NASA Hubble Space Telescope Daily Report # 3375
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3375
PERIOD COVERED: DOY 153
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.
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.
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 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.
STIS 9499
Brown Dwarf Binaries as Tests of Substellar Evolution
We propose to obtain STIS spectroscopy of two brown dwarf binaries for
which
dynamical masses are being obtained by monitoring the orbital motion
using
ground-based telescopes with adaptive optics. The HST/STIS spectra will
allow to
study the LiI resonance line at 670.8 nm. The lithium depletion of the
members
of these binaries will be estimated with the aid of synthetic spectra.
These
observations will be compared to model predictions of lithium depletion
as a
function of age and mass, and hence will provide an observational test to
the
theory of substellar objects. Spin-offs will be the measurement of the
strength
of Halpha emission, an indicator of chromospheric activity in cool
atmospheres,
and comparing the shape of the optical continuum with model spectra with
different dust opacities.
WFPC2 9592
WFPC2 CYCLE 11 Standard Darks
This dark calibration program obtains dark frames every week in order to
provide
data for the ongoing calibration of the CCD dark current rate, and to
monitor
and characterize the evolution of hot pixels. Over an extended period
these
data
will also provide a monitor of radiation damage to the CCDs.
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.
WFPC2 9596
WFPC2 CYCLE 11 INTERNAL MONITOR
This calibration proposal is the Cycle 11 routine internal monitor for
WFPC2, to
be run weekly to monitor the health of the cameras. A variety of internal
exposures are obtained in order to provide a monitor of the integrity of
the CCD
camera electronics in both bays {gain 7 and gain 15}, a test for quantum
efficiency in the CCDs, and a monitor for possible buildup of
contaminants on
the CCD windows.
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 9615
Cycle 11 MAMA Dark Monitor
This test performs the routine monitoring of the MAMA detector dark
noise. This
proposal will provide the primary means of checking on health of the MAMA
detectors systems through frequent monitoring of the background count
rate. The
purpose is to look for evidence of change in dark indicative of detector
problem
developing.
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.
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.
ACS/HRC/WFC 9728
Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae
Type Ia supernovae {SNe Ia} provide the only direct evidence for an
accelerating
universe, an extraordinary result that needs the most rigorous test. The
case
for cosmic acceleration rests on the observation that SNe Ia at z = 0.5
are
about 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 SNe Ia
result
attributed to grey dust or cosmic evolution of the SN Ia peak luminosity
would
not show this change of sign. We have obtained a toehold on this putative
“epoch of deceleration” with SN 1997ff at z = 1.7, and 3 more at z > 1
from
our Cycle 11 program, all found and followed by HST. However, this is too
important a test to rest on just a few objects, anyone of which could be
subject
to a lensed line-of-sight or misidentification. Here we propose to extend
our
measurement with observations of twelve SNe Ia in the range 1.0 < z < 1.5
or 6
such SNe Ia and 1 ultradistant SN Ia at z = 2, that will be discovered as
a
byproduct from proposed Treasury and DD programs. These objects will
provide a
much firmer foundation for a conclusion that touches on important
questions of
fundamental physics.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.) None
COMPLETED OPS REQs:
16984-0 HST486 Memory Dump for Verification of SMAC201/HMAC09 @
153/14:05z
OPS NOTES EXECUTED: NONE
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 08 08
FGS REacq 07 07
FHST Update 19 19
LOSS of LOCK
SIGNIFICANT EVENTS:
In preparation for Battery 6 Capacity Test, dumped 486 memory to verify
SMAC 201 Version I and
HMAC09 are properly loaded in 486 memory (OR 16984). Battery 6 Capacity
Test, 1st opportunity
154/11:52Z.
Successfully completed checkout of two VEST SIMSS units. Testing was run
from SMOR with
CCS "B" String and the latest Ops database in the test account. Verified
ingest of telemetry
formats (HN, PN, and TN) at 32 kbps, AN and fixed D format at 4 kbps, and
fixed E format.
Uplinked, dumped, and compared HST486 hardware and FSW loads, executed
NSSC-1 Status Buffer
dump, and played back SSR, including science and engineering data.
PASS Release 31.76 was successfully placed into formal operations 6/2/03
on
the SOGS cluster
and aliveness testing of the new software was successfully completed.
The
look-alike areas
of STOSC for operational images will be shifted to reflect this
installation by the end of
the week.
