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Daily #4048



 
 
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Old February 13th 06, 02:38 PM posted to sci.astro.hubble
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Default Daily #4048

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4048

PERIOD COVERED: UT February 10,11,12, 2006 (DOY 041,042,043)

OBSERVATIONS SCHEDULED

NIC1/NIC2/NIC3 8792

NICMOS Post-SAA calibration - CR Persistence Part 3

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/WFC 10760

Black Hole X-ray Novae in M31

We have been carring out a Chandra {GO+GTO} and HST {GO} program to
find Black Hole X-ray Nova {BHXN} and their optical counterparts in
M31 for several years. To date we have found 2 dozen BHXN and 3 HST
optical counterparts for these BHXN. Our results suggest a rather high
ratio of BH to neutron star {NS} binaries, or a high duty cycle for
the BHXN. We propose to continue this program, with the goal of
determining the orbital period distribution and duty cycles of these
BHXN. Current results yield 3 orbital periods and 2 upper limits. Our
proposed observations will ~double the total number of periods and
therefore yield sufficient numbers to make a first approximation of
the orbital period distribution. The orbital period distribution is
the fundamental observable parameter any binary stellar evolution
models must match, and the duty cycle is very poorly known but
directly influences the binary lifetime. M31 is the only galaxy in
which this extra-galactic study of BHXN is feasible.

ACS/HRC/WFC 10729

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 Oct, 2 2005- May, 29-2006. The
second half of the program has a different proposal number: 10758.

NIC1/NC2/NC3 10723

Cycle 14 NICMOS dark current, shading profile, and read noise
monitoring program

The purpose of this proposal is to monitor the dark current, read
noise, and shading profile for all three NICMOS detectors throughout
the duration of Cycle 14. This proposal is a slightly modified version
of proposal 10380 of cycle 13 and 9993 of cycle12 that we cut down
some exposure time to make the observation fit within 24 orbits.

ACS/WFC 10705

Hubble Heritage Observations of NGC 5866

The Hubble Heritage team will use a single pointing of ACS WFC to
obtain B, V, and R images of NGC 5866 {M102} as part of a public
release image.

ACS/HRC 10602

A Complete Multiplicity Survey of Galactic O2/O3/O3.5 Stars with ACS

Massive stars are preferentially formed in compact multiple systems
and clusters and many of them remain spatially unresolved to date,
even in our Galaxy. This has hindered the determination of the stellar
upper mass limit. The lack of an accurate knowledge of the
multiplicity of massive stars can also introduce biases in the
calculation of the IMF at its high-mass end. We have recently used
ACS/HRC to resolve HD 93129 A, the earliest O-type star known in the
Galaxy, into a 55 mas binary. We propose here to extend that work into
a complete multi-filter ACS imaging survey of all {20} known
O2/O3/O3.5 Galactic stars to characterize the multiplicity of the most
massive stars. The data will be combined with existing FGS
observations to explore as large a parameter range as possible and to
check for consistency. We will also derive the IMF of each system
using a crowded-field photometry package and processing the data with
CHORIZOS, a code that can derive stellar temperatures, extinctions,
and extinction laws from multicolor photometry.

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 10588

The Host Galaxies of Post-Starburst Quasars

We propose to use ACS to conduct a snapshot imaging survey of
post-starburst quasars now being discovered in signficant numbers by
the Sloan Digital Sky Survey. Post-starburst quasars are broad-lined
AGN that also possess Balmer jumps and high-n Balmer absorption lines
indicative of luminous stellar populations on order of 100 Myr old.
These objects, representing a few percent of the z 0.5 quasar
population, may be an evolutionary stage in the transition of
ultraluminous infrared galaxies into normal quasars, or a type of
galaxy interaction that triggers both star formation and nuclear
activity. These sources may also illustrate how black hole mass/bulge
mass correlations arise. Ground-based imaging of individual
poststarburst quasars has revealed merger remnants, binary systems,
and single point sources. Our ACS snapshots will enable us to
determine morphologies and binary structure on sub-arcsecond scales
{surely present in the sample}, as well as basic host galaxy
properties. We will be looking for relationships among morphology,
particularly separation of double nuclei, the starburst age, the
quasar black hole mass and accretion rate, that will lead to an
understanding of the triggering activity and mutual evolution. This
project will bring quantitative data and statistics to the previously
fuzzy and anecdotal topic of the "AGN-starburst connection" and help
test the idea that post-starburst quasars are an early evolutionary
stage of normal quasars.

