Daily Report #4647

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4647

PERIOD COVERED: 5am July 7 - 5am July 8, 2008 (DOY
189/0900z-190/0900z)

OBSERVATIONS SCHEDULED

ACS/SBC 11215

New Sightlines for the Study of Intergalactic Helium: Dozens of
High-Confidence, UV-Bright Quasars from SDSS/GALEX

The reionization of IGM helium is thought to have occurred at
redshifts of z=3 to 4. Detailed study of HeII Lyman-alpha absorption
toward a handful of QSOs at 2.7z3.3 demonstrated the high potential
of such IGM probes, but the critically small sample size limits
confidence in cosmological inferences. The requisite unobscured
sightlines to high-z are extremely rare, but SDSS provides 5800, z3.1
QSOs potentially suitable for HeII studies. We've cross-correlated
SDSS quasars with GALEX UV sources to obtain dozens of new, high
confidence, candidate sightlines {z=3.1-4.9} potentially useful for
detailed HeII studies with HST. We propose brief, 2- orbit
reconnaissance ACS SBC prism exposures toward each of the best dozen
new quasars, to definitively verify UV flux down to HeII. Our combined
SDSS/GALEX selection insures a high confirmation rate, as the quasars
are already known to be UV bright in GALEX. Our program will provide a
statistical sample of HeII sightlines extending to high redshift,
enabling future long exposure follow-up spectra with the SBC prism, or
superb quality COS or STIS spectra after SM4. Stacks of our prism
spectra will also directly yield ensemble information. Ultimately, the
new sightlines will enable confident measures of the spectrum and
evolution of the ionizing background, the evolution of HeII opacity,
the epoch of helium reionization, and the density of IGM baryons.

WFPC2 11024

WFPC2 CYCLE 15 INTERNAL MONITOR

This calibration proposal is the Cycle 15 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
{both gain 7 and gain 15 -- to test stability of gains and bias
levels}, a test for quantum efficiency in the CCDs, and a monitor for
possible buildup of contaminants on the CCD windows. These also
provide raw data for generating annual super-bias reference files for
the calibration pipeline.

FGS 11213

Distances to Eclipsing M Dwarf Binaries

We propose HST FGS observations to measure accurate distances of 5
nearby M dwarf eclipsing binary systems, from which model-independent
luminosities can be calculated. These objects have either poor or no
existing parallax measurements. FGS parallax determinations for these
systems, with their existing dynamic masses determined to better than
0.5%, would serve as model-independent anchor points for the low-mass
end of the mass-luminosity diagram.

NIC1/NIC2/NIC3 11330

NICMOS Cycle 16 Extended Dark

This takes a series of Darks in parallel to other instruments.

NIC1/NIC2/NIC3 8795

NICMOS Post-SAA Calibration - CR Persistence Part 6

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.

NIC3 11107

Imaging of Local Lyman Break Galaxy Analogs: New Clues to Galaxy
Formation in the Early Universe

We have used the ultraviolet all-sky imaging survey currently being
conducted by the Galaxy Evolution Explorer {GALEX} to identify for the
first time a rare population of low-redshift starbursts with
properties remarkably similar to high-redshift Lyman Break Galaxies
{LBGs}. These "compact UV luminous galaxies" {UVLGs} resemble LBGs in
terms of size, SFR, surface brightness, mass, metallicity, kinematics,
dust, and color. The UVLG sample offers the unique opportunity of
investigating some very important properties of LBGs that have
remained virtually inaccessible at high redshift: their morphology and
the mechanism that drives their star formation. Therefore, in Cycle 15
we have imaged 7 UVLGs using ACS in order to 1} characterize their
morphology and look for signs of interactions and mergers, and 2}
probe their star formation histories over a variety of timescales. The
images show a striking trend of small-scale mergers turning large
amounts of gas into vigorous starbursts {a process referred to as
dissipational or "wet" merging}. Here, we propose to complete our
sample of 31 LBG analogs using the ACS/SBC F150LP {FUV} and WFPC2
F606W {R} filters in order to create a statistical sample to study the
mechanism that triggers star formation in UVLGs and its implications
for the nature of LBGs. Specifically, we will 1} study the trend
between galaxy merging and SFR in UVLGs, 2} artificially redshift the
FUV images to z=1-4 and compare morphologies with those in similarly
sized samples of LBGs at the same rest-frame wavelengths in e.g.
GOODS, UDF, and COSMOS, 3} determine the presence and morphology of
significant stellar mass in "pre-burst" stars, and 4} study their
immediate environment. Together with our Spitzer {IRAC+MIPS}, GALEX,
SDSS and radio data, the HST observations will form a unique union of
data that may for the first time shed light on how the earliest major
episodes of star formation in high redshift galaxies came about. This
proposal was adapted from an ACS HRC+WFC proposal to meet the new
Cycle 16 observing constraints, and can be carried out using the
ACS/SBC and WFPC2 without compromising our original science goals.

