Daily #4000

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4000

PERIOD COVERED: UT November 02,03,04, 2005 (DOY 336,337,338)

OBSERVATIONS SCHEDULED

NICMOS 8791

NICMOS Post-SAA calibration - CR Persistence Part 2

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 10738

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
flats currently in the pipeline and to monitor any changes. Weekly
coronagraphic monitoring is required to assess the changing position
of the spots.

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.

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/WFC 10629

Are Field OB Stars Alone?

This SNAP program offers an inexpensive, simple program to search for
low-mass companions of field OB stars. Do field OB stars exist in true
isolation, as suggested by a recent Galactic study, or are they the
tip of the iceberg on a small cluster of low-mass stars as predicted
by the cluster mass function and stellar IMF? Short ACS/WFC V and I
observations proposed here may easily resolve this issue for field OB
stars in the Small Magellanic Cloud. Truly isolated OB stars represent
a theoretical challenge and variation from clusters, in mode of star
formation, and have important consequences for our understanding of
the field stellar population in galaxies. Small clusters around the
field OB stars, on the other hand, may confirm the universality of the
stellar clustering law and IMF.

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/HRC 10609

Sizes, Shapes, and SEDs: Searching for Mass Segregation in the Super
Star Clusters of Nearby Starburst

We propose to investigate mass segregation and star cluster evolution
and dissolution processes in Super Star Cluster {SSC} populations in a
small sample of nearby starburst galaxies. ACS/HRC and NICMOS images
of these nearby {d 10 Mpc} starbursts can reveal evidence for mass
segregation in the form of variations in size, shape, and color of the
SSCs as a function of wavelength. The compactness of the cluster light
profiles, and hence the stellar mass distributions, is a critical
indicator of the likely fate of an SSC: long life and eventual
evolution into a globular-like cluster, or dissolution. These
observations will allow us to generate spectral energy distributions
{SEDs} for a large sample of the SSCs at all ages and extinctions in
each system. We will combine the SEDs with population synthesis models
and existing ground- based spectra and Spitzer images to estimate
ages, reddenings, and masses thus derive a more complete picture of
the star-formation histories of the galaxies. For the brightest and
most likely virialized among the SSCs we will also constrain their
initial mass functions {IMFs} using high- resolution spectroscopy.
Conclusions about IMFs from this technique require detailed
information about the SSC concentration, light profiles, and virial
status, which are only possible via ACS data. The proposed
observations will provide an extensive and comprehensive data set for
a large number of SSCs. By addressing the issues of mass segregation,
evaporation, and destruction of SSC populations, the proposed
observations will provide strong constraints on theories regarding the
processes involved in the formation and evolution of SSCs and globular
clusters. Given the dire predictions for the lifetime of HST, and its
tremendous impact on the study of SSCs, we feel that the proposed
observations not only are necessary and timely {even urgent} but will
also be a fitting { and possibly final} addition to HST's legacy in
the study of starburst SSCs.

ACS/WFC 10600

Studying the spectum of PSR B0656+14

PSR B0656+14 is the brightest intermediate-age pulsar which has been
extensively studied in X- rays and optical with different instruments.
The wide-band photometry of PSR B0656+14 strongly suggests the
presence of spectral features between 4000 and 11, 000 A. The
sensitivity and resolution of ACS/WFC opens an opportunity to study
the pulsar spectrum with a higher resolution and a better S/N than it
was previously possible. This will allow us to accurately measure the
pulsar spectrum, confirm the spectral features and investigate their
shape and strength.

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 and impossible to do without HST}, 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 10586

The Rosetta Stone without a Distance: Hunting for Cepheids in the
Primordial Galaxy I Zw 18

