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Daily Report #4494



 
 
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Old November 27th 07, 03:51 PM posted to sci.astro.hubble
Cooper, Joe
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Default Daily Report #4494

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***** # 4494

PERIOD COVERED: UT November 26, 2007 (DOY 330)

OBSERVATIONS SCHEDULED

ACS/SBC 10840

The FUV fluxes of Tauri stars in the Taurus molecular cloud

Present and forthcoming ground-based and space surveys of the T Tauri
stars in the Taurus molecular cloud will provide information from high
energy stellar and accretion radiation to low energy solid state and
molecular emission from the disk, making those stars perfect
laboratories to carry out self-consistent studies of disk physics and
evolution. We propose to complete this wealth of information by
obtaining ACS/FUV spectra for a significant sample of Taurus T Tauri
stars, covering a range of accretion properties and dust evolutionary
stages. FUV fluxes carry ~ 10 - 100 more energy than X-rays into these
disks and are thus crucial gas heating agents and key to disk
dispersal by photoevaporation. These observations are a pre-requisite
to interpret observations with Spitzer, SOFIA, Herschel, and ALMA, and
will become one of the important legacies of HST to the star formation
community.

ACS/SBC WFPC2 11175

UV Imaging to Determine the Location of Residual Star Formation in
Galaxies Recently Arrived on the Red Sequence

We have identified a sample of low-redshift {z = 0.04 - 0.10} galaxies
that are candidates for recent arrival on the red sequence. They have
red optical colors indicative of old stellar populations, but blue
UV-optical colors that could indicate the presence of a small quantity
of continuing or very recent star formation. However, their spectra
lack the emission lines that characterize star-forming galaxies. We
propose to use ACS/SBC to obtain high- resolution imaging of the UV
flux in these galaxies, in order to determine the spatial distribution
of the last episode of star formation. WFPC2 imaging will provide B,
V, and I photometry to measure the main stellar light distribution of
the galaxy for comparison with the UV imaging, as well as to measure
color gradients and the distribution of interstellar dust. This
detailed morphological information will allow us to investigate the
hypothesis that these galaxies have recently stopped forming stars and
to compare the observed distribution of the last star formation with
predictions for several different mechanisms that may quench star
formation in galaxies.

WFPC2 11024

WFPC2 CYCLE 15 INTERNAL MONITOR

This calibration proposal is the Cycle 15 routine internal monitor for
WFPC2, to be run weekly to monitor the health of the cameras. A
variety of internal exposures are obtained in order to provide a
monitor of the integrity of the CCD camera electronics in both bays
{both gain 7 and gain 15 -- to test stability of gains and bias
levels}, a test for quantum efficiency in the CCDs, and a monitor for
possible buildup of contaminants on the CCD windows. These also
provide raw data for generating annual super-bias reference files for
the calibration pipeline.

FGS 11212

Filling the Period Gap for Massive Binaries

The current census of binaries among the massive O-type stars is
seriously incomplete for systems in the period range from years to
millennia because the radial velocity variations are too small and the
angular separations too close for easy detection. Here we propose to
discover binaries in this observational gap through a Faint Guidance
Sensor SNAP survey of relatively bright targets listed in the Galactic
O Star Catalog. Our primary goal is to determine the binary frequency
among those in the cluster/association, field, and runaway groups. The
results will help us assess the role of binaries in massive star
formation and in the processes that lead to the ejection of massive
stars from their natal clusters. The program will also lead to the
identification of new, close binaries that will be targets of long
term spectroscopic and high angular resolution observations to
determine their masses and distances. The results will also be
important for the interpretation of the spectra of suspected and newly
identified binary and multiple systems.

