Daily # 4256

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4256

PERIOD COVERED: UT December 08,09,10, 2006 (DOY 342,343,344)

OBSERVATIONS SCHEDULED

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.

ACS/HRC 11053

Earth Flats

Sky flats will be obtained by observing the bright Earth with the HRC
and WFC. These observations will be used to verify the accuracy of the
latest pipeline flats and to monitor any changes. Weekly coronagraphic
monitoring is required to assess the changing position of the spots.

ACS/HRC 11041

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. For cycle 15 the program will cover 18
months 12.1.06-05.31.08 and it has been divied into three different
proposal each covering six months. The three proposals are
11041-11042-11043.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and
highly non-uniform archive, making comprehensive comparative studies
among galaxies essentially impossible. We propose to secure HST's
lasting impact on the study of nearby galaxies by undertaking a
systematic, complete, and carefully crafted imaging survey of ALL
galaxies in the Local Universe outside the Local Group. The resulting
images will allow unprecedented measurements of: {1} the star
formation history {SFH} of a 100 Mpc^3 volume of the Universe with a
time resolution of Delta[log{t}]=0.25; {2} correlations between
spatially resolved SFHs and environment; {3} the structure and
properties of thick disks and stellar halos; and {4} the color
distributions, sizes, and specific frequencies of globular and disk
clusters as a function of galaxy mass and environment. To reach these
goals, we will use a combination of wide-field tiling and pointed deep
imaging to obtain uniform data on all 72 galaxies within a
volume-limited sample extending to ~3.5 Mpc, with an extension to the
M81 group. For each galaxy, the wide-field imaging will cover out to
~1.5 times the optical radius and will reach photometric depths of at
least 2 magnitudes below the tip of the red giant branch throughout
the limits of the survey volume. One additional deep pointing per
galaxy will reach SNR~10 for red clump stars, sufficient to recover
the ancient SFH from the color-magnitude diagram. This proposal will
produce photometric information for ~100 million stars {comparable to
the number in the SDSS survey} and uniform multi-color images of half
a square degree of sky. The resulting archive will establish the
fundamental optical database for nearby galaxies, in preparation for
the shift of high-resolution imaging to the near-infrared.

ACS/WFC/WFPC2 10890

Morphologies of the Most Extreme High-Redshift Mid-IR-Luminous
Galaxies

The formative phase of the most massive galaxies may be extremely
luminous, characterized by intense star- and AGN-formation. Till now,
few such galaxies have been unambiguously identified at high redshift,
restricting us to the study of low-redshift ultraluminous infrared
galaxies as possible analogs. We have recently discovered a sample of
objects which may indeed represent this early phase in galaxy
formation, and are undertaking an extensive multiwavelength study of
this population. These objects are bright at mid-IR wavelengths
{F[24um]0.8mJy}, but deep ground based imaging suggests extremely
faint {and in some cases extended} optical counterparts {R~24-27}.
Deep K-band images show barely resolved galaxies. Mid-infrared
spectroscopy with Spitzer/IRS reveals that they have redshifts z ~
2-2.5, suggesting bolometric luminosities ~10^{13-14}Lsun! We propose
to obtain deep ACS F814W and NIC2 F160W images of these sources and
their environs in order to determine kpc-scale morphologies and
surface photometry for these galaxies. The proposed observations will
help us determine whether these extreme objects are merging systems,
massive obscured starbursts {with obscuration on kpc scales!} or very
reddened {locally obscured} AGN hosted by intrinsically low-luminosity
galaxies.