ACS/WFC 10576

An ACS Imaging Survey of the Galaxies Hosting Strong Mg II Absorption

Strong MgII absorbers {with rest-frame absorption equivalent width
W_MgII 0.3 A} at redshift z 1 are known to arise in extended
gaseous halos around luminous galaxies. Detailed absorption line
studies based on high-solution spectra of background quasars yield
tight constraints on the metallicity, ionization state, and kinematics
of the gaseous clouds. But whether they originate in gas accreted from
surrounding satellite galaxies or outflows associated with active
starburst in the host galaxies remains unclear. We have recently
completed a search of the Sloan Digital Sky Survey data archive for
strong MgII absorbers and identified over 1000 new systems that are
previously unknown. A subset of these MgII absorbers with W_MgII 1.8
A exhibit extreme kinematics with velocity widths {exceeding 200 km/s}
in our follow-up echelle spectra. Their dynamics are consistent with
various scenarios that include gas accretion {with speeds exceeding
the virial velocity} and starburst outflows {possibly driven by recent
merger events}. Independent of their exact nature, it is clear that
strong MgII systems serve as signposts to galactic halos with extreme
gas dynamics. Here we propose to conduct a snapshot survey of galaxies
in the fields toward high-redshift quasars with known, strong MgII
absorbers at 0.5 z 2. We plan to obtain high spatial-resolution
ACS/WFC images of 60 fields to uncover galaxies fainter than L* at the
redshifts of these absorbers and study their morphology. We will
complement the HST observations with follow-up spectroscopic
observations and IR images acquired at the Keck and Magellan
Observatories to for redshift identifications and for measuring
broad-band colors. We will investigate the correlation between
absorption line kinematics and galaxy morphology. In particular, we
will address whether on-going mergers is responsible for the extreme
dynamics observed in MgII absorption based on their rest-frame
ultraviolet morphology.

ACS/HRC 10572

Resolving M32's Main Sequence: A Critical Test for Stellar Population
Studies

We propose to observe the M32 main-sequence turnoff {MSTO} with deep
ACS/HRC B and V images. Only the superior resolution and blue
sensitivity of ACS/HRC make this possible. M32 is the only elliptical
galaxy close enough to allow direct observation of its MSTO - it is a
vital laboratory for deciphering the stellar populations of all other
elliptical galaxies, which can only be studied by the spectra of their
integrated light, given their greater distances. Major questions about
M32's star formation history remain unanswered. Spectral studies
suggest that M32 underwent a recent burst of star formation 3 to 8
billion years ago; observation of the M32 MSTO will confirm this
directly. In the process, ACS will easily resolve more luminous
components: hot blue stars, luminous, intermediate-age red clump and
AGB stars, and any extended blue horizontal branch. These detailed
CMDs will provide a direct comparison with population synthesis models
for M32, providing a bridge to studies of the integrated light of more
distant elliptical galaxies, a crucial ingredient for understanding
their star formation histories. As M32 is projected against the edge
of the M31 disk, an essential part of our proposal includes deep
observation of an M31 disk field to allow the M32 photometry to be
background corrected. These observations will reveal the star
formation history of M31's outer disk and are thus of interest in
their own right.

ACS/HRC 10557

Probing Asteroid Families for Evidence of Ultraviolet Space Weathering
Effects

We propose six HST orbits to obtain UV reflectance spectra covering
200-460 nm of two Vesta asteroid family members, asteroid 832 Karin,
and two Karin family members. These observations extend work done
under a Cycle 13 AR grant, where we analyzed all of the existing IUE
and HST S-class asteroids in the MAST database to investigate the
effects of space weathering at UV wavelengths. Our hypothesis is that
the manifestation of space weathering at UV wavelengths is a spectral
bluing, in contrast with a spectral reddening at visible-NIR
wavelengths, and that UV wavelengths can be more sensitive to
relatively small amounts of weathering than longer wavelengths. The
proposed observations will address two objectives: {1} Measure the
UV-visible spectra of 832 Karin and two members of the young Karin
family {absolute age of 5.8 My}, in order to determine whether
intermediate space weathering is observable in objects likely pristine
when they originated from the interior of Karin's pa rent body. {2}
Measure the UV-visible spectra of two members of the Vesta family to
compare with our analysis of IUE Vesta spectra. These observations
will probe Vesta's interior, and test our hypothesis by contrasting
the apparent amount of alteration on the surfaces of Vestoids with
excavated material on Vesta.

