NASA Hubble Space Telescope Daily Report # 3470
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3470
PERIOD COVERED: DOY 289
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/CCD/WFC 9978
The Ultra Deep Field with ACS
The ACS Ultra Deep Field {UDF} is a survey carried out by using Director’s
Discretionary time. The main science driver are galaxy evolution and cosmology.
The primary instrument is the Advanced Camera for Surveys but WFPC2 and NICMOS
will also be used in parallel. The data will be made public. The UDF
consists of
a single ultra-deep field {410 orbits in total} within the CDF-S GOODS
area. The
survey will use four filters: F435W {55 orbits}, F606W {55 orbits}, F775W {150
orbits}, and F850LP {150 orbits}. The F435W {B} and F606W {V} exposures will be
one magnitude deeper than the equivalent HDF filters. The F775W {I} exposure
will be 1.5 magnitude deeper than the equivalent HDF exposure. The depth in
F775W and F850LP is optimized for searching very red objects – like z=6
galaxies
– at the detection limit of the F850LP image. The pointing will be RA{J2000}=3
32 40.0 and Decl.{J2000}=-27 48 00. These coordinates may change slightly
due to
guide star availability and implementation issues. We will attempt to
include in
the field both a spectroscopically confirmed z=5.8 galaxy and a
spectroscopically confirmed type Ia SN at z=1.3. The pointing avoids the gaps
with the lowest effective exposure on the Chandra ACIS image of CDFS. This
basic
structure of the survey represents a consensus recommendation of a Scientific
Advisory Committee to the STScI Director Steven Beckwith. A local Working Group
is looking in detail at the implementation of the survey.
ACS/HRC 9747
An Imaging Survey of the Statistical Frequency of Binaries Among
Exceptionally-Young Dynamical Families in the Main Asteroid Belt
We propose an ambitious SNAPSHOT program to determine the frequency of binaries
among two very young asteroid families in the Main Belt, with potentially
profound implications. These families {of C- and S-type} have recently been
discovered {Nesvorny et al. 2002, Nature 417, 720}, through dynamical modeling,
to have been formed at 5.8 MY and 8.3 MY ago in catastrophic impact events.
This
is the first time such precise and young ages have been assigned to a family.
Main-belt binaries are almost certainly produced by collisions, and we would
expect a young family to have a significantly higher frequency of binaries than
the background, because they may not yet have been destroyed by impact or
longer-term gravitational instabilities. In fact, one of the prime observables
from such an event should be the propensity for satellites. This is the
best way
that new numerical models for binary production by collisions {motivated
largely
by our ground-based discoveries of satellites among larger asteroids}, can be
validated and calibrated. HST is the only facility that can be used to search
for binaries among such faint objects {V>17.5}. We will also measure two
control
clusters, one being an "old" family, and the other a collection of background
asteroids that do not have a family association, and further compare with our
determined value for the frequency of large main-belt binaries {2%}. We request
visits to 180 targets, using ACS/HRC.
ACS/HRC/WFC 10042
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 10044
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/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/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.
ACS/WFPC2 9488
Cosmic Shear – with ACS Pure Parallel Observations
The ACS, with greater sensitivity and sky coverage, will extend our ability to
measure the weak gravitational lensing of galaxy images caused by the large
scale distribution of dark matter. We propose to use the ACS in pure parallel
{non- proprietary} mode, following the guidelines of the ACS Default Pure
Parallel Program. Using the HST Medium Deep Survey WFPC2 database we have
measured cosmic shear at arc-min angular scales. The MDS image parameters, in
particular the galaxy orientations and axis ratios, are such that any residual
corrections due to errors in the PSF or jitter are much smaller than the
measured signal. This situation is in stark contrast with ground-based
observations. We have also developed a statistical analysis procedure to derive
unbiased estimates of cosmic shear from a large number of fields, each of which
has a very small number of galaxies. We have therefore set the stage for
measurements with the ACS at fainter apparent magnitudes and smaller, 10
arc-second scales corresponding to larger cosmological distances. We will adapt
existing MDS WFPC2 maximum likelihood galaxy image analysis algorithms to work
with the ACS. The analysis would also yield an online database similar to that
in archive.stsci.edu/mds/
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/NIC2/NIC3 8792
NICMOS Post-SAA calibration – CR Persistence Part 3
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.