ACS/WFC 10886

The Sloan Lens ACS Survey: Towards 100 New Strong Lenses

As a continuation of the highly successful Sloan Lens ACS {SLACS}
Survey for new strong gravitational lenses, we propose one orbit of
ACS-WFC F814W imaging for each of 50 high- probability strong
galaxy-galaxy lens candidates. These observations will confirm new
lens systems and permit immediate and accurate photometry, shape
measurement, and mass modeling of the lens galaxies. The lenses
delivered by the SLACS Survey all show extended source structure,
furnishing more constraints on the projected lens potential than
lensed-quasar image positions. In addition, SLACS lenses have lens
galaxies that are much brighter than their lensed sources,
facilitating detailed photometric and dynamical observation of the
former. When confirmed lenses from this proposal are combined with
lenses discovered by SLACS in Cycles 13 and 14, we expect the final
SLACS lens sample to number 80--100: an approximate doubling of the
number of known galaxy-scale strong gravitational lenses and an
order-of-magnitude increase in the number of optical Einstein rings.
By virtue of its homogeneous selection and sheer size, the SLACS
sample will allow an unprecedented exploration of the mass structure
of the early-type galaxy population as a function of all other
observable quantities. This new sample will be a valuable resource to
the astronomical community by enabling qualitatively new strong
lensing science, and as such we will waive all but a short {3-month}
proprietary period on the observations.

ACS/HRC 10878

An ACS Prism Snapshot Survey for z~2 Lyman Limit Systems

We propose to conduct a spectroscopic survey of Lyman limit absorbers
at redshifts 1.7 z 2.2, using ACS/HRC and the PR200L prism. We
have selected 100 quasars at 2.3 z 2.6 from the Sloan Digital Sky
Survey Spectroscopic Quasar sample, for which no BAL signature is
found at the QSO redshift and no strong metal absorption lines are
present at z 2.3 along the lines of sight. The survey has three main
observational goals. First, we will determine the redshift frequency
dN/dz of the LLS over the column density range 16.3 log N_HI 20.3
cm^-2. Second, we will measure the column density frequency
distribution f{N} for the partial Lyman limit systems {PLLS} over the
column density range 16.3 log N_HI 17.5 cm^-2. Third, we will
identify new sightlines for measurements of the primordial D/H ratio.
With this survey, we will also constrain two key quantities of
cosmological relevance: First, the measurements of dN/dz for optically
thick LLS and f{N} for the PLLS are critical to estimating the
attenuation of extragalactic ionizing sources {e.g. QSOs}. Currently,
uncertainties in dN/dz and f{N} are the greatest sources of
uncertainty for inferring the shape and intensity of the UV background
radiation field. Second, we will estimate the amount of metals in the
LLS using the f{N} and ground based observations of metal line
transitions. It is possible that a significant fraction of the
"missing metals" at z~2 are associated with these highly ionized
absorbers. Third, analysis of the LLS lends to investigations of the
interface between galaxies {i.e. the damped Lyman alpha systems} and
the intergalactic medium {i.e. the Lyman alpha forest}. This survey is
ideal for a snapshot observing program, because the on-object
integration times are less than 10 minutes, and the targets cover the
majority of the northern sky.

ACS/HRC 10877

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for
supernovae {SNe}, most notably our Lick Observatory Supernova Search
{LOSS}, have found hundreds of SNe, many of them in quite nearby
galaxies {cz 4000 km/s}. Most of the objects were discovered before
maximum brightness, and have follow-up photometry and spectroscopy;
they include some of the best-studied SNe to date. We propose to
conduct a snapshot imaging survey of the sites of some of these nearby
objects, to obtain late-time photometry that {through the shape of the
light and color curves} will help reveal the origin of their lingering
energy. The images will also provide high-resolution information on
the local environments of SNe that are far superior to what we can
procure from the ground. For example, we will obtain color-color and
color-magnitude diagrams of stars in these SN sites, to determine the
SN progenitor masses and constraints on the reddening. Recovery of the
SNe in the new HST images will also allow us to actually pinpoint
their progenitor stars in cases where pre- explosion images exist in
the HST archive. This proposal is an extension of our successful Cycle
13 snapshot survey with ACS. It is complementary to our Cycle 15
archival proposal, which is a continuation of our long-standing
program to use existing HST images to glean information about SN
environments.

NIC3 10874

Search for Extremely Faint z7 Galaxy Population with Cosmic Lenses

Deep UDF/NICMOS observations find a significant decrease in the number
of galaxy candidates between redshift z=6 and 7, but the sample at z7
is too small to draw conclusions. From our observations of 15 clusters
we have found a number of bright z-dropouts, aided by the lensing
amplification. We propose deep NICMOS observations of the best cases
of cluster centers where a rare combination of a significant lensing
effect and the richness in z-band dropouts in background may
dramatically increase the discovery rate. The NICMOS images will reach
an unprecendented depth of AB~27.8, or AB~30 in nonlensed intrinsic
magnitude, and may find many faint {~0.05L*} galaxies at z=7-10, at a
level that the UDF reaches for z~6 objects. We produce precision mass
distribution maps from weak-lensing models, which enable us to derive
the candidates' intrinsic magnitudes and their luminosity function.
The knowledge of such faint galaxy population at z7 will facilitate
the models of the IGM reionization and future JWST planning.

