Status Report

NASA Hubble Space Telescope Daily Report # 3597

By SpaceRef Editor
April 24, 2004
Filed under , ,
NASA Hubble Space Telescope Daily Report # 3597

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science





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 9766

The Globular Cluster Systems of Spiral Galaxies along the Hubble Sequence

While the globular cluster {GC} systems of ellipticals and ongoing
mergers have been relatively well-studied with HST, very little is
known about the GC systems of spirals besides the Milky Way and M31.
To constrain GC/galaxy formation models, especially where spirals are
the merger progenitors of ellipticals, it is crucial to understand
their GC properties. We propose to obtain ACS images of three edge-on
spirals, spanning the Hubble sequence, with Keck spectroscopic
follow-up. This will effectively double the number of well-studied
spiral systems. We will detect 100-200 GCs per galaxy, sufficient to
reveal GC subpopulations, their relative numbers, radial trends, and
dependences on Hubble type {e.g., a bulge vs. disk origin for red
GCs}. For half of our GCs we will be able to measure individual sizes.
By providing a much-needed comparative benchmark, these data will
allow researchers to better exploit the large existing HST database of
GCs in E/S0 galaxies.

ACS/WFC 9811

Establishing the Metallicity Distribution in Normal Giant Ellipticals

NGC 3377 and 3379, the Leo Group ellipticals at d=11 Mpc, are the
nearest E galaxies commonly regarded to be structurally" normal", and
as such, they are keystone objects for understanding the evolution and
early star formation history of large ellipticals. The ACS/WFC camera
now gives us the ability to obtain the metallicity distribution
function {MDF} of their stellar population by direct resolution and
photometry of their halo stars. To do this, we will follow the same
highly successful techniques we have previously used for NGC 5128 with
WFPC2 {V, I} imaging: the {V-I} colors of the brightest red-giant
stars are highly sensitive to metallicity, and their locations in the
color-magnitude diagram can be used for direct construction of the
MDF. This will be a major step forward to understanding the formation
history of these cosmologically dominant galaxies.

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.

STIS/CCD 10018

CCD Dark Monitor-Part 2

Monitor the darks for the STIS CCD.

STIS/CCD 10020

CCD Bias Monitor – Part 2

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 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


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

HSTAR 9393: GS Acquisition (2,0,2) @ 114/03:47:16Z failed. There
were no flags indicating a GS Acquisition failure, except an ESB
message a0a which is DETECT_FL_TIMEOUT (FGS Fine Lock failed – Timed
out waiting for fine lock FGS: 2). FHST Map @ 114/04:31:25Z had
errors of -15.686, 8.898, and -10.734. Under investigation.


1224-2 Bay 5 WEB Temp Limit Change @113/1053z
1225-0 – SMA Training (Open)

                          SCHEDULED     SUCCESSFUL    FAILURE TIMES
GSacq               9                         8              114/0347z 
FGS REacq               7                         7
FHST Update             21                       21


SpaceRef staff editor.