Status Report

NASA Hubble Space Telescope Daily Report # 3488

By SpaceRef Editor
November 13, 2003
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HUBBLE SPACE TELESCOPE

DAILY REPORT # 3488

PERIOD COVERED: DOY 315

OBSERVATIONS SCHEDULED

ACS 9468

ACS Grism Parallel Survey of Emission- line Galaxies at Redshift z pl 7

We propose an ACS grism parallel survey to search for emission-line
galaxies toward 50 random lines of sight over the redshift interval 0
< z pl 7. We request ACS parallel observations of duration more than one orbit at high galactic latitude to identify ~ 300 HAlpha emission-line galaxies at 0.2 pl z pl 0.5, ~ 720 O IILambda3727 emission-line galaxies at 0.3 pl z pl 1.68, and pg 1000 Ly-alpha emission-line galaxies at 3 pl z pl 7 with total emission line flux f pg 2* 10^-17 ergs s^-1 cm^-2 over 578 arcmin^2. We will obtain direct images with the F814W and F606W filters and dispersed images with the WFC/G800L grism at each position. The direct images will serve to provide a zeroth order model both for wavelength calibration of the extracted 1D spectra and for determining extraction apertures of the corresponding dispersed images. The primary scientific objectives are as follows: {1} We will establish a uniform sample of HAlpha and O II emission-line galaxies at z<1.7 in order to obtain accurate measurements of co-moving star formation rate density versus redshift over this redshift range. {2} We will study the spatial and statistical distribution of star formation rate intensity in individual galaxies using the spatially resolved emission-line morphology in the grism images. And {3} we will study high-redshift universe using Ly-alpha emitting galaxies identified at z pl 7 in the survey. The data will be available to the community immediately as they are obtained.

ACS 9760

ACS Imaging of the Gemini Deep Deep Survey Fields: Galaxy Assembly at
z = 1.5

We are presently carrying out the deepest redshift survey ever
undertaken {the Gemini Deep Deep Survey}. Spectra of extraordinary
quality have been taken in order to obtain redshifts in the so-called
“redshift desert” at 1

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 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/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 0.50.5. 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 9892

H-alpha Snapshots of Nearby Galaxies observed in F300W: Quantifying
Star Formation in a Dusty Universe

Previous studies of nearby galaxies show large discrepancies between
different star formation {SF} indicators on large {>100 pc, or even
global} scales: the strikingly complex interplay of young stars, dust
and ionized gas are the primary cause of this variance. The few
galaxies in the HST Archive with both WFPC2 H-alpha and mid-UV {F255W
or F300W} imaging show this complex geometry extending down to <10 pc scales. We propose a SNAPshot survey in the ACS/WFC H-alpha filter of 48 galaxies of all Hubble types, that are nearby but beyond the Local Group, and that were previously imaged with WFPC2 in the mid-UV and in F814W. We aim to provide a benchmark for understanding the SF processes in both normal and star-bursting galaxies, at spatial resolutions unattainable from the ground for a large and varied galaxy sample. These data can be applied to a wide range of astrophysical problems and will, therefore, be made public immediately. Our science goals are to: {1} spatially resolve the dust clouds and filaments which strongly affect mid-UV and H-alpha derived SF rates, {2} test how the large-scale correlation between H-alpha and mid-UV flux breaks down on pc scales, and {3} model the propagation of star formation by comparing the SF over time scales of ~100 Myr {via mid-UV} and ~5 Myr {via H-alpha}. This will {4} significantly improve our insight into, and calibration of SF in UV-bright galaxies at high z, and into the cosmic SF history.

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

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.

NIC2 9726

A NICMOS search for obscured supernovae in starburst galaxies

Recent near-IR monitoring campaigns were successful in detecting
obscured supernovae {SNe} in starburst galaxies. The inferred SN rate
is much higher than that obtained in previous optical campaigns, but
it is still significantly lower than expected by the high level star
formation of these systems. One possible explanation for the shortage
of SNe is that most of them occur in the nuclear region, where the
limited angular resolution of groundbased observations prevents their
detection. We propose NICMOS SNAP observations of a sample of
starburst galaxies already observed once by NICMOS, with the goal of
exploiting its sensitivity and angular resolution to detect nuclear
obscured SNe which might have been missed by groundbased surveys.
These observation will allow to assess the real SN rate in starbust
galaxies and deliver a sample of SN occurring in the extreme
environment of galactic nuclei. We expect to detect more than 55 SNe
{if the whole sample is observed}. If the number of SNe detected in
the program is much lower than expected it would prompt for a revision
of our understanding of the relation between the star formation rate
and the SN rate.