NIC3 9979
The Ultra Deep Field – NICMOS Parallels
This is a plan to manage the NICMOS pure parallels of the ACS Ultra Deep
Survey.
We will obtain a mix of F110W and F160W images along sight-lines within the
mosaiced ACS fields of the CDF-S GOODS and GEMS surveys, with these sight-lines
enabling an examination of the space density and morphologies of the reddest
galaxies.
NIC3 9999
The COSMOS 2-Degree ACS Survey NICMOS Parallels
The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a companion to
program 9822.
STIS 9383
Probing the Grains Responsible for Extinction Using Small Magellanic Cloud
Sightlines
Small Magellanic Cloud sightlines have the greatest potential to relate
specific
interstellar extinction features to distinct grain properties. The reasons for
this are 1} prominent extinction features such as the 2175 Angstrom bump
and the
far-ultraviolet rise vary among SMC targets and 2} grain types may be very
different from those in the Galaxy. Specifically, Welty et al. {2001} recently
identified an SMC sightline that contains dust, but no silicate grains.
Silicates are a dominant source of extinction in all dust models; the SMC
may be
the only location where the importance of silicates can be verified or
disproved. We propose to explore the relationship between grain types and
extinction toward 2 SMC stars with very different extinction curves; AzV 18
lacks a 2175 Angstrom bump and has a strong far-UV rise while the extinction
curve towards the SMC star AzV 456 has a prominent 2175 Angstrom bump and a
much
weaker far-UV rise. We will compare the interstellar abundances of atoms that
are prevalent in silicates {Si, Mg, Fe} toward these 2 stars and use the
results
to constrain dust extinction models. These SMC observations, which can only be
obtained with STIS, are the only direct way to probe the connection between
grain types/environments and extinction. The results from this study will be
useful for modeling and understanding all regions that contain dust {AGN,
circumstellar disks, star formation regions, etc.}.
STIS 9786
The Next Generation Spectral Library
We propose to continue the Cycle 10 snapshot program to produce a Next
Generation Spectral Library of 600 stars for use in modeling the integrated
light of galaxies and clusters. This program is using the low dispersion UV and
optical gratings of STIS. The library will be roughly equally divided among
four
metallicities, very low {[Fe/H] lt -1.5}, low {[Fe/H] -1.5 to -0.5}, near-solar
{[Fe/H] -0.3 to 0.1}, and super-solar {[Fe/H] gt 0.2}, well-sampling the entire
HR-diagram in each bin. Such a library will surpass all extant compilations and
have lasting archival value, well into the Next Generation Space Telescope era.
Because of the universal utility and community-broad nature of this venture, we
waive the entire proprietary period.
STIS/CCD 10000
STIS Pure Parallel Imaging Program: Cycle 12
This is the default archival pure parallel program for STIS during cycle 12.
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 9981
The Ultra Deep Field – STIS parallels
We propose to obtain slitless spectroscopy of objects in the GEMS and GOODS
area
around the UDF.
WFPC2 10069
WFPC2 CYCLE 12 Supplemental Darks, Part 1/3
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 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 9980
The Ultra Deep Field – WFPC2 Parallels
The ACS Ultra Deep Field {UDF} is a survey carried out by using Director’s
Discretionary time. The main science drivers are galaxy evolution and
cosmology.
The primary instrument is the Advanced Camera for Surveys but WFPC2,
NICMOS, and
STIS will also be used in pure parallel mode. The data will be made public. The
UDF consists of a single ultra-deep field {410 orbits in total} within the
CDF-S
GOODS area. We request a modification of the default pure parallel programs.
Rather than duplicate the redder 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,
allowing determination of 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.
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 07 07
FGS REacq 05 05
FHST Update 17 17
LOSS of LOCK
SIGNIFICANT EVENTS:
Start SM Long Duration (9 days) Load testing CCS "D" String.
CCS "F" and "C" String monitor only.