ACS/HRC 10867

SAINTS - Supernova 1987A INTensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova in
383 years, as it morphs into the youngest supernova remnant at age 19.
HST is a unique tool for spatially-resolved observations of the many
physical components of SN 1987A. A violent encounter is now underway
between the fastest-moving debris and the circumstellar ring: the
collision excites "hotspots" that light up suddenly. The optical,
infrared and X-ray fluxes are rising rapidly and vary significantly on
6-month time scales: regularly-spaced HST, SPITZER, and CHANDRA
observations are needed to understand the physics of these shocked
regions. In Cycle 15, the many separate hotspots may begin to fuse as
the shock fully enters the circumstellar ring. Photons from these
shocks may excite previously invisible gas outside the ring, revealing
the true extent of the mass loss that preceded the explosion of
Sanduleak -69 202. The inner debris of the explosion itself, still
excited by radioactive isotopes produced in the explosion, is now
resolved by ACS and seen to be aspherical, providing direct evidence
on the asymmetry of the explosion. Many questions about SN 1987A
remain unanswered despite our diligent efforts at observation and
analysis since the launch of HST. How did the enigmatic three rings
form? Precisely what took place in the core during the core collapse
and bounce? Is a black hole or a neutron star left behind in the
debris? The rich and deep data set from SAINTS will be a resource for
current use and for future reference to help answer these central
questions of supernova science.

NIC3 10861

An ACS Treasury Survey of the Coma cluster of galaxies

We propose to use the unique spatial resolution of HST and ACS to
construct a Treasury imaging survey of the core and infall region of
the richest local cluster, Coma. We will observe samples of thousands
of galaxies down to magnitude B=27.3 with the aim of studying in
detail the dwarf galaxy population which, according to hierarchical
models of galaxy formation, are the earliest galaxies to form in the
universe. Our initial scientific objectives a 1} A study of the
structure of the dwarf galaxies, including scaling laws, nuclear
structure and morphology, to compare with hierarchical and
evolutionary models of their formation. 2} A study of the stellar
populations from colors and color gradients, and how the internal
chemical evolution of galaxies is affected by interaction with the
cluster gaseous and galaxy environment. 3} To determine the effect of
the cluster environment upon morphological features, disks, bulges and
bars, by comparing these structure in the Coma sample with field
galaxy samples. 4} Identification of dwarf galaxy samples for further
study with the new generation of multi-object and integral-field
spectrographs on 8-10 metre class telescopes such as Keck, Subaru,
Gemini, and GTC. This is the first such survey of a nearby rich
cluster. It will provide a key database for studies of galaxy
formation and evolution, and a very needed reference for comparison
with similar galaxy surveys both in lower density environments in the
nearby universe, and in high density environments at high redshifts.

ACS/HRC 10860

The largest Kuiper belt object

The past year has seen an explosion in the discoveries of Pluto-sized
objects in the Kuiper belt. With the discoveries of the
methane-covered 2003 UB313 and 2005 FY9, the multiple satellite system
of 2003 EL61, and the Pluto-Charon analog system of Orcus and its
satellite, it is finally apparent that Pluto is not a unique oddball
at the edge of the solar system, but rather one of a family of
similarly large objects in the Kuiper belt and beyond. HST
observations over the past decade have been critical for understanding
the interior, surface, and atmosphere of Pluto and Charon. We propose
here a comprehensive series of observations designed to similarly
expand our knowledge of these recently discovered Pluto-sized and
near-Pluto-sized Kuiper belt objects. These observations will measure
objects' sizes and densities, explore the outcome of collisions in the
outer solar system, and allow the first ever look at the interior
structure of a Kuiper belt object. Our wide field survey that
discovered all of these objects is nearly finished, so after five
years of continuous searching we are finally almost complete in our
tally of these near-Pluto-sized objects. This large HST request is the
culmination of this half-decade search for new planetary-sized
objects. As has been demonstrated repeatedly by the approximately 100
previous orbits devoted to the study of Pluto, only HST has the
resolution and sensitivity for detailed study of these distant
objects.

