.

STIS/CCD 9077

Survey of the LMC Planetary Nebulae.

The Space Telescope Imaging Spectrograph (CCD) was used to perform a snapshot
survey of all known LMC planetary nebulae {PNe} in order to study the
co-evolution of the nebulae and their central stars, and to probe the chemical
enrichment history of the LMC.

STIS/CCD/MA1 9067

UV Detectability of Bright Quasars in the Sloan Fields.

The Space Telescope Imaging Spectrograph (CCD and MA1) was used to take MAMA
spectra of approximately 30 new, bright, high-redshift quasars in each of the
next three cycles.

WF/PC-2 9043

Cepheid Distances to Early-type Galaxies.

The WF/PC-2 was used to continue observations in the HST Key Project on the
Extragalactic Distance Scale and the HST project on the "Calibration of Nearby
Type Ia Supernovae'' that have greatly improved our knowledge of the Hubble
Constant by providing a solid zero point for the Tully- Fisher {TF} 
relation and
Type Ia Supernovae {SNIa}. However, severe inconsistencies remain for distance
estimators to early-type galaxies such as surface brightness fluctuations 
{SBF},
the planetary nebula luminosity function {PNLF}, the fundamental plane 
{FP}, and
the globular cluster luminosity function {GCLF}. As a result, the distance to
the Virgo cluster core remains uncertain by as much as 20 determination is
directly affected by a lingering 0.1 mag {5 uncertainty in the photometric
calibration of the WFPC2. Resolving these issues is essential not only to firm
up the extragalactic distance scale, but also to understand the mass and
velocity structure of the local universe. SBF in particular is emerging as the
method of choice for mapping local velocity fields to 10, 000 kms because it
offers an order of magnitude less Malmquist bias than TF, and SNIa are too rare
to study large scale flows effectively. This project will tighten the
photometric calibration of the WFPC2, and provide a solid Cepheid calibration
for SBF and PNLF.

WF/PC-2 9180

Gamma-ray Burst Progenitors: Probing Their Environment.

The WF/PC-2 was used to perform a target of opportunity observation of 
gamma ray
burster (GRB), GRB-011121. GRB astronomy is a field maturing at a phenomenal
rate. Three important new observational and theoretical discoveries, formulated
over the last twelve months, allow the proposer to address new, and in many
cases, more sophisticated questions than could have been posed previously. 
These
developments: the discovery of X-ray lines in GRB 991216; the observation that
N_H as deduced from X-ray afterglow are one to two orders of magnitude larger
than the dust extinction inferred from optical afterglow; and the growing
realization that the afterglow emission may exhibit features of dust echoes,
appear to offer unexpected and new diagnostics that will directly inform us
about the progenitor, the circum-progenitor material and the immediate
interstellar environs.

WF/PC-2 9319

POMS Test Proposal: WFII Backup Parallel Archive Proposal II.

The WF/PC-2 was used to execute a POMS test proposal, designed to simulate
future scientific plans.

WF/PC-2 9318

POMS Test Proposal: WFII Parallel Archive Proposal Continuation.

The WF/PC-2 was used to perform the generic target version of the WFPC2 
Archival
Pure Parallel program. The program was used to take parallel images of random
areas of the sky, following the recommendations of the Parallels Working 
Group.

WFPC2 8938

WFPC2 CYCLE 9 SUPPLEMENTAL DARKS pt3/3.

This dark calibration program obtains 3 dark frames every day to provide data
for monitoring and characterizing the evolution of hot pixels.

FLIGHT OPERATIONS SUMMARY:

HSTARs:
8668  REacq (1,3,1) failed to RGA Mode Only. @ 151/08:46:08z
8669  Command Display @ 151/11:07z
8670  C string DataClient @ 151/18:13z
8671  CCS-C, B, & G strings lost data @ 151/21:13z

COMPLETED OPS REQs:
16779-0  SI CCL Quick Updates @ 151/2227z

OPS NOTES EXECUTED:
1011-0  FSW File Transfer to Cmd Que


                        SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                16             16
FGS REacq                27             27
FHST Update              41             41
LOSS of LOCK            None


Operations Notes:
None


SIGNIFICANT EVENTS:

Continuation of Servicing Mission Orbital Verification and the gradual 
resumption
of normal science observations and calibrations.