NIC2 9856

A near-IR imaging survey of submm galaxies with spectroscopic redshifts

Submillimeter {submm} surveys with SCUBA have identified a population
of obscured star-forming and active galaxies at high redshift. Our
recent spectroscopic campaigns with the Keck-10m telescope have
uncovered redshifts for 37 SCUBA galaxies. The wide redshift range of
the radio identified submm population {z=1-4} implies that many
varieties of sources driven by different physical processes may be
selected in a submm survey. Only HST observervations have the
resolution to detect any changes in the morphologies of SCUBA galaxies
with increasing cosmic time. We propose to use HST-NICMOS, ACS to
obtain 2-filter images of a sample of 15 SCUBA galaxies with redshifts
spanning z=0.8-3.5. Our goal is to understand what physical process
{major mergers?} drive their strong evolution and great luminosities,
and what the implications are for galaxy evolution models.

STIS 9441

Zinc Abundances in Damped Ly-Alpha Systems at z < 0.5: A Missing Link in the Chemical History of Galaxies

The evolution of metallicity in damped Lyman alpha {DLA} quasar
absorption systems is an important constraint on the global star
formation history of the universe, but remains a big puzzle at
present. The H I column density weighted mean metallicity in DLAs is
expected to rise to solar values at low redshifts, based on cosmic
chemical evolution models, because the mass-weighted mean metallicity
of local galaxies is near- solar. However, current DLA abundance
studies are highly uncertain and cannot distinguish between evolution
and no evolution in the mean metallicity at redshifts 0.4 < z < 3.5. The existing data are particularly incomplete because no Zn measurements exist for z < 0.4, and only 2 exist for z < 0.5, which spans the past 35-45 % of the age of the universe. To pin down the cosmic age-metallicity relation all the way to the present epoch, we propose to measure Zn abundances in five DLAs at 0.1 < z < 0.5. We propose to use HST STIS because it is the only existing instrument that can measure the necessary UV lines. Our observations will clearly distinguish between no metallicity evolution vs. the predicted evolution. Our data will also provide Cr measurements, which will help to estimate the dust abundance. The proposed observations are crucial for tying together the absorption and emission histories of gas and stars in galaxies and for clarifying the relation of DLAs to present-day galaxies.

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.

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 10075

WFPC2 CYCLE 12 Intflat and Viflat Sweeps and Filter Rotation Anomaly
Monitor

Using intflat observations, this WFPC2 proposal is designed to monitor
the pixel-to-pixel flatfield response and provide a linearity check.
The intflat sequences, to be done once during the year, are similar to
those from the Cycle 11 program 9597. The images will provide a backup
database in the event of complete failure of the visflat lamp as well
as allow monitoring of the gain ratios. The sweep is a complete set of
internal flats, cycling through both shutter blades and both gains.
The linearity test consists of a series of intflats in F555W, in each
gain and each shutter. As in Cycle 11, we plan to continue to take
extra visflat, intflat, and earthflat exposures to test the
repeatability of filter wheel motions.

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

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               7                         7
FGS REacq               9                         9
FHST Update             14                       14
LOSS of LOCK

SIGNIFICANT EVENTS:

CCS “B” and “C” Strings will be configured in Test mode through
12/15/03 to accommodate SE access to UNIX products and to allow VMS
and UNIX PNMs to be received on the Test side (not on the Ops side) at
any time during this period.

HST Project Interface testing to verify DSN desktops scheduled
316/13:00Z – 18:00Z with HST STOCC, JPL, GDOC, DSS 46, NISN, and SOC
using CCS “B” String in Test Mode with CCS Release 4.0.3 and PRD
O06300T.

SpaceRef staff editor.