The Blue Compact Dwarf galaxy I Zw 18 is one of the most intriguing
objects in the Local Universe. It has the lowest nebular metallicity
of all known galaxies {Z=1/32 solar}. It has long been regarded as a
possible example of a galaxy undergoing its first burst of star
formation. However, its real evolutionary state continues to be
controversial. The WFPC2 and NICMOS detection of AGB stars by our
group and others suggested the presence of an underlying older
population. However, deeper ACS observations by Izotov & Thuan {2004}
recently failed to detect the signature of RGB stars. This was
interpreted as confirmation that I Zw 18 is in fact a galaxy "in
formation", a local analog of primordial galaxies in the distant
Universe. This result was widely reported in the international news
media. However, an alternative possibility is that I Zw 18 is somewhat
further away than previously believed, so that Red Giant Branch stars
were too faint to detect. Quoted distances in the literature have
ranged from 10 to 20 Mpc. We intend to resolve this controversy by
direct determination of the distance to 1 Mpc accuracy using Cepheids.
For this we request 12 visits of two orbits each, to execute at
carefully planned intervals. We will obtain V and I band ACS/WFC
photometry in each visit. The new data will be combined with archival
data, but we show that the archival data by themselves are
insufficient to achieve our science goals. The distance will allow us
to place I Zw 18 into its proper place in the evolutionary sequence of
galaxy formation.

ACS/HRC 10564

Resolving Ultracool White Dwarf Binaries

We propose an ACS/HRC imaging survey of the coolest white dwarfs known
in order to search for binarity. Current models fail to match observed
spectral energy distributions of these sub- 4000K stellar remnants,
consistently predicting much lower luminosities than observed. A
possible explanation is that they are binary in nature. Because these
cool degenerates have no spectral features, the only way to
investigate their apparent overluminosity is with very high resolution
imaging, which can only be done with HST {these stars are far too
faint to be observed with adaptive optics on the ground}. Optical
wavelengths are ideal because the spectral energy distributions of
these old degenerates peak near 600 nm. With the F435W filter we will
be able to partially resolve equally luminous binaries as close as
0.02", which corresponds to within 0.6 AU for over half of the 12
proposed target stars. The collected data will be critical in
determining whether these stars represent the oldest white dwarfs in
the solar neighborhood.

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.

NIC3 10538

Near-IR Spectrophotometry of 2MASSWJ 1207334-393254B - An Extra-Solar
Planetary Mass Companion

We propose to obtain "short" wavelength near-IR diagnostic and
characterizing spectra of the very high probability candidate
extra-solar giant planet {EGP} companion to 2MASSWJ 1207334- 393254
{2M1207}, a young brown dwarf and TW Hydrae Association member. Recent
NICMOS camera 1 multi-band photometric imaging of the companion
candidate, 0.77" {54 AU projected} from 2M1207 - initially detected at
longer wavelengths with VLT/NACO - implicate an object of several
Jupiter masses based on cooling models of EGPs and the likely age of
2M1207 {~ 8 Myr}. Physical companionship of the EGP candidate with
2M1207 has been established at the 99.1% level of confidence via
second-epoch NICMOS astrometric observations. Diagnostic spectra in
the 0.8 to 1.9 micron region {unobtainable from the ground and
overlapping the NICMOS imaging observations} will {a} critically
inform on the physical nature of the EGP, {b} provide currently
non-existing information to test/constrain theoretical models of EGP
properties and evolution, and {c} unequivocally confirm the imaging of
a bone fide EGP. Background light from 2M1207 would normally swamp the
EGP spectrum with direct spectral imaging. To obviate this, we propose
PSF-subtracted grism spectra of the EGP using 2M1207 as its own
spectral template via two- orientation high-contrast image
subtraction. The temporal stability of the HST+NICMOS PSF enables
self-subtractions of targets at different field orientations resulting
in contrast enhancements of 5 to 6 stellar magnitudes in the
circumstellar background at ~ 0.8" at these wavelengths. With the
grism field oriented to place the EGP "above" and "below" 2M1207 {at
two observational epochs} two independent spectra of the EGP will
emerge from a difference image. This prototypical spectrum will serve
to test and improve upon current models of young EGPs which predict
flux suppression by molecular absorption in their atmospheres.


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/HRC 10525

Characterizing the Near-UV Environment of M Dwarfs: Implications for
Extrasolar Planetary Searches and Astrobiology

We propose SNAP observations with the ACS HRC PR200L prism, designed
to measure the near ultraviolet emission in a sample of 107 nearby M
dwarfs. The sample spans the mass range from 0.1 - 0.6 solar masses
{temperature range 2200K - 4000K} where the UV energy distributions
vary widely between active and inactive stars. The strength and
distribution of this UV emission can have critical consequences for
the atmospheres of attendant planets. Our proposed observations will
provide desperately needed constraints on models of the habitability
zone and the atmospheres of possible terrestrial planets orbiting M
dwarf hosts, and will be used to sharpen TPF target selection. In
addition, the NUV data will be used in conjunction with existing
optical, FUV and X-ray data to constrain a new generation of M dwarf
atmospheric models, and to explore unanswered questions regarding the
dynamo generation and magnetic heating in these low-mass stars.

