Status Report

NASA Hubble Space Telescope Daily Report # 3483

By SpaceRef Editor
November 5, 2003
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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

ACS/HRC 10050

ACS Earth Flats

High signal sky flats will be obtained by observing the bright Earth
with the HRC and WFC. These observations will be used to verify the
accuracy of the flats currently used by the pipeline and will provide
a comparison with flats derived via other techniques: L-flats from
stellar observations, sky flats from stacked GO observations, and
internal flats using the calibration lamps. Weekly coronographic
monitoring is required to assess the changing position of the spots.


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 9986

Massive Black Holes in Early Type Galaxies

This program is a continuation of the Cycle 11 ACS/GTO program 9293.
Recently, a nearly perfect relation has been recognized between the
masses of the black holes {for 3×10^6 Msun < M_BH < 3×10^9 Msun} at
the centers of galaxies and the velocity dispersions of their bulges.
However, uncertainties over the exact slope of the correlation still
remain, and it is not known if such a relation extends to black holes
of lower and higher masses. The discovery of small {r ~ a few hundred
pc}, well defined, dust and gas disks in the nuclei of some active
elliptical galaxies opened a new avenue for measuring central mass
distributions. When ionized gas is present, a small number of high
spatial resolution {e.g. STIS} spectra are sufficient to characterize
the disk dynamics and the galaxy’s central mass {e.g., M87, M81, NGC
4374}. We propose to use STIS spectroscopy to measure black hole
masses, using gas dynamics, in the centers of several brightest
cluster galaxies {BCGs}, 2 nearby galaxies with low velocity
dispersions, and a number of elliptical galaxies known to harbor small
nuclear dust disks. The proposed targets encompass a wide range of
black hole masses, allowing us to fully examine the M_BH – sigma
relationship. In Cycle 11, we obtained H-alpha and continuum images of
most of the targets to fully characterize their gaseous and dust
morphologies as well as their core stellar surface profile. In Cycle
12, we complete the imaging and perform STIS spectroscopy of the best

NIC1 9737

A NICMOS direct imaging search for giant planets around the seven
single white dwarfs in the Hyades

We propose to use the NIC1 camera on HST to search for massive giant
planets around the known seven single white dwarfs in the nearby
Hyades cluster at sub-arcsec separations. At an age of 625 Myr, the
white dwarfs had protogenitor masses of about 3 solar masses, and
massive gaseous giant planets should have formed in the massive
circumstellar disks around these ex Herbig A0 stars, probably at
orbital separations similar or slightly larger than that of Jupiter {5
AU} in our own solar system. Such planets would have survived the
post-Main Sequence mass loss of the parent star, and would have
migrated outward adiabatically by a factor 4.5, equal to the ratio of
initial to final stellar mass {3Mo/0.66Mo}, due to conservation of
orbital angular momentum during the mass loss {AGB and PN} phase. Thus
the orbital separation NOW would be 4.5 x 5 AU = 22.5 AU, which at the
distance of the Hyades {45 pc} corresponds to 0.50 arcsec. Simulations
with TinyTim then show that giant planets at this separation with
masses in the range 6-12 Jupiter masses and apparent J and H
magnitudes in the range 20.5-23.3 mag {from Baraffe or Burrows models}
can be spatially resolved around the Hyades white dwarfs. Their J and
H brightnesses are known to be 15 +/- 0.5 mag, implying a median
star-planet brightness ratio of 1000:1 {7.5 mag}. This combination of
dynamic range and orbital separation is observable with NICMOS, by
subtracting images taken at two roll angles. Therefore, the proposed
near-IR diffraction-limited observations in the F110W and F160W
filters promise to resolve giant planets around low-mass stars for the
first time. If successful, the observations would also prove that
giant planets do form around early-type stars more massive than the

