Daily Report #4563

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT****** # 4563

PERIOD COVERED: UT March 07,08,09, 2008 (DOY 067,068,069)

OBSERVATIONS SCHEDULED

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.

WFPC2 11235

HST NICMOS Survey of the Nuclear Regions 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
NICMOS NIC2 imaging of the nuclear regions 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 and resolution of NICMOS NIC2 on HST enables a unique
opportunity to study the detailed structure of the nuclear regions,
where dust obscuration may mask star clusters, AGN and additional
nuclei from optical view, with a resolution significantly higher than
possible with Spitzer IRAC. This survey thus provides a crucial
component to our study of the dynamics and evolution of IR galaxies
presently underway with Wide-Field, HST ACS/WFC and Spitzer IRAC
observations of these 88 galaxies. Imaging will be done with the F160W
filter {H-band} to examine as a function of both luminosity and merger
stage {i} the luminosity and distribution of embedded star clusters,
{ii} the presence of optically obscured AGN and nuclei, {iii} the
correlation between the distribution of 1.6 micron emission and the
mid- IR emission as detected by Spitzer IRAC, {iv} the evidence of
bars or bridges that may funnel fuel into the nuclear region, and {v}
the ages of star clusters for which photometry is available via
ACS/WFC observations. The NICMOS data, combined with the HST ACS,
Spitzer, and GALEX observations of this sample, will result in the
most comprehensive study of merging and interacting galaxies to date.

FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is
seriously incomplete for systems in the period range from years to
millennia because the radial velocity variations are too small and the
angular separations too close for easy detection. Here we propose to
discover binaries in this observational gap through a Faint Guidance
Sensor SNAP survey of relatively bright targets listed in the Galactic
O Star Catalog. Our primary goal is to determine the binary frequency
among those in the cluster/association, field, and runaway groups. The
results will help us assess the role of binaries in massive star
formation and in the processes that lead to the ejection of massive
stars from their natal clusters. The program will also lead to the
identification of new, close binaries that will be targets of long
term spectroscopic and high angular resolution observations to
determine their masses and distances. The results will also be
important for the interpretation of the spectra of suspected and newly
identified binary and multiple systems.

FGS 11211

An Astrometric Calibration of Population II Distance Indicators

In 2002 HST produced a highly precise parallax for RR Lyrae. That
measurement resulted in an absolute magnitude, M{V}= 0.61+/-0.11, a
useful result, judged by the over ten refereed citations each year
since. It is, however, unsatisfactory to have the direct,
parallax-based, distance scale of Population II variables based on a
single star. We propose, therefore, to obtain the parallaxes of four
additional RR Lyrae stars and two Population II Cepheids, or W Vir
stars. The Population II Cepheids lie with the RR Lyrae stars on a
common K-band Period-Luminosity relation. Using these parallaxes to
inform that relationship, we anticipate a zero-point error of 0.04
magnitude. This result should greatly strengthen confidence in the
Population II distance scale and increase our understanding of RR
Lyrae star and Pop II Cepheid astrophysics.

FGS 11210

The Architecture of Exoplanetary Systems

Are all planetary systems coplanar? Concordance cosmogony makes that
prediction. It is, however, a prediction of extrasolar planetary
system architecture as yet untested by direct observation for main
sequence stars other than the Sun. To provide such a test, we propose
to carry out FGS astrometric studies on four stars hosting seven
companions. Our understanding of the planet formation process will
grow as we match not only system architecture, but formed planet mass
and true distance from the primary with host star characteristics for
a wide variety of host stars and exoplanet masses. We propose that a
series of FGS astrometric observations with demonstrated 1 millisecond
of arc per-observation precision can establish the degree of
coplanarity and component true masses for four extrasolar systems: HD
202206 {brown dwarf+planet}; HD 128311 {planet+planet}, HD 160691 = mu
Arae {planet+planet}, and HD 222404AB = gamma Cephei {planet+star}. In
each case the companion is identified as such by assuming that the
minimum mass is the actual mass. For the last target, a known stellar
binary system, the companion orbit is stable only if coplanar with the
AB binary orbit.

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.

WFPC2 11180

The Morphology of the Post-Red Supergiant IRC+10420's Circumstellar
Ejecta

The extremely luminous post-red supergiant and powerful OH/IR source
IRC +10420 is surrounded by a complex circumstellar nebula. Numerous
small condensations, arcs, jet-like rays of knots, and intriguing
semi-circular structures are easily visible in our previous WFPC2
images. We have suggested that these spatially recognizable features
may be evidence for episodic mass loss events possibly from localized
active regions. We now propose to obtain second epoch WFPC2 images
with the Planetary Camera to measure the transverse motions of these
ejecta. Spatially resolved spectra from STIS showed that the embedded
arcs are kinematically distinct from the spherically expanding diffuse
nebulosity. The transverse motions in combination with radial
velocities from the STIS spectra, will let us determine the morphology
of IRC +10420's nebula and the structures embedded in it, its mass
loss history, and provide clues to the mass loss mechanism responsible
for the discrete ejections.

