NASA Hubble Space Telescope Daily Report #3919

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT    # 3919

PERIOD COVERED: UT August 05 – 7, 2005 (DOY 217-219)

OBSERVATIONS SCHEDULED

ACS/HRC 10391

Wavelength and Flux Calibration of the ACS prisms

The wavelength calibration of the SBC {PR110L and PR130L} and HRC
{PR200L} prisms will be established by observing a planetary nebula in
the LMC and QSOs at carefully selected redshifts. Flux calibrations
will be derived for each prism by observing white dwarf standards.

ACS/HRC 10545

Icy planetoids of the outer solar system

Early HST studies of satellites of Kuiper belt object focussed on the
50-200 km objects that were the largest known at the time. In the past
3 years we have discovered a population of much more rare and much
larger {500-2000+ km} icy planetoids in the Kuiper belt. These objects
are the largest and brightest known in the Kuiper belt and, in the era
when we now know of more than 1000 Kuiper belt objects, these few
planetoids are likely to be the focus of much of the research on
physical properties of the outer solar system for years to come. We
are currently engaged in an intensive program involving Spitzer, Keck,
and other telescopes to study the physical and dynamical properties of
this new population. HST is uniquely capable of addressing one
parameter fundamental to completing the physical picture of these
planetoids: the existence and size of any satellites. The detection
and characterization of satellites to these large planetoids would
allow us to address unique issues critical to the formation and
evolution of the outer solar system, including the measurement of
densities, internal properties, sizes and shapes of these objects, the
study of binary formation as a function of primary size, and the
context of the Pluto-Charon binary. For these bright objects, a
satellite search takes less than a full orbit, allowing the
opportunity for a new project on UV spectroscopy of the planetoids to
piggyback at no added time cost. This poorly explored spectral range
has the potential to show unique signatures of trapped gasses,
cosmochemically important ices, and complex organic materials.

ACS/HRC 10623

HST Optical Snapshot Survey of Intermediate Redshift Ultraluminous
Infrared Galaxies

Ultraluminous infrared galaxies {ULIGs} are commonly believed to be a
transitory phase in the evolution of disk galaxy mergers into QSOs.
However, a recently reported discrepancy between the morphological and
structural properties of z < 0.13 ULIGs and z = 0.12-0.25 QSOs with M{V} < -23.5 has cast doubt on their evolutionary connection. We propose an ACS snapshot survey of a sample of 39 ULIGs with z = 0.35-1.0. These galaxies are the best suited for comparison with luminous z=0.12-0.25 QSOs because {1} they are at larger lookback times than local ULIGs, and thus are likely representative of the systems that evolve into lower redshift luminous QSOs, {2} they have luminosities comparable to luminous QSOs and, {3} they are selected in a manner that biases the sample towards harboring imbedded AGN, and thus are the most likely precursors to optical QSOs. High resolution HST ACS images will allow a determination of galaxy morphology and reveal the presence of bright AGN. The 2-D profile of each galaxy will be modeled using GALFIT, with the AGN comprising one component of the fit where applicable to better characterize the underlying galaxy. Fundamental parameters {effective radius and surface brightness, and F814W-band magnitude} of the underlying galaxy will thus be measured and compared with the host galaxies of the luminous QSO sample. This imaging campaign will consume a modest amount of HST time, but will provide for the first time a statistically significant view of ULIGs at look-back times of 30-65% the age of the universe, and sufficient resolution and sensitivity to conduct a meaningful comparison with z=0.12-0.25 QSOs, as well as with local {z < 0.3} IRAS-detected and distant {z > 2} SCUBA-detected ULIGs.

ACS/HRC 10695

Coronagraphic Search for Disks around Nearby Stars

This is a search for debris disks around nearby G-type stars that have
infrared excesses. The ACS coronagraph will be used with filter F606W.

ACS/HRC/WFC 10389

ACS CCDs daily monitor – Cycle 13 – Part 2

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 program will be
for the entire lifetime of ACS.

ACS/WFC 10187

Direct imaging of the progenitors of massive, core-collapse supernovae

Modern supernovae searches in the nearby Universe are discovering
large numbers of SNe which have massive star progenitors {Types II, Ib
and Ic}. The extensive HST image archives of galaxies within ~20Mpc
enables their individual bright stellar content to be resolved. As
massive, evolved stars are the most luminous single objects in a
galaxy, the progenitors of core-collapse SNe should be directly
detectable on pre-explosion images. In our ongoing HST programme we
have detected the first red supergiant progenitor of a normal type II
supernova, shown that SN 1993J came from a binary system, and set
direct mass-limits on three other type II supernovae progenitors.
These discoveries are providing strong constraints on theoretical
models of pre- supernova stellar evolution that predict which stars
produce which type of supernovae. We request time to continue this
successful project, and require ACS observations of future SNe which
are discovered in galaxies closer than 20Mpc which have pre-explosion
HST archive images available. These observations will allow the SNe to
be precisely positioned on the pre- explosion frames with the required
astrometric accuracy of around 0.05″, and provide 3-colour photometry
of the surrounding stellar populations for reddening estimations. The
goal of this project is to directly identify the progenitor stars of
core-collapse supernovae. We will compare the results to our own
stellar evolutionary tracks in order to determine masses or
restrictive mass-limits for the progenitors.

