Daily 3807

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 3807

PERIOD COVERED: DOY 60

OBSERVATIONS SCHEDULED

ACS/HRC 10198

Probing the Dynamics of the Galactic Bar through the Kinematics of
Microlensed Stars

The observed optical depths to microlensing of stars in the Galactic
bulge are difficult to reconcile with our present understanding of
Galactic dynamics. The main source of uncertainty in those comparisons
is now shifting from microlensing measurements to the dynamical models
of the Galactic bar. We propose to constrain the Galactic bar models
with proper motion observations of Bulge stars that underwent
microlensing by determining both the kinematic identity of the
microlensed sources and the importance of streaming motions. The
lensed stars are typically farther than randomly selected stars.
Therefore, our proper motion determinations for 36 targeted MACHO
events will provide valuable constraints on the dynamics of bulge
stars as a function of distance. The first epoch data for our proposed
events is already available in the HST archive so the project can be
completed within a single HST cycle. The exceptional spatial
resolution of HST is essential for completion of the project.
Constraints on the total mass in the bulge will ultimately lead to the
determination of the amount of dark matter in inner Galaxy.

ACS/HRC 10255

A Never Before Explored Phase Space: Resolving Close White Dwarf / Red
Dwarf Binaries

We propose an ACS Snapshot imaging survey to resolve a well-defined
sample of highly probable white dwarf plus red dwarf close binaries.
These candidates were selected from a search for white dwarfs with
infrared excess from the 2MASS database. They represent unresolved
systems {separations less than approximately 2" in the 2MASS images}
and are distributed over the whole sky. Our HST+ACS observations will
be sensitive to a separation range {1-20 AU} never before probed by
any means. The proposed study will be the first empirical test of
binary star parameters in the post-AGB phase, and cannot be
accomplished from the ground. By resolving as few as 20 of our ~100
targets with HST, we will be able to characterize the distribution of
orbital semi- major axes and secondary star masses.

ACS/WFC 10217

The ACS Fornax Cluster Survey

The two rich clusters nearest to the Milky Way, and the only large
collections of early- type galaxies within ~ 25 Mpc, are the Virgo and
Fornax Clusters. We propose to exploit the exceptional imaging
capabilities of the ACS/WFC to carry out the most comprehensive
imaging survey to date of early-type galaxies in Fornax: the ACS
Fornax Cluster Survey. Deep ACS/WFC images -- in the F475W {g'} and
F850LP {z'} bands -- will be acquired for 44 E, S0, dE, dE, N and dS0
cluster members. In Cycle 11, we initiated a similar program targeting
early-type galaxies in the Virgo Cluster {the ACS Virgo Cluster
Survey; GO-9401}. Our proposed survey of Fornax would yield an
extraordinary dataset which would complement that already in hand for
Virgo, and allow a definitive study of the role played by environment
in the structure, formation and evolution of early-type galaxies and
their globular cluster systems, nuclei, stellar populations, dust
content, nuclear morphologies and merger histories. It would also be a
community resource for years to come and, together with the ACS Virgo
Cluster Survey, constitute one of the lasting legacies of HST.

ACS/WFC 10361

Earth Flats

This proposal monitors flatfield stability. This proposal obtains
sequences of Earth streak flats to construct high quality flat fields
for the WFPC2 filter set. These flat fields will allow mapping of the
OTA illumination pattern and will be used in conjunction with previous
internal and external flats to generate new pipeline superflats. These
Earth flats will complement the Earth flat data obtained during cycles
4-12.

NIC1 10143

Ultracool companions to the nearest L dwarfs

We propose to conduct the most sensitive survey to date for low mass
companions to nearby L dwarfs. We will use NICMOS to image targets
drawn from a volume-complete sample of 70 L dwarfs within 20 parsecs.
The combination of infrared imaging and proximity will allow us to
search for T dwarf companions at separations as small as 1.6 AU. This
is crucial, since no ultracool binaries are currently known with
separations exceeding 15 AU. Only 10 dwarfs in this sample have
previous HST observations primarily at optical wavelengths. With the
increased sensitivity of our survey, we will provide the most
stringent test to date of brown dwarf models which envisage formation
as ejected stellar embryos. In addition, our observations will be
capable of detecting binaries with mass ratios as low as 0.3, and will
therefore also test the apparent preference for equal-mass ultracool
binaries. Finally, our observations offer the best prospect to date of
detecting companions significantly cooler than the coolest t dwarf
currently known.

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.

