Daily Report #4669

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT #4669

PERIOD COVERED: 5am August 6 - 5am August 7, 2008 (DOY 219/0900z-220/0900z)

OBSERVATIONS SCHEDULED

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 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 11101

The Relevance of Mergers for Fueling AGNs: Answers from QSO Host Galaxies

The majority of QSOs are known to reside in centers of galaxies that look
like ellipticals. Numerical simulations have shown that remnants of galaxy
mergers often closely resemble elliptical galaxies. However, it is still
strongly debated whether the majority of QSO host galaxies are indeed the
result of relatively recent mergers or whether they are completely analogous
to inactive ellipticals to which nothing interesting has happened recently.
To address this question, we recently obtained deep HST ACS images for five
QSO host galaxies that were classified morphologically as ellipticals
{GO-10421}. This pilot study revealed striking signs of tidal interactions
such as ripples, tidal tails, and warped disks that were not detected in
previous studies. Our observations show that at least some "elliptical" QSO
host galaxies are the products of relatively recent merger events rather
than old galaxies formed at high redshift. However, the question remains
whether the host galaxies of classical QSOs are truly distinct from inactive
ellipticals and whether there is a connection between the merger events we
detect and the current nuclear activity. We must therefore place our results
into a larger statistical context. We are currently conducting an HST
archival study of inactive elliptical galaxies {AR- 10941} to form a control
sample. We now propose to obtain deep HST/WFPC2 images of 13 QSOs whose host
galaxies are classified as normal ellipticals. Comparing the results for
both samples will help us determine whether classical QSOs reside in normal
elliptical galaxies or not. Our recent pilot study of five QSOs indicates
that we can expect exciting results and deep insights into the host galaxy
morphology also for this larger sample of QSOs. A statistically meaningful
sample will help us determine the true fraction of QSO hosts that suffered
strong tidal interactions and thus, whether a merger is indeed a requirement
to trigger nuclear activity in the most luminous AGNs. In addition to our
primary science observations with WFPC2, we will obtain NICMOS3 parallel
observations with the overall goal to select and characterize galaxy
populations at high redshifts. The imaging will be among the deepest NICMOS
images: These NICMOS images are expected to go to a limit a little over 1
magnitude brighter than HUDF-NICMOS data, but over 13 widely separated
fields, with a total area about 1.5 times larger than HUDF- NICMOS. This
separation means that the survey will tend to average out effects of cosmic
variance. The NICMOS3 images will have sufficient resolution for an initial
characterization of galaxy morphologies, which is currently one of the most
active and promising areas in approaching the problem of the formation of
the first massive galaxies. The depth and area coverage of our proposed
NICMOS observations will also allow a careful study of the mass function of
galaxies at these redshifts. This provides a large and unbiased sample,
selected in terms of stellar mass and unaffected by cosmic variance, to
study the on-going star formation activity as a function of mass {i.e.
integrated star formation} at this very important epoch.

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.

NIC2 11197

Sweeping Away the Dust: Reliable Dark Energy with an Infrared Hubble Diagram

We propose building a high-z Hubble Diagram using type Ia supernovae
observed in the infrared rest-frame J-band. The infrared has a number of
exceptional properties. The effect of dust extinction is minimal, reducing a
major systematic that may be biasing dark energy measurements. Also, recent
work indicates that type Ia supernovae are true standard candles in the
infrared meaning that our Hubble diagram will be resistant to possible
evolution in the Phillip's relation over cosmic time. High signal-to-noise
measurements of 16 type Ia events at z~0.4 will be compared with an
independent optical Hubble diagram from the ESSENCE project to test for a
shift in the derived dark energy equation of state due to a systematic bias.
In Cycle 15 we obtained NICMOS photometry of 8 ESSENCE supernovae and are
awaiting template observations to place them on the IR Hubble diagram. Here
we request another 8 supernovae be studied in the final season of the
ESSENCE search. Because of the bright sky background, H-band photometry of
z~0.4 supernovae is not feasible from the ground. Only the superb image
quality and dark infrared sky seen by HST makes this test possible. This
experiment may also lead to a better, more reliable way of mapping the
expansion history of the universe with the Joint Dark Energy Mission.

