Status Report

NASA Hubble Space Telescope Daily Report # 3738

By SpaceRef Editor
November 18, 2004
Filed under , ,

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT # 3738

PERIOD COVERED: DOY 321

OBSERVATIONS SCHEDULED

ACS/WFC 10325

Low Redshift Cluster Gravitational Lensing Survey

This proposal has two main scientific goals: to determine the dark
matter distribution of massive galaxy clusters, and to observe the
high redshift universe using these clusters as powerful cosmic
telescopes. Deep, g, r, i, z imaging of a sample of low-z {0.2-0.4}
clusters will yield a large sample of lensed background galaxies with
reliable photometric redshifts. By combining strong and weak lensing
constraints with the photometric redshift information it will be
possible to precisely measure the cluster dark matter distribution
with an unprecedented combination of high spatial resolution and area
coverage, avoiding many of the uncertainties which plague ground-based
studies and yielding definitive answers about the structure of massive
dark matter haloes. In addition, the cosmological parameters can be
constrained in a largely model independent way using the multiply
lensed objects due to the dependence of the Einsteining radius on the
distance to the source. We can also expect to detect several highly
magnified dropout galaxies behind the clusters in the redshift ranges
4-5 5-6 and 7-8, corresponding to a drop in the flux in the g, r, and
i bands relative to longer wavelength. We will obtain the best
information to date on the giant arcs already known in these clusters,
making possible detailed, pixel-by-pixel studies of their star
formation rate, dust distribution and structural components, including
spiral arms, out to a redshift of around z~2.5 in several passbands.

ACS/WFC 9788

A Narrow-band Snapshot Survey of Nearby Galaxies

We propose to use ACS/WFC to conduct the first comprehensive HST
narrow-band {H- alpha + [N II]} imaging survey of the central regions
of nearby bulge-dominated disk {S0 to Sbc} galaxies. This survey will
cover, at high angular resolution extending over a large field, an
unprecedented number of galaxies representing many different
environments. It will have important applications for many
astrophysical problems of current interest, and it will be an
invaluable addition to the HST legacy. The observations will be
conducted in snapshot mode, drawing targets from a complete sample of
145 galaxies selected from the Palomar spectroscopic survey of nearby
galaxies. Our group will use the data for two primary applications.
First, we will search for nuclear emission-line disks suitable for
future kinematic measurements with STIS, in order to better constrain
the recently discovered relations between black hole mass and bulge
properties. Preliminary imaging of the type proposed here must be
done, sooner or later, if we are to make progress in this exciting new
field. Second, we will investigate a number of issues related to
extragalactic star formation. Specifically, we will systematically
characterize the properties of H II regions and super star clusters on
all galactic scales, from circumnuclear regions to the large-scale
disk.

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 9846

The Origins of Sub-stellar Masses: Searching for the End of the IMF

Is there a preferred scale that defines the end of the IMF? We propose
to test this hypothesis by conducting a deep spectroscopic survey of
extremely low mass objects in the embedded young cluster associated
with NGC1333. At a distance of only 300pc, this cluster is one of the
nearest examples of a dense young cluster. We will be able to obtain
R=200 spectra and photometry for 40-60 cluster members with masses
between 5-40 Jupiter masses at an age of 1 Myr observed through
A{v}<10 mag. This will enable us to estimate temperatures and
luminosities for all sources detected in the survey. We will compare
their positions in an H-R diagram to PMS evolutionary tracks in order
to estimate their ages and masses. For a solar metallicity cloud at a
temperature of 10 K, the minimum mass for fragmentation is thought to
be 10 Jupiter masses. A statistically significant sample of objects
detected below this limit would challenge the role of hierarchical
fragmentation in limiting substellar masses. The proximity of this
cluster combined with the unique sensitivity, wavelength coverage, and
multi-object spectroscopic capability of NICMOS on HST make this
experiment possible.

S/C 10439

2-Gyro T2G On-Orbit Test: Pointing and Data Management

This part of the 2-gyro T2G On-Orbit Test contains the visits that
will manage the point of the spacecraft as well as the engineering
data recording.

S/C 10440

2-Gyro T2G On-Orbit Test: FHST Activities

This proposal contains the FHST activities that will be scheduled
during the on-orbit test. Activities include FHST shutter opens and
closes, FHST Availability on and off, On- Board Attitude Determination
{OBAD or OAD} without the following attitude correction. All these
visits will be scheduled as parallels on top of the pointed visits in
proposal 10439.

WFPC2 10360

WFPC2 CYCLE 13 INTERNAL MONITOR

This calibration proposal is the Cycle 13 routine internal monitor for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety of internal exposures are obtained in order to provide a
monitor of the integrity of the CCD camera electronics in both bays
{gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a
monitor for possible buildup of contaminants on the CCD windows.

FLIGHT OPERATIONS SUMMARY:

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

COMPLETED OPS REQs:

  • 17313-0 TMDIAGs for Rate & Position Data @ 321/15:20z
  • 17316-0 Modify FHST Moving Target DB Limits @ 321/16:38z
  • 17314-0 TMDIAGs for Rate & Position Data @ 321/16:55z
  • 17317-0 ARU/PRT @ 321/19:16z
  • 17318-0 Real-Time Map @ 321/23:31z
  • 17319-0 ARU/PRT @ 322/00:13z
  • 17311-1 Two Gyro Test Day 1 Flight Plan @ 322/00:20z

OPS NOTES EXECUTED: None

                          SCHEDULED     SUCCESSFUL    FAILURE TIMES
FGS Gsacq               06                       06
FGS Reacq                01                       01
FHST Update             11                       11
LOSS of LOCK

SIGNIFICANT EVENTS:

Successfully completed the Two Gyro Science M2G/T2G on-orbit test, Day
1 @ 321/23:28Z (OR 17311-1). An initial assessment of performance
indicates all modes tested (M2G, T2G, and OBAD without maneuvers) were
within expected levels. In summary, all M2G and T2G modes, including
mode transitions, were successfully tested, all showing nominal
performance. Three large angle slews were successfully performed (yaw
axis only) in the M2G mode followed by the successful commanding of
OBAD in the T2G mode. Residual attitude errors, after the slews, were
better than expected, ranging from 0.7 to 0.4 degrees. The maximum
attitude error and attitude error profile for the test will be
determined from post-processing data following the engineering
recorder playback.

Re-entered 3-gyro mode @ 321/23:38Z and, following a planned ARU/PRT,
the GS acquisition @ 321/01:31Z was successful with nominal attitude
errors and gyro biases. No gyro bias updates were needed prior to
resuming science, at which point the autonomous on-board bias
algorithm resumed updates.

SpaceRef staff editor.