Daily # 4217

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4217

PERIOD COVERED: UT October 11, 2006 (DOY 284)

OBSERVATIONS SCHEDULED

ACS/HRC/WFC 10733

CCD Hot Pixel Annealing

Hot pixel annealing will continue to be performed once every 4 weeks.
The CCD TECs will be turned off and heaters will be activated to bring
the detector temperatures to about +20C. This state will be held for
approximately 6 hours, after which the heaters are turned off, the
TECs turned on, and the CCDs returned to normal operating condition.
To assess the effectiveness of the annealing, a bias and four dark
images will be taken before and after the annealing procedure for both
WFC and HRC. The HRC darks are taken in parallel with the WFC darks.
The charge transfer efficiency {CTE} of the ACS CCD detectors declines
as damage due to on-orbit radiation exposure accumulates. This
degradation has been closely monitored at regular intervals, because
it is likely to determine the useful lifetime of the CCDs. We combine
the annealling activity with the charge transfer efficiency monitoring
and also merge into the routine dark image collection. To this end,
the CTE monitoring exposures have been moved into this proposal . All
the data for this program is acquired using internal targets {lamps}
only, so all of the exposures should be taken during Earth occultation
time {but not during SAA passages}. This program emulates the ACS
pre-flight ground calibration and post-launch SMOV testing {program
8948}, so that results from each epoch can be directly compared.
Extended Pixel Edge Response {EPER} and First Pixel Response {FPR}
data will be obtained over a range of signal levels for both the Wide
Field Channel {WFC}, and the High Resolution Channel {HRC}.

ACS/HRC/WFC 10758

ACS CCDs daily monitor

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. Changes from cycle 13:- The default
gain for WFC is 2 e-/DN. As before bias frames will be collected for
both gain 1 and gain 2. Dark frames are acquired using the default
gain {2}. This program cover the period May, 31 2006- Oct, 1-2006. The
first half of the program has a different proposal number: 10729.

ACS/WFC 10633

GRB afterglows and host galaxies at very high redshifts

Cosmology is beginning to constrain the nature of the earliest stars
and galaxies to form in the universe, but direct observation of
galaxies at z6 remains highly challenging due to their scarcity,
intrinsically small size, and high luminosity distance. GRB
afterglows, thanks to their extreme luminosities, offer the
possibility of circumventing these normal constraints by providing
redshifts and spectral information which couldn't be obtained by
direct observation of the hosts themselves. In addition, the
association of GRBs with massive stars means that they are a tracer of
star formation, and that their hosts are likely responsible for a
large proportion of the ionizing radiation during that era. Our
collaboration is mounting a campaign to rapidly identify and study
candidate very high redshift bursts, bringing to bear a network of 2,
4 and 8m telescopes with nIR instrumentation. The capabilities of
Swift to detect faint, distant GRBs, and to report accurate positions
for many bursts in near real-time makes our program now feasible. HST
is crucial to this endeavour, allowing us {a} to monitor the late time
afterglows and hence compare them to lower-z bursts and test the use
of GRBs as standard candles; and {b} characterise the basic
properties, luminosities, and in some cases morphologies, of the
hosts, which is essential to understanding these primordial galaxies
and their relationship to other populations.

ACS/WFC 10824

Measuring the Shape and Orientation of the Galactic Dark-Matter Halo
using Hypervelocity Stars

We propose to obtain high-resolution images of five hypervelocity
stars in the Galactic halo in order to establish the first-epoch
astrometric frame for them, as a part of a long-term program to
measure precise proper motions. The origin of these recently
discovered stars, all with positive radial velocities above 540 km/s,
is consistent only with being ejected from the deep potential well of
the massive black hole at the Galactic center. The deviations of their
space motions from purely radial trajectories probe the departures
from spherical symmetry of the Galactic potential, mainly due to the
triaxiality of the dark-matter halo. Reconstructing the full
three-dimensional space motion of the hypervelocity stars, through
astrometric proper motions, provides a unique opportunity to measure
the shape and orientation of the dark halo. The hypervelocity stars
allow measurement of the potential up to 75 kpc from the center,
independently of and at larger distances than are afforded by tidal
streams of satellite galaxies such as the Sagittarius dSph galaxy.
HVS3 may be associated with the LMC, rather then the Galactic center,
and would therefore present a case for a supermassive black hole at
the center of the LMC. We request one orbit with ACS/WFC for each of
the five hypervelocity stars to establish their current positions
relative to background galaxies. We will request a repeated
observation of these stars in Cycle 17, which will conclusively
measure the astrometric proper motions.

NIC1 11061

NICMOS Imaging of Grism Spectrophotometric Standards

In this program we will take imaging observations with all 3 cameras
with a range of filters of a significant number of stars that are part
of the spectroscopic standard star project. These stars will form the
fainter reference star backbone for programs as JWST, Sophia, and
SNAP. With this program we will: 1. Accurately calibrate relative
brightness of standard stars, which can be done more accurately with
photometry than with spectroscopy. This has been proven to be vary
valuable to straighten out the problems in the spectroscopic data
reduction and calibrations so far. 2. Increase the number of stars
over a large magnitude range to provide a more accurate cross check of
our count rate dependent non-linearity correction 3. Include stars
with radically different {very red} spectra to investigate whether the
filter curves as measured before flight are still valid by comparing
the throughput estimates from these stars to those used for the
standard calibration. 4. Repeat a few standard star observations from
cycle 7 and post-NCS installation SMOV, to increase the accuracy in
the change in sensitivity measurement with just a few observations
thanks to the long baseline.

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.

NIC2 10825

The Formation Epoch of Early-type Galaxies: Constraints from the
Fundamental Plane at z=1.3

Field and cluster surveys both show a ~50% decrease in the number of
early-type galaxies at redshifts near 1. Galaxies that have either
recently transformed into early-types or undergone star formation
should have younger appearing stellar populations. The resulting
change in the mass-to-light ratio can be detected by the offset in the
fundamental plane with redshift. We will use the fundamental plane to
test whether a significant fraction of early-type galaxies have
evidence of recent star formation, using a sample of ~20 z=1.3 cluster
and field early-type galaxies. This is 7 times larger than the sample
previously used at this redshift. We already have the high
signal-to-noise 12-20 hour long Keck spectra for these galaxies we
need for velocity dispersions. To use the fundamental plane, we
require sizes and surface brightnesses. We propose 12 orbits of NICMOS
Camera 2 imaging to measure the sizes and surface brightness
distributions of these objects in a rest-frame optical passband. These
data will provide high quality surface brightness profiles out two ~2
half-light radii, at wavelengths comparable to previous fundamental
plane studies. When combined with our spectra, the HST data will
establish the mass-to-light ratio evolution for massive early-type
galaxies from the fundamental plane. We will define the epoch of last
star formation for these z=1.3 galaxies, directly testing the claims
of strong evolution at z=1.

WFPC2 11027

Visible Earth Flats

This proposal monitors flatfield stability. This proposal obtains
sequences of Earth streak flats to construct high quality flat fields
for the WFPC2 filter set. These flat fields will allow mapping of the
OTA illumination pattern and will be used in conjuction with previous
internal and external flats to generate new pipeline superflats. These
Earth flats will complement the Earth flat data obtained during cycles
4-14.

WFPC2 11028

WFPC2 Cycle 15 UV Earth Flats

Monitor flat field stability. This proposal obtains sequences of earth
streak flats to improve the quality of pipeline flat fields for the
WFPC2 UV filter set. These Earth flats will complement the UV earth
flat data obtained during cycles 8-14.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 06 06
FGS REacq 09 09
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)