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}.

WFPC2 11079

Treasury Imaging of Star Forming Regions in the Local Group: Complementing
the GALEX and NOAO Surveys

We propose to use WFPC2 to image the most interesting star-forming regions
in the Local Group galaxies, to resolve their young stellar populations. We
will use a set of filters including F170W, which is critical to detect and
characterize the most massive stars, to whose hot temperatures colors at
longer wavelengths are not sensitive. WFPC2's field of view ideally matches
the typical size of the star-forming regions, and its spatial resolution
allows us to measure individual stars, given the proximity of these
galaxies. The resulting H-R diagrams will enable studies of star- formation
properties in these regions, which cover largely differing metallicities {a
factor of 17, compared to the factor of 4 explored so far} and
characteristics. The results will further our understanding of the
star-formation process, of the interplay between massive stars and
environment, the properties of dust, and will provide the key to interpret
integrated measurements of star-formation indicators {UV, IR, Halpha}
available for several hundreds more distant galaxies. Our recent deep
surveys of these galaxies with GALEX {FUV, NUV} and ground-based imaging
{UBVRI, Halpha, [OIII] and [SII]} provided the identification of the most
relevant SF sites. In addition to our scientific analysis, we will provide
catalogs of HST photometry in 6 bands, matched corollary ground-based data,
and UV, Halpha and IR integrated measurements of the associations, for
comparison of integrated star-formation indices to the resolved populations.
We envisage an EPO component.

WFPC2 11122

Expanding PNe: Distances and Hydro Models

We propose to obtain repeat narrowband images of a sample of eighteen
planetary nebulae {PNe} which have HST/WFPC2 archival data spanning time
baselines of a decade. All of these targets have previous high
signal-to-noise WFPC2/PC observations and are sufficiently nearby to have
readily detectable expansion signatures after a few years. Our main
scientific objectives are {a} to determine precise distances to these PNe
based on their angular expansions, {b} to test detailed and highly
successful hydrodynamic models that predict nebular morphologies and
expansions for subsamples of round/elliptical and axisymmetric PNe, and {c}
to monitor the proper motions of nebular microstructures in an effort to
learn more about their physical nature and formation mechanisms. The
proposed observations will result in high-precision distances to a healthy
subsample of PNe, and from this their expansion ages, luminosities, CSPN
properties, and masses of their ionized cores. With good distances and our
hydro models, we will be able to determine fundamental parameters {such as
nebular and central star masses, luminosity, age}. The same images allow us
to monitor the changing overall ionization state and to search for the
surprisingly non-homologous growth patterns to bright elliptical PNe of the
same sort seen by Balick & Hajian {2004} in NGC 6543. Non-uniform growth is
a sure sign of active pressure imbalances within the nebula that require
careful hydro models to understand.

WFPC2 11203

A Search for Circumstellar Disks and Planetary-Mass Companions around Brown
Dwarfs in Taurus

During a 1-orbit program in Cycle 14, we used WFPC2 to obtain the first
direct image of a circumstellar disk around a brown dwarf. These data have
provided fundamental new constraints on the formation process of brown
dwarfs and the properties of their disks. To search for additional direct
detections of disks around brown dwarfs and to search for planetary-mass
companions to these objects, we propose a WFPC2 survey of 32 brown dwarfs in
the Taurus star-forming region.

WFPC2 11796

WFPC2 Cycle 16 Decontaminations and Associated Observations

This proposal is for the WFPC2 decons. Also included are instrument monitors
tied to decons: photometric stability check, focus monitor, pre- and
post-decon internals (bias, intflats, kspots, & darks), UV throughput check,
VISFLAT sweep, and internal UV flat check.

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 03 03
OBAD with Maneuver 30 30

SIGNIFICANT EVENTS: (None)