ACS/WFC 10543

Microlensing in M87 and the Virgo Cluster

Resolving the nature of dark matter is an urgent problem. The results
of the MACHO survey of the Milky Way dark halo toward the LMC indicate
that a significant fraction of the halo consists of stellar mass
objects. The VATT/Columbia survey of M31 finds a similar lens fraction
in the M31 dark halo. We propose a series of observations with ACS
that will provide the most thorough search for microlensing toward
M87, the central elliptical galaxy of the Virgo cluster. This program
is optimized for lenses in the mass range from 0.01 to 1.0 solar
masses. By comparing with archival data, we can detect lenses as
massive as 100 solar masses, such as the remnants of the first stars.
These observations will have at least 15 times more sensitivity to
microlensing than any previous survey, e.g. using WFPC2. This is due
to the factor of 2 larger area, factor of more than 4 more sensitivity
in the I-band, superior pixel scale and longer baseline of
observations. Based on the halo microlensing results in the Milky Way
and M31, we might expect that galaxy collisions and stripping would
populate the overall cluster halo with a large number of stellar mass
objects. This program would determine definitively if such objects
compose the cluster dark matter at the level seen in the Milky Way. A
negative result would indicate that such objects do not populate the
intracluster medium, and may indicate that galaxy harassment is not as
vigorous as expected. We can measure the level of events due to the
M87 halo: this would be the best exploration to date of such a lens
population in an elliptical galaxy. Star-star lensing should also be
detectable. About 20 erupting classical novae will be seen, allowing
to determine the definitive nova rate for this giant elliptical
galaxy. We will determine if our recent HST detection of an M87
globular cluster nova was a fluke, or indicative of a 100x higher rate
of incidence of cataclysmic variables and nova eruptions in globulars
than previously believed. We will examine the populations of variable
stars, and will be able to cleanly separate them from microlensing.

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 10520

Resolving the Complex Star Formation History of the Leo I Dwarf
Spheroidal Galaxy

Determining the star formation histories {SFHs} and chemical evolution
of nearby galaxies gives us powerful constrains on the physical
processes that regulate galaxy evolution. The SFHs can be measured
most accurately by comparing the observed densities of stars in
color-magnitude diagrams {CMDs} to predictions from stellar
evolutionary models. WFPC2 imaging of the Leo I dSph shows it is
unique because its stellar population is relatively young.
Approximately 68% of its stars formed between 1 and 7 Gyr ago and only
12% of its stars formed ~ 10 Gyr ago. We propose to vastly improve
the derived SFH of Leo I by exploiting ACS/WFC's higher quantum
efficiency at bluer wavelengths, higher spatial resolution, and larger
field-of-view. The figure of merit for our proposed observations,
defined as the age resolution times the number of stars detected, will
be a factor of 12 higher than existing WFPC2 observations. To surmount
the degeneracy of age and metallicity in the CMD, we have
independently measured the metallicity distribution of its stars using
spectroscopy. Simultaneously modeling the metallicity distribution and
CMD, we will firmly constrain the evolution of the Leo I dSph, a
unique example of an isolated dwarf galaxy that has not been
influenced by interactions with the Milky Way or M31.

FGS 10480

Parallaxes of Extreme Halo Subgiants: Calibrating Globular Cluster
Distances and the Ages of the Oldest

