Daily Report #4592

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4592

PERIOD COVERED: UT April 17, 2008 (DOY 108)

OBSERVATIONS SCHEDULED

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.

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.

NIC2/WFPC2 11142

Revealing the Physical Nature of Infrared Luminous Galaxies at 0.3z2.7
Using HST and Spitzer

We aim to determine physical properties of IR luminous galaxies at
0.3z2.7 by requesting coordinated HST/NIC2 and MIPS 70um observations
of a unique, 24um flux-limited sample with complete Spitzer mid-IR
spectroscopy. The 150 sources investigated in this program have S{24um}
0.8mJy and their mid-IR spectra have already provided the majority
targets with spectroscopic redshifts {0.3z2.7}. The proposed 150~orbits of
NIC2 and 66~hours of MIPS 70um will provide the physical measurements of the
light distribution at the rest-frame ~8000A and better estimates of the
bolometric luminosity. Combining these parameters together with the rich
suite of spectral diagnostics from the mid-IR spectra, we will {1} measure
how common mergers are among LIRGs and ULIRGs at 0.3z2.7, and establish if
major mergers are the drivers of z1 ULIRGs, as in the local Universe. {2}
study the co-evolution of star formation and blackhole accretion by
investigating the relations between the fraction of starburst/AGN measured
from mid-IR spectra vs. HST morphologies, L{bol} and z. {3} obtain the
current best estimates of the far-IR emission, thus L{bol} for this sample,
and establish if the relative contribution of mid-to-far IR dust emission is
correlated with morphology {resolved vs. unresolved}.

NIC3 11120

A Paschen-Alpha Study of Massive Stars and the ISM in the Galactic Center

The Galactic center (GC) is a unique site for a detailed study of a
multitude of complex astrophysical phenomena, which may be common to nuclear
regions of many galaxies. Observable at resolutions unapproachable in other
galaxies, the GC provides an unparalleled opportunity to improve our
understanding of the interrelationships of massive stars, young stellar
clusters, warm and hot ionized gases, molecular clouds, large scale magnetic
fields, and black holes. We propose the first large-scale hydrogen Paschen
alpha line survey of the GC using NICMOS on the Hubble Space Telescope. This
survey will lead to a high resolution and high sensitivity map of the
Paschen alpha line emission in addition to a map of foreground extinction,
made by comparing Paschen alpha to radio emission. This survey of the inner
75 pc of the Galaxy will provide an unprecedented and complete search for
sites of massive star formation. In particular, we will be able to (1)
uncover the distribution of young massive stars in this region, (2) locate
the surfaces of adjacent molecular clouds, (3) determine important physical
parameters of the ionized gas, (4) identify compact and ultra-compact HII
regions throughout the GC. When combined with existing Chandra and Spitzer
surveys as well as a wealth of other multi-wavelength observations, the
results will allow us to address such questions as where and how massive
stars form, how stellar clusters are disrupted, how massive stars shape and
heat the surrounding medium, and how various phases of this medium are
interspersed.

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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS: (None)

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL

FGS GSacq 12 12
FGS REacq 02 02
OBAD with Maneuver 28 28

SIGNIFICANT EVENTS: (None)