NIC2 10176

Coronagraphic Survey for Giant Planets Around Nearby Young Stars

A systematic imaging search for extra-solar Jovian planets is now
possible thanks to recent progress in identifying "young stars near
Earth". For most of the proposed young {~ 30 Myrs} and nearby {~ 60
pc} targets, we can detect a few Jupiter-mass planets as close as a
few tens of AUs from the primary stars. This represents the first time
that potential analogs of our solar system - that is planetary systems
with giant planets having semi-major axes comparable to those of the
four giant planets of the Solar System - come within the grasp of
existing instrumentation. Our proposed targets have not been observed
for planets with the Hubble Space Telescope previously. Considering
the very successful earlier NICMOS observations of low mass brown
dwarfs and planetary disks among members of the TW Hydrae Association,
a fair fraction of our targets should also turn out to posses low mass
brown dwarfs, giant planets, or dusty planetary disks because our
targets are similar to {or even better than} the TW Hydrae stars in
terms of youth and proximity to Earth. Should HST time be awarded and
planetary mass candidates be found, proper motion follow-up of
candidate planets will be done with ground-based AOs.

NIC3 10385

Spectrophotometry of Solar Analog Stars and NICMOS Grism Calibration

NICMOS IR Standards {4 orbits} In cycle 12, 24 orbits were used to
measure the NICMOS grism mode sensitivities and to establish a set of
IR flux standards with a goal of 1% accuracy. However, the G096
setting shows up to 5% peak-to-peak range among the sensitivities
derived from the three primary WD standards, as shown in Figure 1 {for
the Phase 1 proposal}. The possible causes of this large scatter
include changes in the flat field, a systematic change of sensitivity
with time, and a fundamental limitation of the repeatability for stars
at the WD flux levels. The same residuals for STIS in the 0.8- 1.0
micron overlap range are 1%, so that the problem is not with the
fluxes for the three primary standard stars. Either there is a
systematic trend in the NICMOS grism data that can be removed with
more monitoring; or alternatively, repeating the cycle 12 observations
should reduce the error in the mean sensitivity by sqrt{2}, if the
deviations among the stars are random instrumental fluctuations. The
NICMOS cycle 13 calibration program includes 2 orbits to repeat the
observations of the bright standard BD+17d4708, which has a very high
S/N, so that any change in its response should reflect an instrumental
sensitivity difference between cycle 12 and 13. The four Nicmos orbits
in this program include one each for GD71 and GD153 in G096 and G141,
while two orbits are required for the repeat of G191B2B, where the
G206 mode is also included.

NIC3/WFPC2 10403

Ultraviolet Imaging of the UDF

The Hubble Deep Field North has uninterrupted observations at
wavelengths from Far- UV through NICMOS H-band, but the UDF goes no
bluer than B-band. We propose to complete the UDF coverage with deep
ultraviolet imaging of the Ultra-Deep Field {UDF} with the ACS-SBC in
the Far-UV {1500 Angstrom} and WFPC2 in the Near-UV {F300W}. We will
reach point source limits of ABmag=28.5, a factor of ten fainter than
the GALEX ultradeep surveys. Our dataset will add to the value of the
UDF legacy, and requires the unique capabilities of HST. In the spirit
of the UDF, we submit this proposal in the Treasury category. We
request a modest allocation of observing time for a Treasury program:
62 orbits. We will provide science quality images and photometric
catalogs to enable a range of research topics by the community. The
science goals of the team are to investigate the episode of strong
star formation activity in galaxies out to z=1, through the rest-frame
FUV luminosity function and the internal color structure of galaxies.
Far-UV number counts suggest that moderate redshift {z~0.5} starbursts
are undergoing a single, rapid burst of star-formation. We will
investigate this result by measuring the faint-end slope, alpha, of
the luminosity function. We will measure the star formation properties
of moderate redshift starburst galaxies and compare their morphologies
in the UV, optical, and near-IR. This catalog of starbursts will also
be important to the astronomical community in correlating unobscured
star-formation with the sources detected in the Spitzer Space
Telescope legacy observations of the field. With the high spatial
resolution data, will set strict limits on the flux escaping in
intermediate redshift {1z2} galaxies at wavelengths below the
rest-frame Lyman limit, and thus infer the contribution of star
forming galaxies at z~5 to the metagalactic ionizing radiation.

WFPC2 10360

WFPC2 CYCLE 13 INTERNAL MONITOR

This calibration proposal is the Cycle 13 routine internal monitor for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety of internal exposures are obtained in order to provide a
monitor of the integrity of the CCD camera electronics in both bays
{gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a
monitor for possible buildup of contaminants on the CCD windows.

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary
reports of potential non-nominal performance that will be
investigated.) None

COMPLETED OPS REQs: None


OPS NOTES EXECUTED:
1309-1 Consolidated PCS Limit Modifications @060/2141z

SCHEDULED SUCCESSFUL FAILURE TIMES
FGS Gsacq 14 14
FGS Reacq 07 07
FHST Update 19 19
LOSS of LOCK


SIGNIFICANT EVENTS: None