NIC2 10513

The very late phases of a thermonuclear supernova

A better understanding of the physics of Type Ia supernovae {SNe} is
important for their use as cosmological standard candles. Late time
observations of the SN light curves are poorly studied - but offers a
unique way to probe the explosion models. Combining state of the art
models of 3- D explosions with sophisticated spectral modeling, we can
test these models against observations in a way not earlier possible.
In particular, the broad band light curves are sensitive to the degree
of clumping and the timing of the `infra-red catastrophe', factors
which depend on the explosion mechanism {deflagration vs. delayed
detonation}. Further, these observations can probe the degree of
positron trapping in the ejecta, important for both the SN ejecta and
for the production of free positrons in the galaxy. Because of its
small distance, favorable galaxy location and excellent ground based
follow-up - SN 2003hv offers a unique opportunity to obtain the best
late light curves to date. Observations in several optical and IR
bands will enable us to distinguish between different model
predictions.

ACS/WFC 10497

Cepheid Calibrations of the Luminosity of Two Reliable Type Ia
Supernovae and a Re- determination of the Hubble Constant

We propose to determine the luminosity of two type Ia supernovae {SNe
Ia}, 1995al in NGC 3021 and SN 2002fk in NGC 1309, by observing
Cepheids in their spiral hosts. Modern CCD photometry yields an
extremely tight Hubble diagram for SNe Ia with a precisely determined
intercept {i.e., Delta H_0/H_0}. Yet, the measurement of the true
Hubble constant via SNe Ia is limited by the calibration derived from
problematic and unreliable SN data. Most of the SNe Ia calibrated by
HST to date are significantly compromised by the systematics of
photographic photometry, high reddening and SN peculiarity, and by the
photometric anomolies associated with WFPC2. The extended reach of ACS
now provides opportunities to more reliably calibrate SNe Ia and H_0.
Our Cepheid calibration of a reliable SN Ia dataset, SN 1994ae, using
ACS in Cycle 11 resulted in a 15% increase in H_0 from the value
derived by the HST SN Ia Calibration Program. Yet, there remains a
terribly small sample of reliable SN Ia data sets on which to base
such a crucial cosmological result. SN 1995al and SN 2002fk are two of
the best observed SNe Ia both with little reddening. They provide two
opportunities to use ACS for placing the calibration of H_0 via SN Ia
on firmer footing and potentially improve its precision.

ACS/WFC 10496

Decelerating and Dustfree: Efficient Dark Energy Studies with
Supernovae and Clusters

We propose a novel HST approach to obtain a dramatically more useful
"dust free" Type Ia supernovae {SNe Ia} dataset than available with
the previous GOODS searches. Moreover, this approach provides a
strikingly more efficient search-and-follow-up that is primarily pre-
scheduled. The resulting dark energy measurements do not share the
major systematic uncertainty at these redshifts, that of the
extinction correction with a prior. By targeting massive galaxy
clusters at z 1 we obtain a five-times higher efficiency in
detection of Type Ia supernovae in ellipticals, providing a
well-understood host galaxy environment. These same deep cluster
images then also yield fundamental calibrations required for future
weak lensing and Sunyaev-Zel'dovich measurements of dark energy, as
well as an entire program of cluster studies. The data will make
possible a factor of two improvement on supernova constraints on dark
energy time variation, and much larger improvement in systematic
uncertainty. They will provide both a cluster dataset and a SN Ia
dataset that will be a longstanding scientific resource.

