Daily Rpt #4683

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT*** #4683

PERIOD COVERED: 5am August 26 - 5am August 27, 2008 (DOY
239/0900z-240/0900z)

OBSERVATIONS SCHEDULED

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.

NIC1 11205

The Effects of Multiplicity on the Evolution of Young Stellar Objects:
A NICMOS Imaging Study

We propose to use NICMOS to investigate the multiplicity of young
stellar objects (YSOs) in the Orion B molecular cloud. Previous
observations with the Spitzer Space Telescope have revealed a
remarkable star forming filament near the NGC 2068 reflection nebula.
The population of YSOs associated with the filament exhibit a
surprisingly wide range of circumstellar evolutionary states, from
deeply embedded protostars to T Tauri accretion disks. Many of the
circumstellar disks themselves show evidence for significant dust
evolution, including grain growth and settling and cleared inner
holes, apparently in spite of the very young age of these stars. We
will estimate the binary fraction of a representative sample of
objects in these various stages of evolution in order to test whether
companions may play a significant role in that evolution.

NIC1/NIC2/NIC3 11820

NICMOS Post-SAA Calibration - CR Persistence Part 7

Internals for CR persistence

NIC2 11548

NICMOS Imaging of Protostars in the Orion A Cloud: The Role of
Environment in Star Formation

We propose NICMOS observations of a sample of 252 protostars
identified in the Orion A cloud with the Spitzer Space Telescope.
These observations will image the scattered light escaping the
protostellar envelopes, providing information on the shapes of outflow
cavities, the inclinations of the protostars, and the overall
morphologies of the envelopes. In addition, we ask for Spitzer time to
obtain 55-95 micron spectra of 75 of the protostars. Combining these
new data with existing 3.6 to 70 micron photometry and forthcoming
5-40 micron spectra measured with the Spitzer Space Telescope, we will
determine the physical properties of the protostars such as envelope
density, luminosity, infall rate, and outflow cavity opening angle. By
examining how these properties vary with stellar density (i.e.
clusters vs groups vs isolation) and the properties of the surrounding
molecular cloud; we can directly measure how the surrounding
environment influences protostellar evolution, and consequently, the
formation of stars and planetary systems. Ultimately, this data will
guide the development of a theory of protostellar evolution.

NIC2 11799

NICMOS Non-linearity Calibration for Faint Objects

NICMOS has played a key role in probing the deep near infrared regime
for a decade. It has been the only instrument available to observe
objects in the near infrared that are not visible from the ground. In
particular, it has played a major role in the SN Ia observations at
redshifts z1. However, the calibration of NICMOS has turned out to be
difficult due to the apparent non-linearity of the detectors. The
NICMOS calibration team has described the non-linearity as a power law
based on data in the range of ~50-5000 ADU/s. The correction relies on
an extrapolation of two orders of magnitude in flux at count rates
close to the sky level (0.1 ADU/s) where space observations are
particularly prized - and where SN Ia observations are made. Precise
measurements of faint objects require us to reduce the uncertainties
from this extrapolation. Here we propose to derive the absolute
calibration in the sky limited regime and to characterize the
non-linearity over the entire dynamic range for the camera/filter
combination: NIC2/F110W.

NIC3 11512

Molecules in Exoplanet Atmospheres

We propose to characterize the conditions, composition, and chemistry
in two transiting exoplanet atmospheres using molecules as probes.
This will be accomplished through high precision, near-IR spectroscopy
during an interval that spans the primary and/or secondary eclipse
events. We have selected the hot-Jovian HD 209458b and the
warm-Neptune GJ 436b for spectroscopy from 1.4 to 2.5 microns and we
expect to detect the molecules H2O, CH4, CO, CO2, and NH3. We will
infer the atmospheric temperature-pressure profiles and determine the
abundance of detected molecules; this will be done by comparing
detailed radiative transfer models with emission and transmission
spectra of the exoplanet atmospheres. Taken together with the existing
observations of HD 189733b, the proposed measurements will probe the
diversity of exoplanet atmospheres and the effects of radiation from
the stellar primary.