WEPC2 11196

An Ultraviolet Survey 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 starbursts and creating/fueling
central AGN. We propose far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W}
UV imaging of a sample of 27 galaxies drawn from the complete IRAS
Revised Bright Galaxy Sample {RBGS} LIRGs sample and known, from our
Cycle 14 B and I-band ACS imaging observations, to have significant
numbers of bright {23 B 21 mag} star clusters in the central 30
arcsec. The HST UV data will be combined with previously obtained HST,
Spitzer, and GALEX images to {i} calculate the ages of the clusters as
function of merger stage, {ii} measure the amount of UV light in
massive star clusters relative to diffuse regions of star formation,
{iii} assess the feasibility of using the UV slope to predict the
far-IR luminosity {and thus the star formation rate} both among and
within IR-luminous galaxies, and {iv} provide a much needed catalog of
rest- frame UV morphologies for comparison with rest-frame UV images
of high-z LIRGs and Lyman Break Galaxies. These observations will
achieve the resolution required to perform both detailed photometry of
compact structures and spatial correlations between UV and redder
wavelengths for a physical interpretation our IRX-Beta results. The
HST UV data, combined with the HST ACS, Spitzer, Chandra, and GALEX
observations of this sample, will result in the most comprehensive
study of luminous starburst galaxies to date.

WFPC2 11070

WFPC2 CYCLE 15 Standard Darks - part II

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.

WFPC2 11103

A Snapshot Survey of The Most Massive Clusters of Galaxies

We propose the continuation of our highly successful SNAPshot survey
of a sample of 125 very X-ray luminous clusters in the redshift range
0.3-0.7. As demonstrated by the 25 snapshots obtained so far in
Cycle14 and Cycle15 these systems frequently exhibit strong
gravitational lensing as well as spectacular examples of violent
galaxy interactions. The proposed observations will provide important
constraints on the cluster mass distributions, the physical nature of
galaxy-galaxy and galaxy-gas interactions in cluster cores, and a set
of optically bright, lensed galaxies for further 8-10m spectroscopy.
All of our primary science goals require only the detection and
characterization of high-surface-brightness features and are thus
achievable even at the reduced sensitivity of WFPC2. Because of their
high redshift and thus compact angular scale our target clusters are
less adversely affected by the smaller field of view of WFPC2 than
more nearby systems. Acknowledging the broad community interest in
this sample we waive our data rights for these observations. Due to a
clerical error at STScI our approved Cycle15 SNAP program was barred
from execution for 3 months and only 6 observations have been
performed to date - reinstating this SNAP at Cycle16 priority is of
paramount importance to reach meaningful statistics.

WFPC2 11202

The Structure of Early-type Galaxies: 0.1-100 Effective Radii

The structure, formation and evolution of early-type galaxies is still
largely an open problem in cosmology: how does the Universe evolve
from large linear scales dominated by dark matter to the highly
non-linear scales of galaxies, where baryons and dark matter both play
important, interacting, roles? To understand the complex physical
processes involved in their formation scenario, and why they have the
tight scaling relations that we observe today {e.g. the Fundamental
Plane}, it is critically important not only to understand their
stellar structure, but also their dark-matter distribution from the
smallest to the largest scales. Over the last three years the SLACS
collaboration has developed a toolbox to tackle these issues in a
unique and encompassing way by combining new non-parametric strong
lensing techniques, stellar dynamics, and most recently weak
gravitational lensing, with high-quality Hubble Space Telescope
imaging and VLT/Keck spectroscopic data of early-type lens systems.
This allows us to break degeneracies that are inherent to each of
these techniques separately and probe the mass structure of early-type
galaxies from 0.1 to 100 effective radii. The large dynamic range to
which lensing is sensitive allows us both to probe the clumpy
substructure of these galaxies, as well as their low-density outer
haloes. These methods have convincingly been demonstrated, by our
team, using smaller pilot-samples of SLACS lens systems with HST data.
In this proposal, we request observing time with WFPC2 and NICMOS to
observe 53 strong lens systems from SLACS, to obtain complete
multi-color imaging for each system. This would bring the total number
of SLACS lens systems to 87 with completed HST imaging and effectively
doubles the known number of galaxy-scale strong lenses. The deep HST
images enable us to fully exploit our new techniques, beat down
low-number statistics, and probe the structure and evolution of
early-type galaxies, not only with a uniform data-set an order of
magnitude larger than what is available now, but also with a fully
coherent and self-consistent methodological approach!