ACS/WFC 10258

Tracing the Emergence of the Hubble Sequence Among the Most Luminous
and Massive Galaxies

There is mounting evidence that the redshift range 1 < z < 2 was an important era when massive galaxies assembled their stellar content and assumed their present--day morphologies. Despite extensive HST imaging surveys, however, there is very little data in the optical rest frame {i.e., observed near--infrared} on the morphologies of the most luminous galaxies at these redshifts. We propose to image a carefully selected set of 20 of the most luminous, K--band selected GOODS galaxies at 1.3 < z < 2, using NICMOS camera 2. This offers diffraction--limited, critically sampled imaging at 1.6 microns to ensure the best angular resolution for comparison to ACS. The galaxies are chosen to span a simple 4--fold parameter space of morphological and spectral type, in order to provide the most information about the variety of massive galaxy properties in this redshift range. We will investigate the emergence of large scale--length disks, stable spiral structure, mature bulges with red stellar populations, central bar structures, the incidence of disturbed morphology, the existence {or lack thereof} of blue ellipticals, and other questions that concern the evolution and maturation of the brightest, largest, and most massive ordinary galaxies in this critical redshift range.

ACS/WFC 10626

A Snapshot Survey of Brightest Cluster Galaxies and Strong Lensing to
z = 0.9

We propose an ACS/WFC snapshot survey of the cores of 150 rich galaxy
clusters at 0.3 < z < 0.9 from the Red Sequence Cluster Survey {RCS}. An examination of the galaxian light in the brightest cluster galaxies, coupled with a statistical analysis of the strong-lensing properties of the sample, will allow us to contrain the evolution of both the baryonic and dark mass in cluster cores, over an unprecedented redshift range and sample size. In detail, we will use the high- resolution ACS images to measure the metric {10 kpc/h} luminosity and morphological disturbances around the brightest clusters galaxies, in order to calibrate their accretion history in comparison to recent detailed simulations of structure formation in cluster cores. These images will also yield a well-defined sample of arcs formed by strong lensing by these clusters; the frequency and detailed distribution {size, multiplicity, redshifts} of these strong lens systems sets strong constraints on the total mass content {and its structure} in the centers of the clusters. These data will also be invaluable in the study of the morphological evolution and properties of cluster galaxies over a significant redshift range. These analyses will be supported by extensive ongoing optical and near-infrared imaging, and optical spectroscopy at Magellan, VLT and Gemini telescopes, as well as host of smaller facilities.

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.

ACS/WFC/WFPC2 10558

Archaeology of Fossil Galaxy Groups

Fossil groups are concentrations of dark matter with masses and x-ray
luminosities comparable to those of an entire group of galaxies, but
whose light is dominated by a single, isolated, large elliptical
galaxy. The origin of these systems remains a puzzle: they may be the
end products of complete merging of galaxies within once normal
groups, or they might originate from a very unusual galaxy luminosity
function in those regions that inhibits the formation of
moderate-sized galaxies. We propose the first study of the globular
cluster populations of the dominant elliptical galaxies in fossil
galaxy groups, which will provide important new insights into their
origin.

NIC1/NIC2/NIC3 10721

NICMOS dark current tests for newly implemented SPARS sequences

On June 12, 2005, 4 new NICMOS multiaccum sequences {SPARS4, SPARS16,
SPARS32, SPARS128} were implemented. The purpose of this observation
is to measure the dark currents for these new multiaccum sequences for
all three NICMOS detectors.

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.

WFPC2 10356

WFPC2 Cycle 13 Decontaminations and Associated Observations

This proposal is for the monthly WFPC2 decons. Also included are
instrument monitors tied to decons: photometric stability check, focus
monitor, pre- and post-decon internals {bias, intflats, kspots, &
darks}, UV throughput check, VISFLAT sweep, and internal UV flat
check. FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

9908 – GSAcq (2,3,3) results in finelock backup (3,0,3) scan step lmt
exc on FGS-2 @ 218/2314z GSAcq(2,3,3)scheduled at
218/23:14:50-23:22:09 resulted in finelock backup (3,0,3)using FGS-3
due to scan step limit exceeded on FGS-2 during walkdown.

9909 – GSAcq (2,1,2) results in finelock backup (1,0,1) scan step lmt
exc on FGS-2 @ 220/0043z GSAcq(2,1,2)scheduled at
220/00:43:39-00:50:51 resulted in finelock backup (1,0,1)using FGS-1
due to scan step limit exceeded on FGS-2 during walkdown. Prior FM
update showed the small errors

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                              SCHEDULED     SUCCESSFUL 
 FGS Gsacq                  29                      29 
 FGS Reacq                  21                      21 
 FHST Update               43                      43 
 LOSS of LOCK 

SIGNIFICANT EVENTS: (None)