Status Report

NASA Hubble Space Telescope Daily Report # 3521

By SpaceRef Editor
January 1, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Have A Happy & Healthy New Year!!!





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
– 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
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 9748

Ceres: High-Resolution Mapping and Determination of Physical Properties

We propose a modest, 6-orbit HST ACS/HRC program to fully map the asteroid 1
Ceres for the first time. These high signal-to-noise, high resolution maps will
be obtained in three ACS filter bandpasses from the visible to the UV. The
of our program are to advance knowledge about Ceres dramatically, to resolve
certain longstanding issues regarding Ceres, and to support planning for the
Dawn Discovery mission’s planned orbital tour of Ceres. The specific scientific
objectives of this proposed Cycle 12 effort are: {1} To achieve dense
phase coverage with multi-spectral imaging over the complete rotation period of
Ceres to map its surface; {2} To resolve surface features and investigate the
nature of the Piazzi feature detected by HST/FOC in 1995; {3} To track surface
features in order to unambigously determine Ceres’ pole position; {4} To
the three-dimensional shape of Ceres better than any existing shape model in
order to significantly refine density measurements; and {5} To map Ceres’ color
variegation and photometric parameters in order to identify possible surface
units for the first time. These goals require high resolution visible and
ultraviolet imaging, which can only be obtained with HST. As we demonstrate in
this proposal, the January, 2004 opposition of Ceres is the best in the next 6
years for both data quality and planning of the Dawn mission.


CCD Daily Monitor

This program consists of basic tests to monitor, the read noise, the
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 9772

Galaxy Populations at Very Large Cluster Radii: The Outskirts of MS1054-03 at

We propose to use the Advanced Camera for Surveys to image four selected fields
in the outskirts of the rich, X-ray luminous cluster MS1054-03 at z=0.83. The
high-resolution and sensitivity of ACS is required in order to study the
properties of the population of galaxies falling into the cluster for the first
time. By targeting regions of the cluster well beyond the virial radius, we
will: {1} study the transformation of infalling field spirals into cluster
early-types using, e.g., the morphology-density relation to large radii and
low local densities; {2} determine the star-formation histories of those field
galaxies most recently accreted by the cluster, using accurate colors,
morphologies, bulge-to- disk ratios, bulge and disk scale lengths, M/L ratios
and line strengths; and {3} measure the frequency of galaxy-galaxy mergers and
interactions in the infall region. By combining wide-field HST/ACS data with
wide-field multi-object spectroscopy from the Magellan and Keck telescopes, we
can test the predictions made by galaxy formation models, study how field
spirals become early-type cluster members, and better constrain the formation
and evolution of galaxies in both clusters and the field.


The local Hubble flow and the density field within 6 Mpc

Great progress has been made recently in accurate distance measurements of
nearby galaxies beyond the Local Group based on the luminosity of the tip
of the
red giant branch {TRGB}. Over the last three years, snapshot surveys with HST
have provided us with the TRGB distances for more than a hundred nearby
obtained with an accuracy of about 10%. The local velocity field within 5 Mpc
exhibits a significant anisotropy which disagrees with a spherical
flow. The local Hubble flow is very cold, with 1-D rms deviations of ~30 km/s.
Cosmological simulations with Cold Dark Matter can only realize such low
dispersions with a combination of a low mean density of matter and a
component with negative pressure. There may be a constraint on the equation of
state w=-p/rho. Our observations will concentrate on 116 galaxies whose
distances lie within 4 – 6 Mpc, allowing us to trace a Dark Matter distribution
in the Local Volume with twice the information currently available. The program
is a good one for SNAP mode because the order and rate that the
observations are
made are not very important, as long as there is good completion over several


Accurate and Robust Calibration of the Extragalactic Distance Scale with the
Maser Galaxy NGC4258

The extragalactic distance scale {EDS} is defined by a comparison of Cepheid
Period-Luminosity {PL} relations for nearby galaxies and the LMC, whose
uncertain distance is thereby the SOLE anchor. Studies of maser sources
the central black hole in the galaxy NGC4258 have provided the most accurate
extragalactic distance ever {7.2+/- 0.5Mpc}. Since this distance is well
determined and based on GEOMETRIC arguments, NGC4258 can provide a much needed
new anchor for the EDS. We propose multi-epoch BVIH observations of NGC4258 in
order to discover about 100 Cepheids and to characterize their light curves
2-3 times greater accuracy than was previously possible with WFPC2. At 90
{48 in Cycle 12; 42 in Cycle 13}, this is a relatively large program. However,
the result will have a major impact on the EDS, and substantial attention must
be paid to characterization and minimization of systematic errors, as from
metallicity, crowding, and blending. The resulting dataset will be the most
complete for Cepheids in any galaxy yet studied with HST. In an ongoing
NASA-funded program {OSS-SARA}, we are using new analysis techniques and radio
data to reduce uncertainty in the geometric distance to < 3% {0.07 mag}. With
this improved geometric distance and the BVIH data, we will be able to
the zero point of the PL relation ROBUSTLY to <4% {0.09 mag}.