WFPC2 11206

At the Cradle of the Milky Way: Formation of the Most Massive Field
Disk Galaxies at z1

We propose to obtain 2 orbit WFPC2 F814W images of a sample of the 15
most massive galaxies found at $1 z 1.3$. These were culled from
over 20,000 Keck spectra collected as part of DEEP and are unique
among high redshift massive galaxy samples in being kinematically
selected. Through a recent HST NICMOS-2 imaging program {GO-10532}, we
have confirmed that these galaxies have regular stellar disks, and
their emission line kinematics are not due to gradients from merging
components. These potentially very young galaxies are likely
precursors to massive local disks, assuming no further merging. The
proposed WFPC2 and existing NIC-2 data provide colors, stellar masses,
and ages of bulge and disk subcomponents, to assess whether old
stellar bulges and disks are in place at that time or still being
built, and constrain their formation epochs. Finally, this sample will
yield the first statistically significant results on the $z 1$
evolution of the size-velocity-luminosity scaling relations, for
massive galaxies at different wavelengths, and constrain whether this
evolution reflects stellar mass growth, or passive evolution, of
either bulge or disk components.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#11377 GSAcq(1,2,1) failed to RGA Hold (Gyro Control) @189/10:12z.

Upon acquisition of signal at 189/11:12:01z, GSAcq(1,2,1) scheduled at
189/10:06:33 - 10:14:38z was observed to have failed to RGA Hold due
to search radius limit exceeded on FGS-1. ESB Dump (ROP DF-18A) at
189/11:16:06z revealed one 486 ESB message "a05" (FGS Coarse Track
failed - Search Radius Limit Exceeded) was received at 189/10:12:23z.
Pre-acquisition OBADs had (RSS) attitude error correction values of
3635.30 and 110.00 arcseconds. Post-acq OBAD/MAP (without maneuver)
had 3-axis error (RSS) value of 1228.25 arcseconds. Subsequent REAcq
(1,2,1) at 189/11:41:07z was successful. Possible Observations
affected: WFPC 23 thru 26, Proposal #ID11196.

#11379 Gyro 6 Motor Current Spike @ 186/18:54z.

At 2008/186/18:54:23z, while in LOS, the Gyro 6 motor current rose to
a maximum value of 313 milliamps, before recovering back to its
pre-transient value of 184 milliamps at 18:55:05z. The final G6 motor
current settled ~1 count below the pre-anomaly level. The gyro 6 bad
disparity counter was seen to increment to 191 counts (4.775 seconds)
(12 second telemetry update rate). The safing test limit is 25
seconds. Gyro 6 experienced its first rotor restriction (HSTAR 11313)
at 2008/141/20:46:18z. This event caused the Loss of Lock documented
in HSTAR 11374.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

******************************* SCHEDULED***** SUCCESSFUL

FGS GSacq********************** 9********************* 8
FGS REacq********************** 4********************* 4
OBAD with Maneuver******* ***** 26******************* 26

SIGNIFICANT EVENTS: (None)

DOY 189 VTFE Curve Adjustment Flash Report

Improvements to the power system configuration have been identified in
the form of a VTFE adjustment.* Recent battery temperature performance
indicates that the system would benefit from a slightly steeper VTFE
slope without a 'Dog Leg'.

At 189/1415 GMT, during an orbit night pass while OCA was not in
progress, the VTFE curves for the batteries were adjusted.* Batteries
1, 2, 4-6 were set at K1L4-100mV with a slope of 80mV/degC and Battery
3 was set at K1L4-50mV, also with a slope of 80mV/degC. Battery 3 is
offset by 50mV due to a calibration tolerance.