NASA Hubble Space Telescope Daily Report # 3546
HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science
DAILY REPORT # 3546
PERIOD COVERED: DOY 36
OBSERVATIONS SCHEDULED
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.
ACS/HRC/WFC 10059
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/WFC 9722
Life in the fast lane: The dark-matter distribution in the most massive
galaxy
clusters in the Universe at z>0.5
We propose two-filter ACS observations of a complete sample of 12 very
X-ray
luminous galaxy clusters at 0.5<z<0.7 as a cornerstone of a
comprehensive
multi-wavelength study of the properties of the most massive clusters in
the
universe. Our sample includes the famous systems Cl0016+16 and
MS0451-03; all
other clusters are new discoveries from the MACS survey. Being the
counterparts
of the best-studied systems at lower and higher redshift and comprising
ALL
massive clusters at 0.5<z<0.7 observable from Mauna Kea this sample will
become
the ultimate reference for cluster studies at z>0.5. HST’s unique
capabilities
will allow us to: 1} measure accurately the clusters’ dark matter
distribution
on scales from tens to more than 500/h 50 kpc from observations of
strong and
weak gravitational lensing, 2} use galaxy-galaxy lensing to measure the
shape,
extent, and mass content of the dark-matter halos of both cluster and
field
galaxies, and 3} study the color morphology of mergers and the star
formation
history of galaxies in a high-density environment. The proposed
observations are
complemented by Chandra observations of all our targets {all 12 awarded,
11
executed to date} which provide independent constraints on the dark
matter and
gas distribution in the cluster cores, as well a by extensive
groundbased
observations of weak lensing on yet larger scales, galaxy dynamics, and
the SZ
effect.
ACS/WFC 9744
HST Imaging of Gravitational Lenses
Gravitational lenses offer unique opportunities to study cosmology, dark
matter,
galactic structure, galaxy evolution and quasar host galaxies. They are
also the
only sample of galaxies selected based on their mass rather than their
luminosity or surface brightness. While gravitational lenses can be
discovered
with ground-based optical and radio observations, converting them into
astrophysical tools requires HST. HST has demonstrated that it is the
only
telescope that can in each case precisely locate the lens galaxy,
measure its
luminosity, color and structure, and search for lensed images of the
source
host
galaxy given the typical image separations of ~1”. We will obtain
ACS/WFC
V and
I images and NICMOS H images of 21 new lenses never observed by HST and
NICMOS H
images of 16 lenses never observed by HST in the IR. As in previous
cycles, we
request that the data be made public immediately.
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.
NIC/NIC3 9865
The NICMOS Parallel Observing Program
We propose to continue managing the NICMOS pure parallel program. Based
on our
experience, we are well prepared to make optimal use of the parallel
opportunities. The improved sensitivity and efficiency of our
observations will
substantially increase the number of line-emitting galaxies detected. As
our
previous work has demonstrated, the most frequently detected line is
Halpha at
0.7<z<1.9, which provides an excellent measure of current star formation
rate.
We will also detect star-forming and active galaxies in other redshift
ranges
using other emission lines. The grism observations will produce by far
the best
available Halpha luminosity functions over the crucial–but poorly
observed–redshift range where galaxies appear to have assembled most of
their
stellar mass. This key process of galaxy evolution needs to be studied
with IR
data; we found that observations at shorter wavelengths appear to have
missed a
large fraction of the star-formation in galaxies, due to dust reddening.
We
will
also obtain deep F110W and F160W images, to examine the space densities
and
morphologies of faint red galaxies. In addition to carrying out the
public
parallels, we will make the fully reduced and calibrated images and
spectra
available on-line, with some ground-based data for the deepest parallel
fields
included.
