Hubble Space Telescope Daily Report # 3363

HUBBLE SPACE TELESCOPE

DAILY REPORT # 3363

PERIOD COVERED: DOY 134

OBSERVATIONS SCHEDULED

NICMOS 8791

NICMOS Post-SAA calibration – CR Persistence Part 2

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. The keyword ‘USEAFTER=date/time’ will also be added to
the
header of each POST-SAA DARK frame. The keyword must be populated with
the
time,
in addition to the date, because HST crosses the SAA ~8 times per day so
each
POST-SAA DARK will need to have the appropriate time specified, for users
to
identify the ones they need. Both the raw and processed images will be
archived
as POST-SAA DARKSs. Generally we expect that all NICMOS
science/calibration
observations started within 50 minutes of leaving an SAA will need such
maps to
remove the CR persistence from the science images. Each observation will
need
its own CRMAP, as different SAA passages leave different imprints on the
NICMOS
detectors.

ACS 9352

The Deceleration Test from Treasury Type Ia Supernovae at Redshifts 1.2
to 1.6

Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating
universe, an extraordinary result that needs a rigorous test. The case
for
cosmic acceleration rests on the observation that SNe Ia at z ~ 0.5 are ~
0.25
mag fainter than they would be in a universe without acceleration. A
powerful
and straightforward way to assess the reliability of the SN Ia
measurement and
the conceptual framework of its interpretation is to look for cosmic
deceleration at z >= 1. This would be a clear signature of a mixed
dark-matter
and dark-energy universe. Systematic errors in the SN Ia result
attributed to
grey dust or cosmic evolution of the SN Ia peak luminosity would not show
this
change of sign. We have demonstrated proof of this concept with a single
SN Ia,
SN 1997ff at z = 1.7, found and followed by HST. The results suggest an
early
epoch of deceleration, but this is too important a conclusion to rest on
just
one object. Here we propose to use HST for observations of six SNe Ia in
the
range 1.2 <= z <= 1.6, that will be discovered as a byproduct from
proposed
Treasury programs for high-latitude ACS surveys. Six objects will provide
a
much
firmer foundation for a conclusion that touches on important questions of
fundamental physics.

NICMOS 9386

Infrared Photometry of a Statistically Significant Sample of KBOs

While the discovery rate of Kuiper Belt objects is accelerating, the
physical
study of this new region of the solar system has been slowed by a lack of
basic
astrophysical data. Photometric observations of the majority of the more
than
400 known KBOs and Centaurs are rudimentary and incomplete, particularly
in the
infrared. The multicolor optical-infrared photometry that exists for a
small
subset of KBOs often shows significant discrepancies between observations
by
different observers. Their intrinsic faintness puts them at the practical
limits
of ground-based systems. In July 2001 we began what will be the largest
uniform
sample of optical photometry of KBOs with a WFPC2 SNAPSHOT program that
will
perform accurate photometry at V, R, and I on a sample of up to 150
targets. We
seek to greatly enhance the value of this survey by obtaining J and H
photometry
on the same sample using NICMOS. Combined optical and infrared broad band
photometry is a far more powerful tool for physical studies than is
either
alone. Our sample includes objects that will be observed at thermal
infrared
wavelengths by SIRTF and will be used with those data to derive the first
accurate diameters, albedos, and surface properties for a large sample of
KBOs.

STIS 9441

Zinc Abundances in Damped Ly-Alpha Systems at z < 0.5: A Missing Link in
the
Chemical History of Galaxies

The evolution of metallicity in damped Lyman alpha {DLA} quasar
absorption
systems is an important constraint on the global star formation history
of the
universe, but remains a big puzzle at present. The H I column density
weighted
mean metallicity in DLAs is expected to rise to solar values at low
redshifts,
based on cosmic chemical evolution models, because the mass-weighted mean
metallicity of local galaxies is near- solar. However, current DLA
abundance
studies are highly uncertain and cannot distinguish between evolution and
no
evolution in the mean metallicity at redshifts 0.4 < z < 3.5. The
existing data
are particularly incomplete because no Zn measurements exist for z < 0.4,
and
only 2 exist for z < 0.5, which spans the past 35-45 % of the age of the
universe. To pin down the cosmic age-metallicity relation all the way to
the
present epoch, we propose to measure Zn abundances in five DLAs at 0.1 <
z <
0.5. We propose to use HST STIS because it is the only existing
instrument that
can measure the necessary UV lines. Our observations will clearly
distinguish
between no metallicity evolution vs. the predicted evolution. Our data
will
also
provide Cr measurements, which will help to estimate the dust abundance.
The
proposed observations are crucial for tying together the absorption and
emission
histories of gas and stars in galaxies and for clarifying the relation of
DLAs
to present-day galaxies.

ACS 9472

A Snapshot Survey for Gravitational Lenses among z >= 4.0 Quasars

Over the last few years, the Sloan Digital Sky Survey has revolutionized
the
study of high-redshift quasars by discovering over 200 objects with
redshift
greater than 4.0, more than doubling the number known in this redshift
interval.
The sample includes eight of the ten highest redshift quasars known. We
propose
a snapshot imaging survey of a well-defined sample of 250 z > 4.0 quasars
in
order to find objects which are gravitationally lensed. Lensing models
including
magnification bias predict that at least 4% of quasars in a flux-limited
sample
at z > 4 will be multiply lensed. Therefore this survey should find of
order 10
lensed quasars at high redshift; only one gravitationally lensed quasar
is
currently known at z > 4. This survey will provide by far the best sample
to
date of high-redshift gravitational lenses. The observed fraction of
lenses can
put strong constraints on cosmological models, in particular on the
cosmological
constant Lambda. In addition, magnification bias can significantly bias
estimates of the luminosity function of quasars and the evolution
thereof; this
work will constrain how important an effect this is, and thereby give us
a
better understanding of the evolution of quasars and black holes at early
epochs, as well as constrain models for black hole formation.

