Daily #3941

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3941

PERIOD COVERED: UT September 08, 2005 (DOY 251)

OBSERVATIONS SCHEDULED

ACS/HRC/WFC 10370

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 12 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 will now
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 10548

Near-UV Snapshot Survey of Low Luminosity AGNs

Low-luminosity active galactic nuclei {LLAGNs} comprise ~30% of all
bright galaxies {B12.5} and are the most common type of AGN. These
include low-luminosity Seyfert galaxies, LINERs, and transition-type
objects {TOs, also called weak-[OI] LINERs}. What powers them is still
at the forefront of AGN research. To unveil the nature of the central
source we propose a near-UV snapshot survey of 50 nearby LLAGNs using
ACS/HRC and the filter {F330W}, a configuration which is optimal to
detect faint star forming regions around their nuclei. These images
will complement optical and near-IR images available in the HST
archive, providing a panchromatic atlas of the inner regions of these
galaxies, which will be used to study their nuclear stellar
population. Our main goals are to: 1} Investigate the presence of
nuclear unresolved sources that can be attributed to an AGN; 2}
Determine the frequency of nuclear and circumnuclear stellar clusters,
and whether they are more common in Transition Objects {TOs} than in
LINERs; 3} Characterize the sizes, colors, luminosities, masses and
ages of these clusters; 4} Derive the luminosity function of star
clusters and study their evaporation over time in the vicinity of
AGNs. Finally, the results of this project will be combined with those
of a previous similar one for Seyfert galaxies in order to compare the
nature of the nuclear sources and investigate if there could be an
evolution from Seyferts to TOs and LINERs. By adding UV images to the
existing optical and near-IR ones, this project will also create an
extremely valuable database for astronomers with a broad range of
scientific interests.

ACS/WFC 10592

An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in
the Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared
selected galaxies exceeds that of optically selected galaxies. These
`luminous infrared galaxies' {LIRGs} are primarily interacting or
merging disk galaxies undergoing enhanced star formation and Active
Galactic Nuclei {AGN} activity, possibly triggered as the objects
transform into massive S0 and elliptical merger remnants. We propose
ACS/WFC imaging of a complete sample of 88 L_IR 10^11.4 L_sun
luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample
{RBGS: i.e., 60 micron flux density 5.24 Jy}. This sample is ideal
not only in its completeness and sample size, but also in the
proximity and brightness of the galaxies. The superb sensitivity,
resolution, and field of view of ACS/WFC on HST enables a unique
opportunity to study the detailed structure of galaxies that sample
all stages of the merger process. Imaging will be done with the F439W
and F814W filters {B and I-band} to examine as a function of both
luminosity and merger state {i} the evidence at optical wavelengths of
star formation and AGN activity and the manner in which instabilities
{bars and bridges} in the galaxies may funnel material to these active
regions, {ii} the relationship between star formation and AGN
activity, and {iii} the structural properties {AGN, bulge, and disk
components} and fundamental parameters {effective radius and surface
brightness} of LIRGs and their similarity with putative evolutionary
byproducts {elliptical, S0 and classical AGN host galaxies}. This HST
survey will also bridge the wavelength gap between a Spitzer imaging
survey {covering seven bands in the 3.6-160 micron range} and a GALEX
UV imaging survey of these galaxies, but will resolve complexes of
star clusters and multiple nuclei at resolutions well beyond the
capabilities of either Spitzer or GALEX. The combined datasets will
result in the most comprehensive multiwavelength study of interacting
and merging galaxies to date.

ACS/WFC 10634

White Dwarf Cooling Physics: Calibrating the Clock

We know approximate ages for the Galactic disk from white dwarf
cooling theory applied to local white dwarfs and for the Galactic halo
from main sequence stellar evolutionary theory applied to star
clusters. However, the two chronometers are not cross-calibrated to
the same absolute scale; our observations will perform this
cross-calibration and improve the precision of both chronometers. We
propose to use HST/ACS photometry of white dwarfs in five moderately
old open cluster {0.6-2.2 Gyr}, along with all available up-to-date
white dwarf interior and atmosphere models and a powerful new
statistical approach, to compare main sequence evolutionary theory and
white dwarf cooling theory. This comparison will be done in such a
manner as to test white dwarf crystallization and carbon/oxygen phase
separation, as well as main sequence models in the range where they
are sensitive to the degree of core overshooting and where PP burning
transitions to CNO burning. This confrontation is essential before we
can accurately and precisely apply white dwarf cosmochronometry to the
disk and halo field populations and to globular clusters. Past support
by HST for white dwarf ages in globular clusters {123 orbits for M4
and a similarly large scheduled campaign for NGC 6397} will only be
fully levereged by ensuring that both stellar chronometers are
calibrated to the same age scale. Only then can white dwarf
chronometers live up to their potential as fundamental, independent,
and new age estimators for the Galaxy.

ACS/WFC/NIC3/WFPC2 10530

Probing Evolution And Reionization Spectroscopically {PEARS}

While imaging with HST has gone deep enough to probe the highest
redshifts, e.g. the GOODS survey and the Ultra Deep Field,
spectroscopic identifications have not kept up. We propose an ACS
grism survey to get slitless spectra of all sources in a wide survey
region {8 ACS fields} up to z =27.0 magnitude, and an ultradeep field
in the HUDF reaching sources up to z =28 magnitude. The PEARS survey
will: {1} Find and spectrocopically confirm all galaxies between
z=4-7. {2} Probe the reionization epoch by robustly determining the
luminosity function of galaxies and low luminosity AGNs at z = 4 - 6.
With known redshifts, we can get a local measure of star formation and
ionization rate in case reionization is inhomogeneous. {3} Study
galaxy formation and evolution by finding galaxies in a contiguous
redshift range between 4 z 7, and black hole evolution through a
census of low-luminosity AGNs. {4} Get a robust census of galaxies
with old stellar populations at 1 z 2.5, invaluable for checking
consistency with heirarchical models of galaxy formation. Fitting
these galaxies' spectra will yield age and metallicity estimates. {5}
Study star-formation and galaxy assembly at its peak at 1 z 2 by
identifying emission lines in star-forming galaxies, old populations
showing the 4000A break, and any combination of the two. {6} Constrain
faint white dwarfs in the Galactic halo and thus measure their
contribution to the dark matter halo. {7} Derive spectro-photometric
redshifts by using the grism spectra along with broadband data. This
will be the deepest unbiased spectroscopy yet, and will enhance the
value of the multiwavelength data in UDF and the GOODS fields to the
astronomical community. To this end we will deliver reduced spectra to
the HST archives.

FGS 10610

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric
elements {perturbation orbit semi-major axis and inclination} of
extra-solar planets orbiting six stars. These companions were
originally detected by radial velocity techniques. We have
demonstrated that FGS astrometry of even a short segment of reflex
motion, when combined with extensive radial velocity information, can
yield useful inclination information {McArthur et al. 2004}, allowing
us to determine companion masses. Extrasolar planet masses assist in
two ongoing research frontiers. First, they provide useful boundary
conditions for models of planetary formation and evolution of
planetary systems. Second, knowing that a star in fact has a plantary
mass companion, increases the value of that system to future
extrasolar planet observation missions such as SIM PlanetQuest, TPF,
and GAIA.

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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.

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 11 11
FGS Reacq 2 2
OBAD with Maneuver 21 21


SIGNIFICANT EVENTS: (None)