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
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

NIC3 10014

Spectrophotometry of FAINT IR STANDARDS

Faint spectrophotometric standard stars required for COS and the SBC channel on
ACS have been established via the STIS FASTEX program that has executed
over the
last three cycles. Cycle 12 is an especially opportune time to establish
companion faint IR standards for WFC3, because the NICMOS proposal 9998
observations in cycle 12 of all 6 of the primary standard stars in order to
establish the absolute flux calibration of the three grism modes to 1%. In
addition to WFC3, these new faint secondary IR standards will be a significant
step towards establishing flux standards for JWST, as well as for SNAP, SIRTF,
and SOFIA. The 6 primary standards included in Propid=9998 are in the range of
V=11-13 and include three hot pure hydrogen WDs and 3 solar analogs. We propose
to establish new IR faint standards in the 15-17 mag range. Appropriate
types for faint IR standards are solar analogs and hotter WDs. Many M type and
cooler stars are variable, so that long term monitoring is required before
committing HST time to such cool stars. A few G type and WD faint stars will
provide a set of faint IR standards with minimal sky and color coverage.
Existing HST images of any candidates can provide verification that there
are no
contaminating stars above the 1% level within 2-3arcsec. However, the ACS
calibration field in 47 Tuc is too crowded for linking to ground based
observations. If the other candidates are selected from SDSS or other ground
based data, then the NICMOS and STIS acquisition images can provide this
verification, as well as correction factors for arbitrary photometric size
apertures. The SNAP team is providing the northern faint stars using unreleased
SDSS data. In addition, the extreme coolest types such as L and T stars have
proven essential to sorting out the long wavelength QE of ACS; both the ACS and
eventually WFC3 calibrations could be improved with knowledge of L and T
SEDs in
the region beyond 0.95 microns. In addition to the primary purpose of ACS
QE vs.
wavelength and broad band F814W and F850LP calibrations, these three stars in
C.} below are at the flux level required for WFC3 grism calibration. The
brighter M, L, and T standard stars will each require a NICMOS orbit, while
faint standard requires two Nicmos orbits and one STIS orbit for complete
wavelength coverage. The STIS spectra of the M and L stars are done as ACS
calibrations in cycles 12 and 11, respectively. An additional faint WD has
already been proposed for 2 Nicmos and 4 STIS orbits in their cycle 12 programs
already. See Table 1 for a summary of the 18 orbit allocation for this program
10014. Bright stars in the V=0-6 mag range would be useful for direct
comparisons to NIST calibrated lamps. This comparison would offer the
opportunity to compare two fundamentally different realms of physics: pure
hydrogen stellar models and laboratory black body physics. Unfortunately, the
Nicmos bright limit is V=~8 for a solar analog and a 1s exposure without
defocussing the OTA. The primary Sloan standard BD+17d4708 at V=9.9 is safely
fainter than this Nicmos limit.

NIC3 9979

The Ultra Deep Field – NICMOS Parallels

This is a plan to manage the NICMOS pure parallels of the ACS Ultra Deep
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


NICMOS Post-SAA calibration – CR Persistence Part 1.

A new procedure proposed to alleviate the CR-persistence problem of NICMOS.
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
darks will be non-standard reference files available to users with a USEAFTER
date/time mark.

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
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 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

STIS/CCD 10085

STIS Pure Parallel Imaging Program: Cycle 12

This is the default archival pure parallel program for STIS during cycle 12.


The Ultra Deep Field – STIS parallels

We propose to obtain slitless spectroscopy of objects in the GEMS and GOODS
around the UDF.

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

WFPC2 10067

WFPC2 Cycle 12 Decontaminations and Associated Observations

This proposal is for the monthly WFPC2 decons. Also included are instrument
monitors tied to decons: photometric stability check, focus monitor, pre- and
post-decon internals {bias, intflats, kspots, & darks}, UV throughput check,
VISFLAT sweep, and internal UV flat check.

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 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
The primary instrument is the Advanced Camera for Surveys but WFPC2,
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
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


Significant Spacecraft Anomalies: (The following are preliminary reports of
potential non-nominal performance that will be investigated.) None



                             SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS GSacq                 12                        12
FGS REacq                 5                          5
FHST Update               26                        26


SpaceRef staff editor.