HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT    #4645

PERIOD COVERED: 5am July 2 - 5am July 3, 2008 (DOY 184/0900z-185/0900z)

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 11136

Resolving Ultracool Astrophysics with Brown Dwarf Binaries

We propose to obtain resolved far-red and near-IR photometry of 13 brown
dwarf binaries with HST/NICMOS in order to study one of the
long-standing puzzles in ultracool astrophysics, namely the rapid change
in spectra from L dwarfs to T dwarfs at nearly constant effective
temperature (a.k.a. the "L/T transition''). While many nearby brown
dwarfs have been studied, use of such samples is inevitably hindered by
the unknown ages, masses, and metallicities of the field population.
Characterization of resolved ultracool binaries is a promising avenue
for addressing this problem, by providing coeval systems of the same
composition with comparable masses and temperatures. Our proposed
HST/NICMOS (0.9-1.6 micron) observations will be combined with longer
wavelength ground-based photometry and spectroscopy from Keck laser
guide star adaptive optics. The resulting multiband (0.9-2.5 micron)
dataset will be a unique resource for measuring the evolution of
spectral energy distributions across the L/T transition, to test
state-of-the-art atmospheric models, and to determine the physical
process(es) that dominate the L/T transition. Understanding the L/T
transition is important not only for testing brown dwarf atmospheres,
but also provides a key pathway for understanding the same physical
effects, namely the formation and removal of clouds, in the atmospheres
of the extrasolar planets.

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 i
mages. Each observation will need its own CRMAP, as different SAA
passages leave different imprints on the NICMOS detectors.

NIC2 11135

Extreme Makeovers: Tracing the Transformation of Massive Galaxies at
z~2.5

To obtain a full spectroscopic census of the universe at z~2.5 we have
conducted a near-infrared spectroscopic survey for K-selected galaxies.
We found that, in contrast to the local universe, massive high-redshift
galaxies span a wide range of properties, varying from (dusty) star
burst to "red and dead" galaxies. This may imply that massive galaxies
transform from star-forming to quiescent galaxies in the targeted
redshift range. To understand whether the 9 quiescent galaxies in our
sample are the progenitors of local elliptical, we are observing them in
the current cycle with NIC2. For cycle 16 we propose to complete our
sample of massive z~2.5 galaxies and image the remaining 10 galaxies,
which all have emission lines. Based on emission-line diagnostics, 6 of
these galaxies are identified as star-forming objects and 4 harbor an
active galactic nucleus. The goals are to 1) determine whether star
formation in massive z~2.5 galaxies takes place in disks or is triggered
by merger activity, 2) derive the contribution of AGNs to the rest-frame
optical emission, and 3) test whether the morphologies are consistent
with the idea that the star-forming galaxies, AGNs, and quiescent
galaxies represent subsequent phases of an evolutionary sequence. The
combination of both programs will provide the first morphological study
of a spectroscopically confirmed massive galaxy sample at z~2.5.

NIC3 11195

Morphologies of the Most Extreme High-Redshift Mid-IR-luminous Galaxies
II: The `Bump' Sources

The formative phase of some of the most massive galaxies may be
extremely luminous, characterized by intense star- and AGN-formation.
Till now, few such galaxies have been unambiguously identified at high
redshift, and thus far we have been restricted to studying the
low-redshift ultraluminous infrared galaxies as possible analogs. We
have recently discovered a sample of objects which may indeed represent
this early phase in galaxy formation, and are undertaking an extensive
multiwavelength study of this population. These objects are optically
extremely faint {R>26} but nevertheless bright at mid-infrared
wavelengths {F[24um] > 0.5 mJy}. Mid-infrared spectroscopy with
Spitzer/IRS reveals that they have redshifts z~2, implying luminosities
~1E13 Lsun. Their mid-IR SEDs fall into two broad, perhaps overlapping,
categories. Sources with brighter F[24um] exhibit power-law SEDs and SiO
absorption features in their mid-IR spectra characteristic of AGN,
whereas those with fainter F[24um] show a "bump" characteristic of the
redshifted 1.6um peak from a stellar population, and PAH emission
characteristic of starformation. We have begun obtaining HST images of
the brighter sources in Cycle 15 to obtain identifications and determine
kpc-scale morphologies for these galaxies. Here, we aim to target the
second class {the "bump" sources} with the goal of determining if these
constitute morphologically different objects, or simply a "low-AGN"
state of the brighter class. The proposed observations will help us
determine whether these objects are merging systems, massive obscured
starbursts {with obscuration on kpc scales!} or very reddened {locally
obscured} AGN hosted by intrinsically low-luminosity galaxies.

WFPC2 11222

Direct Detection and Mapping of Star Forming Regions in Nearby, Luminous
Quasars

We propose to carry out narrow-band emission line imaging observations
of 8 quasars at z=0.05-0.15 with the WFPC2 ramp filters and with the
NICMOS narrow-band filters. We will obtain images in the [O II], [O
III], H-beta, and Pa-alpha emission line bands to carry out a series of
diagnostic tests aimed at detecting and mapping out star-forming regions
in the quasar host galaxies. This direct detection of star-forming
regions will confirm indirect indications for star formation in quasar
host galaxies. It will provide a crucial test for models of quasar and
galaxy evolution, that predict the co-existence of starbursts and
"monsters" and will solve the puzzle of why different indicators of star
formation give contradictory results. A secondary science goal is to
assess suggested correlations between quasar luminosity and the size of
the narrow-line region.

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                      7                    7              
FGS REacq                      7                    7                 
OBAD with Maneuver        22                  22                             

SIGNIFICANT EVENTS: (None)