Daily 3419

HUBBLE SPACE TELESCOPE

DAILY REPORT******* # 3419

PERIOD COVERED: DOY 216

OBSERVATIONS SCHEDULED

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 {z1.65} 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 0.47z1.60. 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.

WFPC2 9458

Probing the Formation & Evolution of M31's Outer Disk and Halo

The fossil record of galaxy formation and evolution is imprinted on
the spatial distribution, ages and metallicities of galactic stellar
populations. The observations proposed here build significantly upon
our extensive ground-based and archival WFPC2 programs and aim to
constrain the formation and evolution of our nearest large neighbor,
M31. We propose deep imaging of 8 fields in the outer disk and halo,
several of which have been identified from our panoramic ground-based
CCD survey {covering ~ 26 square degrees} to possess significant
stellar density and/or potential metallicity variations. Deep
colour-magnitude diagrams reaching ~2-3 magnitudes below the
horizontal branch will be constructed, allowing detailed
characterization of the luminous evolved stellar populations via the
red giant metallicity distribution, the luminous asymptotic giant
branch, the horizontal branch morphology and the red clump, as well as
the detection of a main-sequence that may be present from any younger
component. Our primary goals are to: {i} quantify the stellar
population variations associated with M31 halo substructure, including
the newly- discovered giant stellar stream, and {ii} derive stringent
constraints on the age and metallicity of stars in the far outer disk.
These observations will directly address two key predictions of cold
dark matter hierarchical galaxy formation models.

ACS 9470

Deep Lyman alpha images of starburst galaxies

We propose a pilot study to obtain deep ACS Ly-alpha images of a
carefully selected sample of local starburst galaxies. Ly-alpha
imaging of such objects has become feasible with ACS. These
observations will bring unprecedented insight into the processes
regulating the luminosity of the cosmologically important Ly-alpha
line. Our targets cover the full range of observed Ly-alpha
properties. They have been chosen to investigate the effects of dust,
the starburst luminosity, and outflows within the ISM. The sample is
optimized for a most favorable trade-off between the relevant
parameter space and the minimum number of orbits. We can build on this
pilot study for a much larger follow-up survey in a later cycle. Deep
H Alpha and H Beta high-resolution images from the ground will allow
us to quantify the Ly-alpha emission {or its lack} and its attenuation
as a function of the local dust content. The H Alpha emission at a
given location will constrain the intrinsic intensity of the expected
Ly-alpha emission. A non-detection will allow us to quantify the
fraction of Ly- alpha photons destroyed within the neutral gas, and to
correlate this fraction with the properties of the neutral gas and
dust. Since Ly-alpha emitters are used to identify and study galaxies
at redshift 3-6, our study will document the circumstances when a
star--forming galaxy shows Ly-alpha emission. This will be an
important first step towards an empirical calibration of the relation
between Ly-alpha and the star--formation rate.

WFPC2 9589

WFPC2 Decontaminations and Associated Observations Pt. 1/3

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 9595

WFPC2 CYCLE 11 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.

STIS 9606

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS 9608

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 9612

STIS CCD Hot Pixel Annealing Cycle 11

The effectiveness of the CCD hot pixel annealing process is assessed
by measuring the dark current behavior before and after annealing and
by searching for any window contamination effects. In addition CTE
performance is examined by looking for traps in a low signal level
flat. Follows on from proposal 8906.

ACS 9675

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.

STIS 9708

STIS Pure Parallel Imaging Program: Cycle 11

This is the default archival pure parallel program for STIS during
cycle 11.

WFPC2 9709

POMS Test Proposal: WFII parallel archive proposal

This is the 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 2002 Parallels
Working Group.

WFPC2 9710

POMS Test Proposal: WFII backup parallel archive proposal

This is a POMS test proposal designed to simulate scientific plans.

ACS/WFC 9842

A Snapshot Search for Halo Very-Low-Mass Binaries

We propose a snapshot search for binary M subdwarf stars. These nearby
stars have high velocities and low metallicies that identify them as
members of the old Galactic halo {Population II}. ACS imaging is
requested to search for secondary companions. This supplements a
previous snapshot program that only obtained 10 observations. The
observed binary fraction will be compared to the disk M dwarf fraction
to look for differences in star formation. It is likely that a system
suitable for orbital mass determinations will be found. In this case,
future HST observations could determine the first masses for
very-low-mass, low-metallicity stars.

ACS/HRC 9976

The Parallaxes and Proper Motions of Two Nearby Neutron Stars

We propose to measure the parallax of two nearby neutron stars to the
highest possible level of accuracy, ~.0.5 mas. The primary goal is to
determine the neutron-star radius at infinity with better than 1 km
precision, and therewith obtain a direct constraint on the equation of
state of matter at supra-nuclear density. The required flux and
temperature determinations are easiest for the so-called isolated or
radio-quiet neutron stars because of their apparently completely
thermal spectrum. We argue that the importance of the possible results
warrants a study to the best possible level of the best possible
sources, and request 24 orbits for the two brightest isolated neutron
stars, RX J1856.5-3754 and RX J0720.4-3125. We will also determine
whether the enigmatic RX J0720.4-3125 is an old magnetar or an
accreting source, based on its luminosity and proper motion.

ACS 9984

Cosmic Shear With ACS Pure Parallels

Small distortions in the shapes of background galaxies by foreground
mass provide a powerful method of directly measuring the amount and
distribution of dark matter. Several groups have recently detected
this weak lensing by large-scale structure, also called cosmic shear.
The high resolution and sensitivity of HST/ACS provide a unique
opportunity to measure cosmic shear accurately on small scales. Using
260 parallel orbits in Sloan textiti {F775W} we will measure for the
first time: beginlistosetlength sep0cm setlengthemsep0cm setlength
opsep0cm em the cosmic shear variance on scales 0.7 arcmin, em the
skewness of the shear distribution, and em the magnification effect.
endlist Our measurements will determine the amplitude of the mass
power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20,
and the mass density Omega_m with s/n=4. They will be done at small
angular scales where non-linear effects dominate the power spectrum,
providing a test of the gravitational instability paradigm for
structure formation. Measurements on these scales are not possible
from the ground, because of the systematic effects induced by PSF
smearing from seeing. Having many independent lines of sight reduces
the uncertainty due to cosmic variance, making parallel observations
ideal.

FLIGHT OPERATIONS SUMMARY:

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

COMPLETED OPS REQs: None

OPS NOTES EXECUTED:
0911-0* Limit Management During WFPC2 Decontamination (M001) @ 217/0112z

*************************** SCHEDULED**** SUCCESSFUL*** FAILURE TIMES
FGS GSacq*************** 04*********************** 04
FGS REacq*************** 11*********************** 11
FHST Update************* 09************************ 09
LOSS of LOCK


SIGNIFICANT EVENTS:

Intercept load being process for SMS216, the intercept time is 218/0329z.

Completed Long Duration System Loading and Command Communication
Controller testing Day 213 - 216 using CCS "C" and "D" Strings.* Test
was successful, however, each test encountered Network and/or System
errors.* During the CCC checkout, a Network problem developed at
approximately 213/13:51Z.* System load test had clients loaded on Core
= 100, Backbone = 479, and HSTnet = 354 which ran the duration of the
weekend.