Daily 3586

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3586

PERIOD COVERED: DOY 97

OBSERVATIONS SCHEDULED

ACS/HRC/WFC 10060

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.

ACS/HRC/WFC 9884

Dwarf Elliptical Galaxies in Nearby Groups: Stellar Populations and
Abundances

The M81 group is of the nearest galaxy groups, but its properties are
quite different from the Local Group, providing a different
evolutionary environment for its member galaxies. This team has been
studying M81-group analogs to Local Group dwarf elliptical {dE}
galaxies. We observed two M81-group dEs with WFPC2: the results were
published in Caldwell et al. {1998}. These observations revealed the
upper two magnitudes of the red giant branch, yielding distance via
the luminosity of the red giant branch tip, mean abundance via the
mean giant branch color and first assessment of the star formation
history via the frequency of occurrence of upper-AGB stars. Despite
the different environment, the two M81-group dEs follow the Local
Group {absolute magnitude, mean abundance} relation. But without data
for additional dEs in nearby groups, particularly at higher
luminosities, we can't definitely say whether this relation is
universal or not. Establishing the answer to this question is vital
because the relation is fundamental to theories of dE formation within
dark matter halos, and the general applicability of these theories
requires demonstration that the relation isn't strongly influenced by
environment. This proposal requests ACS/WFC observations of five
M81-group dEs to resolve this question.

ACS/WFC 9717

Low Redshift Cluster Gravitational Lensing Survey

This proposal has two main scientific goals: to determine the dark
matter distribution of massive galaxy clusters, and to observe the
high redshift universe using these clusters as powerful cosmic
telescopes. Deep, g, r, i, z imaging of a sample of low-z {0.2-0.4}
clusters will yield a large sample of lensed background galaxies with
reliable photometric redshifts. By combining strong and weak lensing
constraints with the photometric redshift information it will be
possible to precisely measure the cluster dark matter distribution
with an unprecedented combination of high spatial resolution and area
coverage, avoiding many of the uncertainties which plague ground-based
studies and yielding definitive answers about the structure of massive
dark matter haloes. In addition, the cosmological parameters can be
constrained in a largely model independent way using the multiply
lensed objects due to the dependence of the Einsteinng radius on the
distance to the source. We can also expect to detect several highly
magnified dropout galaxies behind the clusters in the redshift ranges
4-5 5-6 and 7-8, corresponding to a drop in the flux in the g, r, and
i bands relative to longer wavelength. We will obtain the best
information to date on the giant arcs already known in these clusters,
making possible detailed, pixel-by-pixel studies of their star
formation rate, dust distribution and structural components, including
spiral arms, out to a redshift of around z~2.5 in several passbands.

ACS/WFC/HRC 9771

The local Hubble flow and the density field within 6 Mpc

Great progress has been made recently in accurate distance
measurements of nearby galaxies beyond the Local Group based on the
luminosity of the tip of the red giant branch {TRGB}. Over the last
three years, snapshot surveys with HST have provided us with the TRGB
distances for more than a hundred nearby galaxies obtained with an
accuracy of about 10%. The local velocity field within 5 Mpc exhibits
a significant anisotropy which disagrees with a spherical
Virgo-centric flow. The local Hubble flow is very cold, with 1-D rms
deviations of ~30 km/s. Cosmological simulations with Cold Dark Matter
can only realize such low dispersions with a combination of a low mean
density of matter and a substantial component with negative pressure.
There may be a constraint on the equation of state w=-p/rho. Our
observations will concentrate on 116 galaxies whose expected distances
lie within 4 - 6 Mpc, allowing us to trace a Dark Matter distribution
in the Local Volume with twice the information currently available.
The program is a good one for SNAP mode because the order and rate
that the observations are made are not very important, as long as
there is good completion over several years.