NIC1 9833
T Dwarf Companions: Searching for the Coldest Brown Dwarfs
Faint companions to known stars have historically led to the discovery
of new
classes of stellar and substellar objects. Because these discoveries are
typically limited by the flux ratio of the components in the system, the
intrinsically faintest companions are most effectively identified around
the
intrinsically faintest primaries. We propose to use NICMOS to image a
sample of
22 of the coolest known {T-type} brown dwarfs in the Solar Neighborhood
in
order
to search for fainter and cooler brown dwarf companions. The high
spatial
resolution of the NIC 1 detector enables us to distinguish binary
systems with
apparent separations greater than 0"08, or physical separations greater
than 1.2
AU at the nominal distances of the objects in our sample. Furthermore,
the
substantial sensitivity of NICMOS imaging allows us to probe companion
masses of
5-50 Jupiter masses and companion effective temperatures of 250-1300 K
in a
maximally efficient manner. Based on work to date, we expect that
roughly
20% of
the objects in our sample will be binary, and that one or two of these
will
likely harbor a significantly fainter secondary. Hence, we expect to
find a
companion cooler than any currently known brown dwarf, a potential
prototype for
the next spectral class. In addition, our investigation will add
substantially
to the sample of known binary brown dwarfs, allowing improved
statistical
analyses of the binary fraction, separation distribution, and mass ratio
distribution of these systems, key quantities for probing brown dwarf
formation.
We will also identify optimal substellar systems for astrometric mass
measurements, a critical check for theoretical models of brown dwarfs
and
extrasolar planets.
NIC2 9834
Finding Planets in the Stellar Graveyard: A Faint Companion Search of
White
Dwarfs with NICMOS
We propose to do a deep search for substellar objects in orbit around
white
dwarfs with the newly refurbished NICMOS camera as part of the PI’s
doctoral
thesis work. Direct imaging of planets around main sequence stars is
difficult
due to the large contrast ratio, a problem which is much less severe for
companions to white dwarfs. White dwarfs are not usually considered in
planet
searches but recent theoretical work and observations are motivating new
searches for planetary systems and dust disks around DAZ white dwarfs.
We
propose to conduct the search with the NIC2 coronagraph to find resolved
companions and do photometry to search for unresolved companions through
Near-IR
excesses. We estimate that the survey will be sensitive to brown dwarfs,
high
mass jovian planets, and dust disks. By probing a wide range of orbital
separations and companion masses, this survey will help to answer
questions
about the brown dwarf desert, common envelope evolution, and planet
formation.
HST and NICMOS provide a unique capability to do this search, as no
ground
based
observatory with AO can adequately search for faint companions as close
and
with
such high contrast.
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.
STIS/CCD 10017
CCD Dark Monitor-Part 1
Monitor the darks for the STIS CCD.
STIS/CCD 10019
CCD Bias Monitor – Part 1
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/CCD 10085
STIS Pure Parallel Imaging Program: Cycle 12
This is the default archival pure parallel program for STIS during cycle
12.
STIS/CCD/MA1 9769
STIS Observations of Orbital and Rotational Variations in the Unique
Post-Common
Envelope System HS1136+6646
HS1136+6646 is a recently discovered close-binary system consisting of a
hot
{Teff ~ 120, 000 K} DAO white dwarf and a K7V main sequence companion.
It is
unique in being a relatively bright, nearby example of both a very young
post-common envelope system and a pre-cataclysmic variable system.
Although the
K star component of HS1136+6646 has now been well studied from the
ground, the
white dwarf can only be effectively studied at UV wavelengths from
space. We
propose STIS observations of HS1136+6646 which focus specifically on the
nature
of the white dwarf, i.e., its mass, temperature, age, photospheric
composition
and possible magnetic field. High-dispersion echelle spectra, taken at
quadrature of the 0.83607 day orbital period of the system will provide
an
accurate determination of the gravitational redshift of the white dwarf.
STIS/MA1/MA1 10031
STIS MAMA Cycle 12 Deep Wavecals
This program will obtain deep wavecals for the STIS Echelle modes in
order to
produce improved dispersions solutions. The new wavelength solution is
based on
a physical model of the instrument’s optical elements and will supercede
the
empirical polynomial fit. This work is part of the STIS Calibration
Enhancement
project conducted at the ST-ECF. Deep wavecals are required in order to
take
full advantage of the new line list from the ESA -funded Pt/Cr-Ne
calibration
lamp project and to test the predictive power of physical instrument
model of
STIS. A second epoch of observations will investigate the issue of MSM
repeatability.
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.
WFPC2 10082
POMS Test Proposal: WFII backup parallel archive proposal
This is a POMS test proposal designed to simulate scientific plans
WFPC2 10084
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.
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:
1194-0 Adjust Recharge Ratio Limits for High Sun DOY 2004/036-046 @
036/12:01z
SCHEDULED SUCCESSFUL FAILURE TIMES
FGS GSacq 09 09
FGS REacq 10 10
FHST Update 07 07
LOSS of LOCK
SIGNIFICANT EVENTS: None
