Daily Report #4495

Notice: Due to the conversion of some ACS WFC or HRC observations into
WFPC2, or NICMOS observations after the loss of ACS CCD science capability
in January, there may be an occasional discrepancy between a proposal's
listed (and correct) instrument usage and the abstract that follows it.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4495

PERIOD COVERED: UT November 27, 2007 (DOY 331)

OBSERVATIONS SCHEDULED

WFPC2 10905

The Dynamic State of the Dwarf Galaxy Rich Canes Venatici I Region

With accurate distances, the nearest groups of galaxies can be resolved in 3
dimensions and the radial component of the motions of galaxies due to local
density perturbations can be distinquished from cosmological expansion
components. Currently, with the ACS, galaxy distances within 8 Mpc can be
measured effectively and efficiently by detecting the tip of the red giant
branch {TRGB}. Of four principal groups at high galactic latitude in this
domain, the Canes Venatici I Group {a} is the least studied, {b} is the most
populated, though overwhelmingly by dwarf galaxies, and {c} is likely the
least dynamically evolved. It is speculated that galaxies in low mass groups
may fail to retain baryons as effectively as those in high mass groups,
resulting in significantly higher mass-to-light ratios. The CVn I Group is
suspected to lie in the mass regime where the speculated astrophysical
processes that affect baryon retention are becoming important.

NIC1/NIC2/NIC3 8794

NICMOS Post-SAA calibration - CR Persistence Part 5

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 DARKs. 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 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.

NIC3 11082

NICMOS Imaging of GOODS: Probing the Evolution of the Earliest Massive
Galaxies, Galaxies Beyond Reionization, and the High Redshift Obscured
Universe

(uses ACS/SBC and WFPC2)

Deep near-infrared imaging provides the only avenue towards understanding a
host of astrophysical problems, including: finding galaxies and AGN at z
7, the evolution of the most massive galaxies, the triggering of star
formation in dusty galaxies, and revealing properties of obscured AGN. As
such, we propose to observe 60 selected areas of the GOODS North and South
fields with NICMOS Camera 3 in the F160W band pointed at known massive M
10^11 M_0 galaxies at z 2 discovered through deep Spitzer imaging. The
depth we will reach {26.5 AB at 5 sigma} in H_160 allows us to study the
internal properties of these galaxies, including their sizes and
morphologies, and to understand how scaling relations such as the Kormendy
relationship evolved. Although NIC3 is out of focus and undersampled, it is
currently our best opportunity to study these galaxies, while also sampling
enough area to perform a general NIR survey 1/3 the size of an ACS GOODS
field. These data will be a significant resource, invaluable for many other
science goals, including discovering high redshift galaxies at z 7, the
evolution of galaxies onto the Hubble sequence, as well as examining
obscured AGN and dusty star formation at z 1.5. The GOODS fields are the
natural location for HST to perform a deep NICMOS imaging program, as
extensive data from space and ground based observatories such as Chandra,
GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT, and the VLA are currently
available for these regions. Deep high-resolution near-infrared observations
are the one missing ingredient to this survey, filling in an important gap
to create the deepest, largest, and most uniform data set for studying the
faint and distant universe. The importance of these images will increase
with time as new facilities come on line, most notably WFC3 and ALMA, and
for the planning of future JWST observations.

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 11178

Probing Solar System History with Orbits, Masses, and Colors of
Transneptunian Binaries

The recent discovery of numerous transneptunian binaries {TNBs} opens a
window into dynamical conditions in the protoplanetary disk where they
formed as well as the history of subsequent events which sculpted the outer
Solar System and emplaced them onto their present day heliocentric orbits.
To date, at least 47 TNBs have been discovered, but only about a dozen have
had their mutual orbits and separate colors determined, frustrating their
use to investigate numerous important scientific questions. The current
shortage of data especially cripples scientific investigations requiring
statistical comparisons among the ensemble characteristics. We propose to
obtain sufficient astrometry and photometry of 23 TNBs to compute their
mutual orbits and system masses and to determine separate primary and
secondary colors, roughly tripling the sample for which this information is
known, as well as extending it to include systems of two near-equal size
bodies. To make the most efficient possible use of HST, we will use a Monte
Carlo technique to optimally schedule our observations.

WFPC2 11289

SL2S: The Strong Lensing Legacy Survey

Recent systematic surveys of strong galaxy-galaxy lenses {CLASS, SLACS,
GOODS, etc.} are producing spectacular results for galaxy masses roughly
below a transition mass M~10^13 Mo. The observed lens properties and their
evolution up to z~0.2, consistent with numerical simulations, can be
described by isothermal elliptical potentials. In contrast, modeling of
giant arcs in X-ray luminous clusters {halo masses M ~10^13 Mo} favors NFW
mass profiles, suggesting that dark matter halos are not significantly
affected by baryon cooling. Until recently, lensing surveys were neither
deep nor extended enough to probe the intermediate mass density regime,
which is fundamental for understanding the assembly of structures. The CFHT
Legacy Survey now covers 125 square degrees, and thus offers a large
reservoir of strong lenses probing a large range of mass densities up to
z~1. We have extracted a list of 150 strong lenses using the most recent
CFHTLS data release via automated procedures. Following our first SNAPSHOT
proposal in cycle 15, we propose to continue the Hubble follow-up targeting
a larger list of 130 lensing candidates. These are intermediate mass range
candidates {between galaxies and clusters} that are selected in the redshift
range of 0.2-1 with no a priori X-ray selection. The HST resolution is
necessary for confirming the lensing candidates, accurate modeling of the
lenses, and probing the total mass concentration in galaxy groups up to z~1
with the largest unbiased sample available 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 08 08
FGS REacq 06 06
OBAD with Maneuver 26 26

SIGNIFICANT EVENTS: (None)