NIC2 11168

The IMF in the Hidden Galactic Starburst W49A

W49A is one of the most luminous and prolific massive star formation
regions in the disk of our Milky Way. Given the presence of several
very massive OB clusters as well as an unusually high concentration of
many young ultra-compact HII regions (UCHIIR) -- all embedded in about
1 million solar masses of molecular gas -- it is arguably the best
Galactic template for a luminous starburst region. We propose to
obtain NICMOS imaging of the central part of W49A, covering a strip
from the central, massive OB cluster to the ring of UCHIIRs. Our goals
are to resolve and characterize the central star cluster and determine
its IMF down to about 1 solar mass. We want to characterize the
distribution of intermediate-mass YSOs, and identify the NIR
counterparts to the UCHIIRs. The combination of the proposed
HST/NICMOS data with our recently obtained Spitzer observations would
allow a great step forward in the understanding of massive star and
cluster formation.

NIC2 11157

NICMOS Imaging Survey of Dusty Debris Around Nearby Stars Across the
Stellar Mass Spectrum

Association of planetary systems with dusty debris disks is now quite
secure, and advances in our understanding of planet formation and
evolution can be achieved by the identification and characterization
of an ensemble of debris disks orbiting a range of central stars with
different masses and ages. Imaging debris disks in starlight scattered
by dust grains remains technically challenging so that only about a
dozen systems have thus far been imaged. A further advance in this
field needs an increased number of imaged debris disks. However, the
technical challenge of such observations, even with the superb
combination of HST and NICMOS, requires the best targets. Recent HST
imaging investigations of debris disks were sample-limited not limited
by the technology used. We performed a search for debris disks from a
IRAS/Hipparcos cross correlation which involved an exhaustive
background contamination check to weed out false excess stars. Out of
~140 identified debris disks, we selected 22 best targets in terms of
dust optical depth and disk angular size. Our target sample represents
the best currently available target set in terms of both disk
brightness and resolvability. For example, our targets have higher
dust optical depth, in general, than newly identified Spitzer disks.
Also, our targets cover a wider range of central star ages and masses
than previous debris disk surveys. This will help us to investigate
planetary system formation and evolution across the stellar mass
spectrum. The technical feasibility of this program in two-gyro mode
guiding has been proven with on-orbit calibration and science
observations during HST cycles 13, 14, and 15.

ACS/SBC 11154

Optical-UV Spectrum of the Middle-aged Pulsar B1055-52

The middle-aged radio, X-ray and gamma-ray pulsar B1055-52 is one of
the few pulsars that allow a multiwavelength study of pulsar
radiation. An optical counterpart of the pulsar has been detected with
the HST FOC, but it was observed in only one filter (F342W, m=24.9).
To understand the nature of the pulsar radiation, its spectrum must be
measured in a broad wavelength range. We propose imaging observations
of the pulsar's counterpart with WFPC2 in the red part of the spectrum
and ACS/SBC in the UV part to measure the broadband spectral
distribution, compare it with the X-ray spectrum, and investigate the
thermal and magnetospheric components of the pulsar's radiation.

WFPC2 11138

The Physics of the Jets of Powerful Radio Galaxies and Quasars

We propose to obtain HST polarimetry of the jets of the quasars
1150+497 and PKS 1136-135. Our goal is to solve the riddle of their
high-energy emission mechanism, and tackle issues such as particle
acceleration and jet dynamics. Our targets are the optically brightest
quasar jets, and they span the range of luminosities and beaming
parameters seen in these objects. Recent observations with Spitzer,
HST and Chandra have shed new light on the spectral morphology of
quasar jets, throwing wide open the question of the nature of their
optical and X-ray emission. Three mechanisms are possible, including
synchrotron emission as well as two Comptonization processes.
Polarimetry can uniquely determine which of these mechanisms operates
in the optical. We will compare the optical polarimetry to in- hand
radio polarimetry as well as in-hand and new Spitzer, HST and Chandra
imaging to gain new insights on the structure of these jets, as well
as particle acceleration mechanisms and jet dynamics.