ACS/WFC 10809

The nature of "dry" mergers in the nearby Universe

Recent studies have shown that "dry" mergers of red, bulge-dominated
galaxies at low redshift play an important role in shaping today's
most massive ellipticals. These mergers have been identified in
extremely deep ground-based images of red sequence galaxies at z ~
0.1. The ground-based images reach surface brightness limits of AB ~
29, but lack the resolution to study the morphologies of the galaxies
inside the effective radius. Here we propose to obtain ACS images of a
representative sample of 40 of these red sequence galaxies: 15 ongoing
dry mergers, 15 remnants, and 10 undisturbed objects. We will measure
the isophote shapes and ellipticities of the galaxies, their dust
content, morphological fine structure {shells and ripples}, AGN
content, and their location on the Fundamental Plane. By comparing
galaxies in different stages of the merging process we can constrain
the amount of gas associated with these red mergers, the effect of
active nuclei, and track structural changes. As two galaxies can be
observed in a single orbit 20 orbits are requested to observe the 40
galaxies.

ACS/HRC 10806

Accretion in the closest binary systems known

Recently, three variable stars have been identified as likely
accreting binary systems with ultra- short orbital periods. Optical
and X-ray observations have revealed periodicities of 5-10 minutes,
making them the closest binaries known as well as strong sources of
gravitational wave emission. Such short-period accreting binaries form
the cornerstone to our understanding of binary formation and
evolution, in particular of the large double white dwarf population in
our galaxy, a candidate progenitor population for Type Ia supernovae.
We propose to obtain the first UV spectroscopy of these objects using
the ACS prisms in order to {i} determine the temperature of the
primary and the composition of their donor stars, {ii} correlate the
UV variability with other wavebands and determine if the periods are
indeed orbital. These UV observations are essential in order to
unequivocally determine whether these are indeed the most compact
binaries known.

NIC2, ACS/WFC 10802

SHOES-Supernovae, HO, for the Equation of State of Dark energy

The present uncertainty in the value of the Hubble constant {resulting
in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at
redshifts exceeding 1 are now the leading obstacles to determining the
nature of dark energy. We propose a single, integrated set of
observations for Cycle 15 that will provide a 40% improvement in
constraints on dark energy. This program will observe known Cepheids
in six reliable hosts of Type Ia supernovae with NICMOS, reducing the
uncertainty in H_0 by a factor of two because of the smaller
dispersion along the instability strip, the diminished extinction, and
the weaker metallicity dependence in the infrared. In parallel with
ACS, at the same time the NICMOS observations are underway, we will
discover and follow a sample of Type Ia supernovae at z 1. Together,
these measurements, along with prior constraints from WMAP, will
provide a great improvement in HST's ability to distinguish between a
static, cosmological constant and dynamical dark energy. The Hubble
Space Telescope is the only instrument in the world that can make
these IR measurements of Cepheids beyond the Local Group, and it is
the only telescope in the world that can be used to find and follow
supernovae at z 1. Our program exploits both of these unique
capabilities of HST to learn more about one of the greatest mysteries
in science.

FGS 10614

Internal Structure and Figures of Binary Asteroids

The goal of this proposal is to obtain very important information on
the internal structure of a number of asteroids, and insight on the
gravitational reaccumulation-process after a catastrophic disruptive
collision. High resolutions observations with the HST/FGS
interferometer are proposed to obtain high precision data for the
topographic shape and size of a number of selected asteroids. Here we
focus on objects with satellites, hence with known masses, so that the
bulk density and porosity will be derived in the most accurate manner.
This will yield plausible estimates on the internal properties of the
objects, test wether they are close or not to figures of equilibrium
{in terms of shape and adimensional rotational frequency}, and provide
estimates of their relative density. The HST/FGS in interferometric
mode is an ideal facility to carry out this program.

ACS/WFC 10237

Low-Ionization BALs: Evolution or Orientation?