The ages of the oldest stars are a key constraint on the evolution of
our Galaxy, the history of star formation, and cosmological models.
These ages are usually determined from globular clusters. However, it
is alternatively possible to determine ages of extreme Population II
subgiants in the solar neighborhood based on trigonometric parallaxes,
without any recourse to clusters. This approach completely avoids the
vexing issues of cluster distances, reddenings, and chemical
compositions. There are 3 known nearby, extremely metal-deficient Pop
II subgiants with Hipparcos parallax errors of 6-11% which are
available for such age determinations. At present, based on the latest
isochrones, the derived ages of these stars {HD 84937, HD 132475, and
HD 140283} are all close to 14 Gyr, uncomfortably close to or higher
than current estimates of the age of the universe. However, the errors
in the Hipparcos parallaxes imply uncertainties of at least 2 Gyr in
the ages of the 3 stars. We propose to measure parallaxes of these
three Pop II subgiants using HST's Fine Guidance Sensor 1R. We expect
to reduce the Hipparcos parallax error bars by factors of 5-6,
providing the most stringent test yet of current theoretical stellar
models of Pop II stars and pushing the age uncertainties to below 0.5
Gyr. These data will also provide a major new constraint on the
distance scale of globular clusters, with wide implications for
stellar evolution and the calibration of Pop II standard candles. The
ages of the oldest stars are a key constraint on the evolution of our
Galaxy, the history of star formation, and cosmological models. These
ages are usually determined from globular clusters. However, it is
alternatively possible to determine ages of extreme Population II
subgiants in the solar neighborhood based on trigonometric parallaxes,
without any recourse to clusters. This approach completely avoids the
vexing issues of cluster distances, reddenings, and chemical
compositions. There are 3 known nearby, extremely metal- deficient Pop
II subgiants with Hipparcos parallax errors of 6-11% which are
available for such age determinations. At present, based on the latest
isochrones, the derived ages of these stars {HD 84937, HD 132475, and
HD 140283} are all close to 14 Gyr, uncomfortably close to or higher
than current estimates of the age of the universe. However, the errors
in the Hipparcos parallaxes imply uncertainties of at least 2 Gyr in
the ages of the 3 stars. We propose to measure parallaxes of these
three Pop II subgiants using HST's Fine Guidance Sensor 1R. We expect
to reduce the Hipparcos parallax error bars by factors of 5-6,
providing the most stringent test yet of current theoretical stellar
models of Pop II stars and pushing the age uncertainties to below 0.5
Gyr. These data will also provide a major new constraint on the
distance scale of globular clusters, with wide implications for
stellar evolution and the calibration of Pop II standard candles.

FGS 10103

FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of
Upsilon Andromedae d

We propose observations with HST/FGS to determine the astrometric
elements {perturbation orbit semimajor axis and inclination} produced
by the outermost extra-solar planet orbiting the F8V star Upsilon
Andromedae. These observations will permit us to determine the actual
mass of the planet by providing the presently unknown sin i factor
intrinsic to the radial velocity method which discovered this object.
An inclination, i = 30degrees, within the range of one very low
precision determination using reanalyzed HIPPARCOS intermediate data
products, would produce the observed radial velocity amplitude, K = 66
ms with a companion mass of ~8 M_Jupiter. Such a mass would induce in
Upsilon Andromedae a perturbation semi-major axis, Alpha = 0arcs0012,
easily within the reach of HST/FGS fringe tracking astrometry. The
proposed observations will yield a planetary mass, rather than, as
previous investigations have done, only suggest a planetary mass
companion.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10124 - REAcq(1,3,3) not attempted due to LOL during LOS @
041/12:40:00z

REAcq (1,3,3) scheduled @ 041/12:37:45 not attempted due to transition
to M2G during LOS. No flags or ESB's noted. R/T OBAD #1: V1 -165.42,
V2 2266.09, V3 -965.86, RSS 2468.89 R/T OBAD #2: V1 -3.24, V2 -5.94,
V3 2.52, RSS 7.22 Following REAcq (1,3,3) @ 041/14:13:40 was
successful

10125 - GSAcq(1,2,2) failed to (T2G) due to search radius limit
exceeded on FGS-2 @ 042/16:14:26z

The GSAcq(1,2,2) scheduled at 042/16:14:26 - 16:22:31 failed due to
search radius limit exceeded on FGS-2. 486 ESB "a05" (search radius
limit exceeded) was received at 042/16:20:25. The 2nd OBAD at
042/16:09:56 had attitude correction total (RSS) value of 40.36
arcseconds. The OBAD2 success flag was incremented (from "No
Successes" to "One Success"). However, enough attitude error had been
introduced that the Acq could not succeed.

10126 - Roll (V1) attitude error vector limit violation (QDVEFGS1) at
AOS @ 042/17:47:15z

Following a successful REacq(1,2,2) of 042/17:30:01, the mnemonic
(QDVEFGS1) V1 attitude error vector at AOS flagged out of limit low
-99.387 arcseconds during FGS Sequential attitude update.

COMPLETED OPS REQUEST:
17643-0 - Real-Time OBAD @ 041/1343z
17644-0 - Real-Time OBAD @ 041/1403z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS
GSacq 22 21
042/16:14:26z (HSTAR # 10125)
FGS
REacq 22 20
041/11:08:53z, 041/12:40:00z
(HSTAR
# 10124)
OBAD with Maneuver 64 64

SIGNIFICANT EVENTS: (None)

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