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 9480

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.

ACS/WFPC2 9481

Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS
Survey
Fields

In anticipation of the allocation of ACS high-latitude imaging survey{s},
we
request a modification of the default pure parallel program for those
WFPC2
parallels that fall within the ACS survey field. Rather than duplicate
the red
bands which will be done much better with ACS, we propose to observe in
the
near-ultraviolet F300W filter. These data will enable study of the
rest-frame
ultraviolet morphology of galaxies at 0<z<1. We will determine the
morphological
k-correction, and the location of star formation within galaxies, using a
sample
that is likely to be nearly complete with multi-wavelength photometry and
spectroscopic redshifts. The results can be used to interpret
observations of
higher redshift galaxies by ACS.

ACS 9482

ACS Pure Parallel Lyman-Alpha Emission Survey {APPLES}

Ly-alpha line emission is an efficient tool for identifying young
galaxies at
high redshift, because it is strong in galaxies with young stars and
little or
no dust — properties expected in galaxies undergoing their first burst
of
star- formation. Slitless spectroscopy with the ACS Wide-Field Camera and
G800L
grism allows an unmatched search efficiency for such objects over the
uninterrupted range 4 <~ z <~ 7. We propose the ACS Pure Parallel
Ly-alpha
Emission Survey {“APPLES”}, to exploit this unique HST capability and
so
obtain the largest and most uniform sample of high redshift Ly-alpha
emitters
yet. Parallel observations will allow this survey to be conducted with
minimal
impact on HST resources, and we will place reduced images and extracted
spectra
in the public domain within three months of observation. We aim to find ~
1000
Ly-alpha emitters, 5 times the biggest current sample of Ly-alpha
emitters.
This
unprecedented sample will provide robust statistics on the populations
and
evolution of Ly-alpha emitters between redshifts 4–7; a robust
measurement of
the reionization redshift completely independent of the Gunn-Peterson
trough;
spatial clustering information for Ly-alpha emitters which would let us
probe
their bias function and hence halo mass as a function of redshift; many
galaxies
at redshift exceeding 6; and lower redshift serendipitous discoveries.

STIS 9507

STIS/UV snapshot survey of bright AGN

We propose a UV spectroscopic snapshot survey of bright AGN, quadrupling
the
number of Seyferts UV spectra and adding dozens of new quasars, aimed at
the
following goals: beginenumerate em Finding the relationship between the
intrinsic luminosity of the AGN and the maximum velocity {and width} of
the
outflow emanating from it, and determining the frequency of outflows in
low-z
AGN as a function of luminosity. em Surveying IGM absorption line systems
in
numerous new sight-lines. em Identifying promising targets for
observations
with
the future highly sensitive Cosmic Origin Spectrograph. endenumerate A
35-minute
snapshot with exposures in either the G140L or G230L will yield spectra
with a
minimum S/N > 15 per resolution element at all wavelengths for all our
potential
targets. This will allow us to be sensitive to absorption lines to a
limiting
equivalent width of 0.3 Angstrom at the 3 Sigma level. In order to
facilitate
rapid observational follow up, we waive the data proprietary period
entirely.

WFPC2 9594

WFPC2 CYCLE 11 SUPPLEMENTAL DARKS pt2/3

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 1×1, 1×2, 2×1, and 2×2 bin settings at gain=1,
and 1×1
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 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 9655

ACS Post-SMOV UV Contamination Monitor

A standard star field {NGC6681} is observed about once a month through
all the
ACS broad band UV filters. NGC6681 hosts several UV spectro – photometric
standard stars for which accurate spectra have been {and will continue to
be}
measured with STIS. The target cannot be observed for three months from
mid
November through to mid February, so the standard star GRW+70 will be
observed
twice in its stead. This programme continues the UV sensitivity
monitoring
campaign {ACS SMOV proposal 9010} of the HRC and SBC after the end of the
SMOV
period. An SBC dark current measurement is taken as the last exposure of
each
SBC sequence.

ACS 9674

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.

NICMOS 9702

NICMOS Parallel Thermal Background

NICMOS Camera 2 pure parallel exposures in the F222M and F237M filters to
establish the stability of the HST+NCS+Instrument thermal emission. This
data
will be compared against the already available Camera 3 measurements in
F222M
which show an increased thermal background.

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.

STIS/CCD/MA1 9982

Intergalactic-Ionized Helium toward HS 1700+6416 at maximum QSO
brightness

We propose to measure the UV energy distribution of HS 1700+6416 {z=2.73}
in the
range 1200-3000 A. Scientific background is that HS 1700 has been
observed
recently by FUSE in a long integration {390 ksec}. Due to an unexpected
brightening of the QSO by a factor of 3 to 4 compared to earlier FUSE and
HUT
observations the new observations yielded a HeII forest spectrum of
spectacular
quality. The aim of the proposed HST observation is to measure the UV
energy
distribution of HS 1700 the knowledge of which is essential for an
optimal
evaluation of the FUSE HeII spectrum.

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: None

††††††††††††††††††††††† SCHEDULED†††† SUCCESSFUL††† FAILURE TIMES
FGS
GSacq†††††††††††† 9†††††††††††††††††††††††† 9
† †††††
FGS REacq†††††††††††† 7†††††††††††††††††††††††† 7
FHST Update†††††††††† 19†††††††††††††††††††††† 19
LOSS of LOCK

SIGNIFICANT EVENTS: None