FGS 11299

Calibrating the Mass-Luminosity Relation at the End of the Main
Sequence

We propose to use HST-FGS1R to finish calibrating the mass-luminosity
relation for stars less massive than 0.5 Msun, with special emphasis
on objects near the stellar/substellar border. Our goals are to
determine Mv values to 0.05 magnitude and masses to 5%, and thereby
build the fundamental database of stellar masses that we will use to
test theoretical models as never before. This program uses the
combination of HST- FGS3/FGS1R at optical wavelengths, historical
infrared speckle data, ground-based parallax work, metallicity
studies, and radial velocity monitoring to examine nearby,
subarcsecond binary systems. The high precision separation and
position angle measurements with HST-FGS3/FGS1R {to 1 mas in the
separations} for these faint {V = 10-15} targets simply cannot be
equaled by any ground-based technique. As a result of these
measurements, we are deriving high quality luminosities and masses for
the components in the systems, and characterizing their spectral
energy distributions from 0.5 to 2.2 microns. One of the objects, GJ
1245 C with mass 0.074 +/- 0.002 Msun, is the only object known with
an accurate dynamical mass less than 0.10 Msun. The payoff of this
proposal is high because the six systems selected for final
observations in Cycles 15 and 16 have already been resolved during
Cycles 5-13 with HST FGS3/FGS1R and contain most of the reddest
objects for which accurate dynamical masses can be determined.

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 10852

Coronagraphic Polarimetry with NICMOS: Dust grain evolution in T Tauri
stars

The formation of planetary systems is intimately linked to the dust
population in circumstellar disks, thus understanding dust grain
evolution is essential to advancing our understanding of how planets
form. By combining {1} the coronagraphic polarimetry capabilities of
NICMOS, {2} powerful 3-D radiative transfer codes, and {3}
observations of objects known to span the Class II-III stellar
evolutionary phases, we will gain crucial insight into dust grain
growth. By observing objects representative of a known evolutionary
sequence of YSOs, we will be able to investigate how the dust
population evolves in size and distribution during the crucial
transition from a star+disk system to a system containing
planetesimals. When combine with our previous study on dust grain
evolution in the Class I-II phase, the proposed study will help to
establish the fundamental time scales for the depletion of ISM-like
grains: the first step in understanding the transformation from small
submicron sized dust grains, to large millimeter sized grains, and
untimely to planetary bodies.

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.

WFPC2 10915

ACS Nearby Galaxy Survey

Existing HST observations of nearby galaxies comprise a sparse and
highly non-uniform archive, making comprehensive comparative studies
among galaxies essentially impossible. We propose to secure HST's
lasting impact on the study of nearby galaxies by undertaking a
systematic, complete, and carefully crafted imaging survey of ALL
galaxies in the Local Universe outside the Local Group. The resulting
images will allow unprecedented measurements of: {1} the star
formation history {SFH} of a 100 Mpc^3 volume of the Universe with a
time resolution of Delta[log{t}]=0.25; {2} correlations between
spatially resolved SFHs and environment; {3} the structure and
properties of thick disks and stellar halos; and {4} the color
distributions, sizes, and specific frequencies of globular and disk
clusters as a function of galaxy mass and environment. To reach these
goals, we will use a combination of wide-field tiling and pointed deep
imaging to obtain uniform data on all 72 galaxies within a
volume-limited sample extending to ~3.5 Mpc, with an extension to the
M81 group. For each galaxy, the wide-field imaging will cover out to
~1.5 times the optical radius and will reach photometric depths of at
least 2 magnitudes below the tip of the red giant branch throughout
the limits of the survey volume. One additional deep pointing per
galaxy will reach SNR~10 for red clump stars, sufficient to recover
the ancient SFH from the color-magnitude diagram. This proposal will
produce photometric information for ~100 million stars {comparable to
the number in the SDSS survey} and uniform multi- color images of half
a square degree of sky. The resulting archive will establish the
fundamental optical database for nearby galaxies, in preparation for
the shift of high- resolution imaging to the near-infrared.

WFPC2 11070

WFPC2 CYCLE 15 Standard Darks - part II

This dark calibration program obtains dark frames every week in order
to provide data for the ongoing calibration of the CCD dark current
rate, and to monitor and characterize the evolution of hot pixels.
Over an extended period these data will also provide a monitor of
radiation damage to the CCDs.