WFPC2 11124

The Origin of QSO Absorption Lines from QSOs

We propose using WFPC2 to image the fields of 10 redshift z ~ 0.7
foreground {FG} QSOs which lie within ~29-151 kpc of the sightlines to
high-z background {BG} QSOs. A surprisingly high fraction of the BG
QSO spectra show strong MgII {2796,2803} absorption lines at precisely
the same redshifts as the FG QSOs. The high resolution capabilities of
WFPC2 are needed to understand the origin of these absorption systems,
in two ways. First, we wish to explore the FG QSO environment as close
as possible to the position of the BG QSO, to search for interloping
group or cluster galaxies which might be responsible for the
absorption, or irregularly shaped post-merger debris between the FG
and BG QSO which may indicate the presence of large amount of
disrupted gas along a sightline. Similarly, high resolution images are
needed to search for signs of tidal interactions between any galaxies
which might be found close to the FG QSO. Such features might provide
evidence of young merging events causing the start of QSO duty cycles
and producing outflows from the central AGN. Such winds may be
responsible for the observed absorption lines. Second, we seek to
measure the intrinsic parameters of the FG QSO host galaxy, such as
luminosity and morphology, to correlate with the properties of the
MgII absorption lines. We wish to observe each field through the F814W
filter, close to the rest- frame B-band of the FG QSO. These blue data
can reveal enhanced star formation regions close to the nucleus of the
host galaxy, which may be indicative of galaxy mergers with the FG QSO
host. The FG QSO environment offers quite a different set of phenomena
which might be responsible for MgII absorption, providing an important
comparison to studies of MgII absorption from regular field galaxies.

WFPC2 11113

Binaries in the Kuiper Belt: Probes of Solar System Formation and
Evolution

The discovery of binaries in the Kuiper Belt and related small body
populations is powering a revolutionary step forward in the study of
this remote region. Three quarters of the known binaries in the Kuiper
Belt have been discovered with HST, most by our snapshot surveys. The
statistics derived from this work are beginning to yield surprising
and unexpected results. We have found a strong concentration of
binaries among low-inclination Classicals, a possible size cutoff to
binaries among the Centaurs, an apparent preference for nearly equal
mass binaries, and a strong increase in the number of binaries at
small separations. We propose to continue this successful program in
Cycle 16; we expect to discover at least 13 new binary systems,
targeted to subgroups where these discoveries can have the greatest
impact.

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.

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 11029

WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly
Monitor

Intflat observations will be taken to provide a linearity check: the
linearity test consists of a series of intflats in F555W, in each gain
and each shutter. A combination of intflats, visflats, and earthflats
will be used to check the repeatability of filter wheel motions.
{Intflat sequences tied to decons, visits 1-18 in prop 10363, have
been moved to the cycle 15 decon proposal xxxx for easier scheduling.}
Note: long-exposure WFPC2 intflats must be scheduled during ACS
anneals to prevent stray light from the WFPC2 lamps from contaminating
long ACS external exposures.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11214 - NICMOS Detector #2 VSRC Voltage (ND2VSRCV) Limit Violation

The NICMOS Detector #2 VSRC Voltage (ND2VSRCV) flagged OOL high 5.19
volts for one sample starting at 068/21:58:46 and return within its
nominal (~5.1) range about 30 seconds later at 068/21:59:15. Similar
occurrence documented in HSTARs 9586, 9728.

11215 - NICMOS Suspend

At 069/02:46:03 NICMOS Suspended with a status buffer message NICMOS
632, P = 225, T = 34342, indicating "MECH_2_MAX_RETRIES_EXCEEDED". The
number of positioning error retries attempted during a Filter Wheel 2
movement exceeded the maximum limit.

At 069/08:46:45 received Exec 272 status buffer message P=0, T=10871.

At acquisition of signal, 069/09:22:30, an Exec 272 status buffer
message had been received at 069/08:59:01, P=0, T=16759.

COMPLETED OPS REQUEST:

18212-0 - Dump NICMOS Memory Following Suspend @ 069/0511z
18213-0 - NICMOS Suspend Recovery @ 069/1515z

COMPLETED OPS NOTES: (None)

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

FGS GSacq************** 20****************** 20
FGS REacq************** 18***************** 18
OBAD with Maneuver **** 70***************** 70

SIGNIFICANT EVENTS:

Flash Report:

NICMOS suspended on 2008/069/02:46:03 due to filter wheel #2 exceeding
its maximum allotted number of retries (HSTAR# 11215). Data analysis
was performed and the suspend event was attributed to known noise in
the filter wheel #2 electronics.

Flash Report:

NICMOS was successfully recovered and has successfully completed the
first observation set. NICMOS was recovered to operate at 069/13:59
via Ops Request 18213 and the PAMs were moved to the chronographic
position (PAMC) at 069/15:14 to intercept the SMS. The first science
observations were complete at 069/17:06. HST was in a ZOE at the time,
but upon acquisition of data, there were no error messages and NICMOS
was operating as expected.