FGS 10477

The Masses of the O-type Binary 15 Monocerotis

The O-type star 15 Mon {HD 47839} was recently discovered to be an
astrometric and spectroscopic binary with a period of 25 years; it is
the first known O-star system to bridge the observational gap between
the period regimes normally probed by these techniques. An analysis of
both the radial velocity curve and astrometric orbit yields the masses
of the components and distance to the system. Continuing radial
velocity and HST/FGS astrometric measurements will lead to a
definitive orbit and yield key information about the masses of O-type
stars. FGS TRANS mode measurements of separation, position angle, and
magnitude difference {begun in Cycle 5} are needed to link existing
speckle observations and anticipated observations with the CHARA Array
optical interferometer. In addition, field astrometry measurements
{FGS POS mode} will provide the proper motion, parallax, and the
binary motion around the center of mass. The POS data will provide an
accurate estimate of the mass ratio and an improved estimate of
distance, and taken together with the spectroscopic and astrometric
orbital data, we will obtain masses for both components accurate to a
few percent.

NIC2/NIC1/NIC3/S/C 10465

NICMOS Autoreset Test

Test of the short term temperature ripples in the NICMOS dewar. The
test consists of running the NICMOS detectors with and without the
AUTORESET mode on. Orbits free of NICMOS science observations are to
be used and each mode {ON/OFF} will run for approximately 24 hours.
The long duration is on order to allow the temperature in the dewar to
stabilize. Normal telemetry data will be sufficient for the
temperature monitoring.

NIC2 10418

Morphologies and Color Gradients of Galaxies with the Oldest Stellar
Populations at High Redshifts

We have isolated a sample of 9 luminous {~2L*} galaxies with the very
oldest stellar populations at their respective redshifts. The galaxies
have been found in radio-source fields chosen to be at the key
redshifts z~1.5 and z~2.5, which allow the cleanest separation of old
stellar populations from highly reddened starbursts with colors
derived from standard filter combinations. Ground-based observations
in excellent seeing and with adaptive optics of 3 of these galaxies
indicate that all 3 are dominated by well relaxed disks of old stars,
suggesting that the first large stellar systems to form in the
universe were disks in which star formation proceeded extremely
rapidly and efficiently. In order to test this conjecture, we are
requesting NICMOS2 exposures of our sample to obtain high S/N imaging
in the F160W filter to determine detailed morphologies of the old
stellar population, coupled with either NICMOS2 F110W or ACS F814W
exposures {depending on redshift} to determine color gradients and/or
other systematic color variations that might provide clues to
formation processes.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10031 - GSAcq (1,2,1) failed due to search radius limit exceeded on
FGS 1 @338/1011z GSAcq (1,2,1) shceduled @ 338/10:10:51 failed due to
search radius limit exceeded. Received ESB "a05" exceeded_SRL. OBAD1
showed the following errors: V1 -5736.02, V2 3370.38, V3 -2785.84, RSS
7212.64 OBAD2 showed the following errors: V1 -3.47, V2 11.85, V3
-3.71, RSS 12.90 OBAD MAP showed the following errors: V1 2.88, V2
64.55, V3 14.68, RSS 66.26

10032 - TREAcq (1,2,1) failed due to search radius limit exceeded on
FGS 1 @338/1146z GSAcq (1,2,1) shceduled @ 338/10:10:51 failed due to
search radius limit exceeded. Received ESB "a05" exceeded_SRL. OBAD1
showed the following errors: V1 -5736.02, V2 3370.38, V3 -2785.84, RSS
7212.64 OBAD2 showed the following errors: V1 -3.47, V2 11.85, V3
-3.71, RSS 12.90 OBAD MAP showed the following errors: V1 2.88, V2
64.55, V3 14.68, RSS 66.26

10033 - Gsacq(2,1,2) failes due to search radius limit exceeded on
FGS2 @339/0439z GSacq(2,1,2) scheduled at 339/04:39:11 failed during a
zoe. At AOS 05:01:30 flags were set indicating search radius limit
exceeded on FGS 2. A ESB "a05" exceeded_SRL was also received. OBAD1
showed errors of V1= 271.39 V2= 885.13 V3= 138.91 RSS= 936.17. OBAD2
had errors of V1= -3.28 V2= -8.61 V3= 3.93 RSS= 10.02

COMPLETED OPS REQUEST:
17604-0 - Real Time OBAD Execution @338/1258z

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS
GSacq 30 28
338/1011z(HSTAR#10031)
339/0439z(HSTAR#10033)

FGS
REacq 08 06
338/1016z//338/1146z (HSTAR#10032)
OBAD with Maneuver 70 70

SIGNIFICANT EVENTS: (None)