WFPC2 11103

A Snapshot Survey of The Most Massive Clusters of Galaxies

We propose the continuation of our highly successful SNAPshot survey
of a sample of 125 very X-ray luminous clusters in the redshift range
0.3-0.7. As demonstrated by the 25 snapshots obtained so far in
Cycle14 and Cycle15 these systems frequently exhibit strong
gravitational lensing as well as spectacular examples of violent
galaxy interactions. The proposed observations will provide important
constraints on the cluster mass distributions, the physical nature of
galaxy-galaxy and galaxy-gas interactions in cluster cores, and a set
of optically bright, lensed galaxies for further 8-10m spectroscopy.
All of our primary science goals require only the detection and
characterization of high-surface-brightness features and are thus
achievable even at the reduced sensitivity of WFPC2. Because of their
high redshift and thus compact angular scale our target clusters are
less adversely affected by the smaller field of view of WFPC2 than
more nearby systems. Acknowledging the broad community interest in
this sample we waive our data rights for these observations. Due to a
clerical error at STScI our approved Cycle15 SNAP program was barred
from execution for 3 months and only 6 observations have been
performed to date - reinstating this SNAP at Cycle16 priority is of
paramount importance to reach meaningful statistics.

WFPC2 11128

Time Scales Of Bulge Formation In Nearby Galaxies

Traditionally, bulges are thought to fit well into galaxy formation
models of hierarchical merging. However, it is now becoming well
established that many bulges formed through internal, secular
evolution of the disk rather than through mergers. We call these
objects pseudobulges. Much is still unknown about pseudobulges, the
most pressing questions being: How, exactly, do they build up their
mass? How long does it take? And, how many exist? We are after an
answer to these questions. If pseudobulges form and evolve over longer
periods than the time between mergers, then a significant population
of pseudobulges is hard to explain within current galaxy formation
theories. A pseudobulge indicates that a galaxy has most likely not
undergone a major merger since the formation of the disk. The ages of
pseudobulges give us an estimate for the time scale of this quiescent
evolution. We propose to use 24 orbits of HST time to complete UBVIH
imaging on a sample of 33 nearby galaxies that we have observed with
Spitzer in the mid-IR. These data will be used to measure spatially
resolved stellar population parameters {mean stellar age, metallicity,
and star formation history}; comparing ages to star formation rates
allows us to accurately constrain the time scale of pseudobulge
formation. Our sample of bulges includes both pseudo- and classical
bulges, and evenly samples barred and unbarred galaxies. Most of our
sample is imaged, 13 have complete UBVIH coverage; we merely ask to
complete missing observations so that we may construct a uniform
sample for studying bulge formation. We also wish to compare the
stellar population parameters to a variety of bulge and global galaxy
properties including star formation rates, dynamics, internal bulge
morphology, structure from bulge-disk decompositions, and gas content.
Much of this data set is already or is being assembled. This will
allow us to derive methods of pseudobulge identification that can be
used to accurately count pseudobulges in large surveys. Aside from our
own science goals, we will present this broad set of data to the
community. Thus, we waive proprietary periods for all 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:

11080 - OBAD Failed Identification At 01:00:51 received 486 ESB 1902

"OBAD Failed ID". OBAD #1 was successful and showed values of: V1
-2.51, V2 -6.15, V3 -0.79, RSS 6.69. OBAD #2 failed and showed values
of: V1 -155021.17, V2 127693.68, V3 -177590.52, RSS 268096.31. OBAD
flag mnemonics showed GOBSTAT=255 (Attitude Determination Error) and
GCHACL09=1 or a failed state. The GSAcq @ 01:04:49 was successful. At
01:52:51 OBAD MAP showed values of: V1 -1.25, V2 -4.43, V3 4.90, RSS
6.72.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

********************** SCHEDULED***** SUCCESSFUL

FGS GSacq************** 09**************** 09
FGS REacq************** 03**************** 03
OBAD with Maneuver **** 24**************** 23

SIGNIFICANT EVENTS: (None)


 




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