We propose to test the hypothesis that Low-Ionization Broad Absorption
Line Quasars {LoBALs} represent a special stage of quasar evolution:
young quasars in systems with strong interaction and star-formation.
We will carry out high resolution imaging using ACS/WFC and NICMOS to
measure the properties of the host galaxies of four LoBAL quasars at z
= 0.9 - 2.0 that show strong overlapping FeII absorption troughs. The
ACS imaging will be carried out in the passband with the strongest BAL
absorption, acting as a natural coronagraph. This results in a
reduction of quasar light by a factor of 15 - 26 in these passbands,
providing arguably the best view of the host galaxies of luminous,
high-redshift quasars. This method allows efficient detection and
detailed modeling of the host galaxy morphology in the rest-frame
ultraviolet, which is most sensitive to star formation and galaxy
interaction. We will also use NICMOS imaging to measure the rest-frame
light from the host galaxy to probe the old stellar populations where
the host galaxy is likely to be brighter. It has been suggested that
LoBALs might not be explained simply as an orientation effect but
rather as an early phase of quasar evolution. Such a phase is
typically associated with large amounts of dust and gas, and young
galaxies with strong star formation. With HST observations, we will
study the color and morphology of the FeLoBAL quasar host galaxies,
and measure the age of their dominant stellar populations. We will
also measure the density of close companions, and, in particular, look
for signs of ongoing or recent mergers. These measurements will be
compared to those of control samples of normal quasars at similar
redshift. If LoBALs are indeed young systems, then their host galaxies
are expected to show stronger interactions and merger activity,
younger stellar ages, and regions with strong star formation. If the
LoBAL host galaxies show no significant difference from those of
normal quasars, it will support the view that LoBAL quasars are not a
distinct population and that all quasars have BAL outflows along some
lines of sight.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10550 - GSAcq(2,3,2) failed to RGA Hold (Gyro Control)

Upon acquisition of signal at 342/10:31:46, the GSAcq(2,3,2) scheduled
at 342/08:57:20 -09:05:25 was observed to have failed to RGA Hold due
to search radius limit exceeded on FGS-2. One 486 ESB "a05" (FGS
Coarse Track failed - Search Radius Limit Exceeded) was received.
Pre-acquisition OBADs (RSS) attitude error corrections values not
available pending future ETR Dump due to LOS.

10551 - GSAcq (2,1,2) failed due to Scan Step Limit Exceeded on FGS

At AOS 342/20:03:25 GSAcq (2,1,2) scheduled from 342/19:44:42-19:51:57
failed to RGA control due to scan step limit exceeded on FGS 2. OBAD
#1: V1 15.18, V2 -2510.66, V3 542.69, RSS 2569.75 OBAD #2: V1, -2.28,
V2 12.47, V3 2.90, RSS 13.01 OBAD MAP: V1 0.62, V2 5.71, V3 -3.33, RSS
6.64

10552 - GSAcq(2,1,2) Loss of Lock

While HST was guiding under two FGSs following successful GSAcq(2,1,2)
of 343/00:59:25 FGS-1 the Sub-dominant guider lost lock at
343/03:07:25 following a Type 3 Slew scheduled at 343/02:57:56 -
02:58:06. The mnemonic QDVFGSM0 (FGS Attitude Error Angle) broke limit
at 343/03:07:22 with a value of -0.000601679 radians. The spacecraft
entered M2G_MODE at 343/03:07:32. The TERM EXP was not scheduled until
343/04:52:25.

10553 - REacq(1,2,2) failed due to scan step limit exceeded.

REacq(1,2,2) scheduled at 344/14:51:03 failed due to scan step limit
exceeded on FGA 1. OBAD1 showed errors of V1= -49.56, V2=-3489.72,
V3=-42.59, RSS=3490.33. OBAD2 showed errors of V1=-3.26, V2=-6.41,
V3=-2.85, and RSS=7.74.

The REacq(1,2,2) at 344/16:26:58 also failed due to scan step limit
exceeded on FGS 1 at 16:30:18. OBAD1 was during LOS. OBAD2 showed
errors of V1=-0.26, V2=-1.32, V3=2.56, RSS= 2.89.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSacq 21 19
FGS REacq 20 18
OBAD with Maneuver 84 84

SIGNIFICANT EVENTS: (None)