ACS/WFC/WFPC2 9822

The COSMOS 2-Degree ACS Survey

We will undertake a 2 square degree imaging survey {Cosmic Evolution
Survey -- COSMOS} with ACS in the I {F814W} band of the VIMOS
equatorial field. This wide field survey is essential to understand
the interplay between Large Scale Structure {LSS} evolution and the
formation of galaxies, dark matter and AGNs and is the one region of
parameter space completely unexplored at present by HST. The
equatorial field was selected for its accessibility to all
ground-based telescopes and low IR background and because it will
eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS
instrument. The imaging will detect over 2 million objects with I 27
mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and
extremely red galaxies out to z ~ 5. COSMOS is the only HST project
specifically designed to probe the formation and evolution of
structures ranging from galaxies up to Coma-size clusters in the epoch
of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The
size of the largest structures necessitate the 2 degree field. Our
team is committed to the assembly of several public ancillary datasets
including the optical spectra, deep XMM and VLA imaging, ground-based
optical/IR imaging, UV imaging from GALEX and IR data from SIRTF.
Combining the full-spectrum multiwavelength imaging and spectroscopic
coverage with ACS sub-kpc resolution, COSMOS will be Hubble's ultimate
legacy for understanding the evolution of both the visible and dark
universe.

STIS/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS/CCD 10020

CCD Bias Monitor - Part 2

Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1,
and 1x1 at gain = 4, to build up high-S/N superbiases and track the
evolution of hot columns.

STIS/CCD/MA1 9874

Probing IGM Phases, Metals, and the Cosmic Web with New SDSS QSOs

We propose STIS G140L SNAPSHOT observations of 100 new z 1 QSOs from
the Sloan Digital Sky Survey for studies of the IGM. These targets
will be chosen to simultaneously maximize IGM pathlength and to form
closely spaced groups of 2-8 QSO sightlines within 1 h^-1 Mpc of a
foreground galaxy. These observations will, in the long term, provide
a rich database of target QSOs for detailed study by COS of the IGM
phases, metallicity, and relationship to the large scale structure. In
the near term, these observations will detect up to 10 Lyman alpha
clouds with N_HI 10^14 and 3 clouds with N_HI 10^15, per target.
Thus they will provide an immediate test of filamentary structure in
the "cosmic web" within 1 h^-1 Mpc of galaxies. We ask for 22 minute
exposures for each target with STIS/G140L to obtain S/N = 5-16 for
these V = 16 - 18 QSOs. These observations will be sensitive to Lyman
alpha equivalent widths ranging from 300 mA for the brighter sources
to 600 mA at the fainter end. These targets represent a Deltaz
pathlength of 17 {at 50% yield}, with Deltaz = 10 in the range where
Lya, Lyb, and O VI lie in the HST band. These observations will also
refine predictions of the FUV flux of QSOs based on the larger SDSS
sample and will estimate the degree to which such factors as intrinsic
and Galactic extinction, variability, and intervening absorption can
be controlled. If successful, this technique could make
UV-prequalification SNAPs of QSOs obsolete, at a significant savings
of HST time. Our observations lie at the median duration for SNAPs,
and in the range most likely to be executed. Our program accomplishes
both near- and long-term goals at a relatively low investment of time,
and thus is ideally suited for a SNAP proposal. To ensure maximum
scientific return for our own purposes and for additional science
{HVCs, Galactic halo} we waive the right to a proprietary data period.

WFPC2 10067

WFPC2 Cycle 12 Decontaminations and Associated Observations

This proposal is for the monthly WFPC2 decons. Also included are
instrument monitors tied to decons: photometric stability check, focus
monitor, pre- and post-decon internals {bias, intflats, kspots, &
darks}, UV throughput check, VISFLAT sweep, and internal UV flat
check.

WFPC2 10070

WFPC2 CYCLE 12 Supplemental Darks Part 2/3

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:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None

COMPLETED OPS REQs:
17119-0 TDRS 171 Test Event @ 097/16:41z
17120-0 ACS and STIS EEPROM memory dumps @ 097/21:59z

OPS NOTES EXECUTED: NONE

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 08 08
FGS REacq 04 04
FHST Update 18 18
LOSS of LOCK

SIGNIFICANT EVENTS:

Continue NICMOS Proposal 10097, adjust NCS setpoint temperature by
-0.5 K @ 098/11:58Z via SMS.

Set-up and Execution of HST FSW 2.5b On-orbit Functional, Ops
Acceptance Test scheduled 098/10:00Z - 099/04:00Z with GDOC, HITT, SE,
and VEST using CCS "D" String (prime) with CCS Release 5.0.3.1 and PRD
O06400ST and CCS "C" String (secondary) with CCS Release 4.0.3.1 and
PRD O06400T. The purpose of this testing is to verify the new
functionality of FSW 2.5b with PRD O6400 in an operational scenario.