WFPC2 11119

The Stellar Origins of Supernovae

Supernovae {SNe} have a profound effect on galaxies, and have been
used recently as precise cosmological probes, resulting in the
discovery of the accelerating Universe. They are clearly very
important events deserving of intense study. Yet, even with nearly
4000 known SNe, we know relatively little about the stars which give
rise to these powerful explosions. The main limitation has been the
lack of spatial resolution in pre-SN imaging data. However, since 1999
our team has been at the vanguard of directly identifying SN
progenitor stars in HST images. From this exciting new line of study,
the emerging trend from 5 detections for Type II-Plateau SNe is that
their progenitors appear to be relatively low mass {8 to 20 Msun} red
supergiants, although more cases are needed. Nonetheless, the nature
of the progenitors of Type Ib/c SNe, a subset of which are associated
with the amazing gamma-ray bursts, remains ambiguous. Furthermore, we
remain in the continually embarrassing situation that we still do not
yet know which progenitor systems explode as Type Ia SNe, which are
currently being used for precision cosmology. We propose to confirm
the identities of the progenitors of 4 SNe within 17 Mpc, which we
expect to occur during Cycle 16, through ToO observations using
WFPC2/PC.

WFPC2 11130

AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge
Paradigm, Part II

The recent progress in the study of central black holes in galactic
nuclei has led to a general consensus that supermassive {10^6-10^9
solar mass} black holes are closely connected with the formation and
evolutionary history of large galaxies, especially their bulge
component. Two outstanding issues, however, remain unresolved. Can
central black holes form in the absence of a bulge? And does the mass
function of central black holes extend below 10^6 solar masses?
Intermediate-mass black holes {10^6 solar masses}, if they exist, may
offer important clues to the nature of the seeds of supermassive black
holes. Using the SDSS, our group has successfully uncovered a new
population of AGNs with intermediate-mass black holes that reside in
low-luminosity galaxies. However, very little is known about the
detailed morphologies or structural parameters of the host galaxies
themselves, including the crucial question of whether they have bulges
or not. Surprisingly, the majority of the targets of our Cycle 14
pilot program have structural properties similar to dwarf elliptical
galaxies. The statistics from this initial study, however, are really
too sparse to reach definitive conclusions on this important new class
of black holes. We wish to extend this study to a larger sample, by
using the Snapshot mode to obtain WFPC2 F814W images from a parent
sample of 175 AGNs with intermediate- mass black holes selected from
our final SDSS search. We are particularly keen to determine whether
the hosts contain bulges, and if so, how the fundamental plane
properties of the host depend on the mass of their central black
holes. We will also investigate the environment of this unique class
of AGNs.

WFPC2 11218

Snapshot Survey for Planetary Nebulae in Globular Clusters of the
Local Group

Planetary nebulae {PNe} in globular clusters {GCs} raise a number of
interesting issues related to stellar and galactic evolution. The
number of PNe known in Milky Way GCs, 4, is surprisingly low if one
assumes that all stars pass through a PN stage. However, it is likely
that the remnants of stars now evolving in Galactic GCs leave the AGB
so slowly that any ejected nebula dissipates long before the star
becomes hot enough to ionize it. Thus there should not be ANY PNe in
Milky Way GCs--but there are four! It has been suggested that these
PNe are the result of mergers of binary stars within GCs, i.e., that
they are descendants of blue stragglers. The frequency of occurrence
of PNe in external galaxies poses more questions, because it shows a
range of almost an order of magnitude. I propose a Snapshot survey
aimed at discovering PNe in the GC systems of Local Group galaxies
more distant than the Magellanic Clouds. These clusters, some of which
may be much younger than their counterparts in the Milky Way, might
contain many more PNe than those of our own galaxy. I will use the
standard technique of emission-line and continuum imaging, which
easily discloses PNe.

WFPC2 11795

WFPC2 Cycle 16 UV Earth Flats

Monitor flat field stability. This proposal obtains sequences of earth
streak flats to improve the quality of pipeline flat fields for the
WFPC2 UV filter set. These Earth flats will complement the UV earth
flat data obtained during cycles 8-15.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11455 GSAcq(2,1,1) failed, Scan Step Limit Exceeded on FGS 2 @
239/2049z GSAcq(2,1,1) scheduled 239/20:45:44 - 20:53:49z failed to
RGA Hold. Observations affected: WFPC #75-77 Proposal ID #11130.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

***************************** SCHEDULED***** SUCCESSFUL
FGS GSacq********************** 07************* 06
FGS REacq********************** 08************* 08
OBAD with Maneuver************* 30************* 30

SIGNIFICANT EVENTS: (None)