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 9735

ACS, NICMOS, and STIS Observations of Three Ongoing Mergers

We propose to make ACS {U, B, V, I, H_alpha}, NICMOS {J, H, K}, and
STIS {long-slit H_alpha} observations of NGC 520, NGC 2623, and NGC
3256, three merging galaxies in the middle of the Toomre Sequence and
currently in the throes of violent relaxation. Two of these {NGC 2623
and NGC 3256} are the most IR luminous galaxies in the sequence.
Hence, these ongoing mergers are ideal candidates for studying the
triggering mechanism responsible for the formation of stars and star
clusters. The ACS observations will allow us to age date the star
clusters, and reliably distinguish clusters from stars based on their
apparent sizes. They will also be used in conjunction with
ground-based measurements of the stellar velocity dispersion to
determine dynamical masses of the clusters and hence address the
question of whether the IMF is truncated. The NICMOS observations will
allow us to penetrate the dust and answer several fundamental
questions such as: What fraction of the young clusters are hidden by
dust? How do these clusters form and evolve? The STIS observations
will allow us to study the kinematics of the young cluster system and
measure the pressure and shock properties which may be triggering the
formation of the clusters. A better understanding of how mergers form
tremendous numbers of clusters and stars in the local universe will
help shed light on processes that were crucial during galaxy assembly
in the high-z universe.


Deep NICMOS Images of the UDF

The ACS Ultra Deep Field {UDF} images will greatly enhance the rich
suite of deep multi-wavelength images in the Chandra Deep Field South
{CDF–S}. We propose to complete the image set with deep near-IR
NICMOS images at 1.1 and 1.6 microns over a significant fraction of
the UDF, providing a critical link between the HST ACS and SIRTF
observations. The timely addition of the near-IR images ensures that
investigators will have images that span the spectrum from X-ray to
far IR. In recognition of the value of the near IR images this
proposal is submitted as a Treasury proposal with no proprietary
period. The proposal team will deliver science quality images,
mosaiced images covering 4.9 sq arc min, and a photometric catalog
complete to an AB mag of 28.2 in both the F110W and F160W filters. The
program also delivers a parallel extremely deep ACS field, 8′ away,
that reaches to within 0.6 mag of the UDF in the same filters as the
UDF. The scientific program of the proposal team focuses on the star
formation history of the universe, evolved galaxies at high redshift,
galaxies at the epoch of reionization, and the redshift evolution of
AGNs and ULIRGs. The HDF-N is currently the only field with
spatially-coincident deep HST imaging in both the optical and near-IR.
The small size of the HDF-N means that large scale structure is the
dominant error in the results from the HDF-N. Providing observations
in a field that is spatially uncorrelated is critically important. The
UDF/CDF-S fulfills that goal. The depth of the UDF ACS imaging, and
the wealth of Great Observatory and ground based observations in the
CDF-S, make these NICMOS observations uniquely valuable. An
extraordinarily rich array of science opportunities await the
community from the NICMOS UDF data.

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 10016

STIS CCD Performance Monitor

This activity measures the baseline performance and commandability of
the CCD subsystem. Only primary amplifier D is used. Bias and Flat
Field exposures are taken in order to measure bias level, read noise,
CTE, and gain. Numerous bias frames are taken to permit construction
of "superbias" frames in which the effects of read noise have been
rendered negligible. Full frame and binned observations are made, with
binning factors of 2 x 1, 1 x 2, 2 x 2, 4 x 1, and 4 x 2. Bias frames
are taken in subarray readouts to check the bias level for ACQ and
ACQ/PEAK observations. All exposures are internals.

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.

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

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 9712

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


Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be

HSTAR 9189: GS Acquisition (2,3,2) @ 309/00:04:26Z ended in FL backup
on FGS 3 due to SSLE on FGS 2 @ 309/00:07:54Z and again @
309/00:09:49Z. GS Re-acquisition (2,3,2) @ 309/01:41:35Z also ended
in FL backup. Under investigation.





Network Testing 1 Mbps Science Ingest Issues scheduled 309/13:00Z –
20:00Z with GDOC, SOC, and HITT using CCS "C" String with CCS Release
4.0.3 and PRD S07200 and CCS "D" String with CCS Release 5.0.3 and PRD
S07200S. The purpose of this testing is to investigate recurring
issues with science data packet drop outs during ingest of 1 Mbps
science data.

SpaceRef staff editor.