Status Report

NASA Hubble Space Telescope Daily Report # 3750

By SpaceRef Editor
December 7, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT        # 3750

PERIOD COVERED: DOY 341

OBSERVATIONS SCHEDULED

ACS/HRC 10375

Stability of the ACS CCD: Flat fielding, Photometry, Geometry

This program will verify that the low frequency flat fielding, the
photometry, and the geometric distortion are stable in time and across
the field of view of the CCD detectors. A moderately crowded stellar
field, located ~6′ West of the center of the cluster 47 Tuc, is
observed every three months with the WFC and HRC using the full suite
of broad and narrow band filters. The same field has been observed
during SMOV to derive low frequency corrections to the ground flats
and to create a master catalogue of positions and magnitudes from
dithered observations of the cluster. In Cycles 11-12, this field was
observed again using single pointings at various roll angles. The
positions and magnitudes of objects are used to monitor local and
large scale variations in the plate scale and the sensitivity of the
detectors. The Cycle 13 program will continue to monitor these effects
and will derive an independent measure of the detector CTE.

ACS/HRC 10401

A Proper Motion Search for Intermediate Mass Black Holes in Globular
Clusters

Establishing the presence or absence of intermediate-mass black holes
{IMBH} in globular clusters is crucial for understanding the evolution
of dense stellar systems. We propose a systematic search for IMBHs by
conducting an imaging/proper motion study of the centers of five of
the closest, most centrally concentrated Galactic globular clusters.
ACS/HRC observations allow for accurate proper motion measurements for
stars all the way into the center of each cluster. Our approach
consists of exploiting the blue/near-ultraviolet wavelength range in
each of cycles 13 and 14, in order to dim both the bright red giants
and the background of faint red stars, hence alleviating the crowding
problems experienced by previous studies. Both filter and target
selection are critical for the success of this project, and no
previous HST program has an appropriate combination to allow proper
motion measurements for most stars into the very centers of crowded
clusters. The velocity measurements will allow us to: {i} place
constraints on the mass of a central black hole in each cluster
{detailed calculations show that the proposed observations are
sufficient to detect any central black hole with a mass as low as 3000
solar masses at the greater than 3 sigma level}; {ii} derive the
internal velocity dispersion as a function of cluster radius; {iii}
verify or reject previous reports of cluster rotation; and {iv}
directly measure any velocity anisotropy as a function of radius.

ACS    /    HRC/NIC1/WFC 10190

The Star Formation History and Metallicity Evolution of M33: A
Comprehensive Study of Disk Evolution

We will obtain deep, panchromatic imaging photometry of stellar
populations in four fields ranging from 0.5 to 4 scale lengths across
the disk of the Local Group spiral M33. The observations are designed
to detect the oldest main-sequence turnoffs in three outer disk
fields, and to reach the crowding limit in the innermost field. We
will combine the photometry data with information we already have
in-hand on abundances from stars and H II regions in M33 to derive the
star formation history and metallicity evolution of the M33 disk. The
information from our four fields will allow us to obtain {1} the ages
of the oldest disk stars and the radial variation of their ages; {2}
the radial variation of the star formation history and its nature
{e.g., constant, declining, or bursting}; and {3} the metallicity
distribution in each field and the time evolution of the metallicity
gradient. Our team, an experienced mix of photometrists,
spectroscopists, and galaxy evolution theorists, will use the results
from this program to construct a comprehensive chemo- dynamical model
for the M33 disk. This detailed study of M33 will be a key in
developing an understanding of the formation and evolution of disks
that can be applied to studies of disks at both low and high redshift,
and will also yield a wealth of information on stellar populations,
chemical evolution, and star clusters that will be of great value to
future investigators.

ACS/HRC/WFC 10367

ACS CCDs daily monitor- cycle 13 – part 1

This program consists of a set of basic tests to monitor, the read
noise, the development of hot pixels and test for any source of noise
in ACS CCD detectors. The files, biases and dark will be used to
create reference files for science calibration. This programme will be
for the entire lifetime of ACS.

ACS/WFC 10188

In-Depth Study of The Antennae with NICMOS and ACS

We propose new observations of “The Antennae” {NGC 4038/39}, the
nearest and youngest example of a major disk-disk merger, with NICMOS
and ACS. The long overdue NICMOS observations will allow us to
penetrate the dust in the Overlap Region, measure the P_alpha emission
and CO band strengths of young clusters, and study supernova remnants
in heavily obscured regions using [FeII] images. The high resolution
{0.05″ pixel} ACS observations will allow us for the first time to
reliably distinguish clusters from stars based on their apparent
sizes, and to potentially identify hundreds of supernova remnants that
may control the energy balance and feedback mechanisms within the ISM
{based on [SII] images}. In conjunction with our previous WFPC2, GHRS,
and STIS observations, the new data will provide answers to
fundamental questions such as: How do these clusters form and evolve?
How quickly are they destroyed and what fraction of the field stars
were formed in clusters. How many clusters are hidden by dust? How do
the clusters and associated supernovae affect the local and global
ISM? What are the dynamical masses of the clusters, and are the
stellar IMF’s truncated? Simultaneous parallel observations will also
determine whether clusters can form in the more quiescent environment
of the inner tails. A better understanding of how mergers form
tremendous numbers of clusters and stars in the local universe will
help shed light on processes that are crucial during galaxy assembly
throughout the observable universe.

ACS/WFC/WFPC2 10092

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.

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration – CR Persistence Part 5

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 10337

The COSMOS 2-Degree ACS Survey NICMOS Parallels

The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a
companion to program 10092.

S/C 10358

Guide Star Test for program 10265

Guide Star Test for program 10265.

ACS/HRC 9973

Intensive Coverage of the Eta Carinae Event in 2003

For a variety of reasons, HST can provide a very special and unique
data set when Eta Car experiences its next spectroscopic event in
mid-2003. Explaining the phenomenon is only part of the motivation.
This star and its ejecta have unique characteristics that make them
important for several branches of astrophysics; and when a
spectroscopic event occurs, it’s like varying the parameters in an
experiment {or rather, set of experiments}. The 2003 event may be the
only chance in the forseeable future to obtain such a data set,
especially with HST. Eta Carinae has extreme parameters; it is
mysterious in surprisingly basic ways; and HST/ACS/HRC can gather
useful data on it at a terrific rate. As we explain below, the
proposed data set will be valuable in several independent ways: It
will help solve a specific set of current problems, it will constitute
a large and unique archival data base for both stellar and nebular
astrophysics, and it will be well-suited for educational uses.

WFPC2 10363

WFPC2 CYCLE 13 Intflat and Visflat 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 12 program 10075. 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 12, we plan to
continue to take extra visflat, intflat, and earthflat exposures to
test the repeatability of filter wheel motions.

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                09                       09 
FGS Reacq                08                       08 
FHST Update              11                       11 
LOSS of LOCK 

SIGNIFICANT EVENTS: None

SpaceRef staff editor.