Daily Rpt #4981

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT #4981

PERIOD COVERED: 5am November 27 - 5am November 30, 2009 (DOY 331/10:00z-334/10:00z)

OBSERVATIONS SCHEDULED

WFC3/IR/S/C 11929

IR Dark Current Monitor

Analyses of ground test data showed that dark current signals are more
reliably removed from science data using darks taken with the same
exposure sequences as the science data, than with a single dark
current image scaled by desired exposure time. Therefore, dark current
images must be collected using all sample sequences that will be used
in science observations. These observations will be used to monitor
changes in the dark current of the WFC3-IR channel on a day-to-day
basis, and to build calibration dark current ramps for each of the
sample sequences to be used by Gos in Cycle 17. For each sample
sequence/array size combination, a median ramp will be created and
delivered to the calibration database system (CDBS).

WFC3/UVIS 11924

WFC3/UVIS External and Internal CTE Monitor

CCD detector Charge Transfer Inefficiency (CTI)-induced losses in
photometry and astrometry will be measured using observations of the
rich open cluster NGC6791 and with the EPER (Extended Pixel Edge
Response) method using tungsten lamp flat field exposures. Although we
do not expect to see CTE effects at the outset of Cycle 17, this CTE
monitoring program is the first of a multi-cycle program to monitor
and establish CTE-induced losses with time. We expect to measure CTE
effects with a precision comparable to the ACS measurements.

WFC3/IR 11920

WFC3 IR Image Quality

The IR imaging performance over the detector will be assessed
periodically (every 4 months) in two passbands to check for image
stability. The field around star 58 in the open cluster NGC188 is the
chosen target because it is sufficiently dense to provide good
sampling over the FOV while providing enough isolated stars to permit
accurate PSF (point spread function) measurement. It is available
year-round and used previously for ACS image quality assessment. The
field is astrometric, and astrometric guide stars will be used, so
that the plate scale and image orientation may also be determined if
necessary (as in SMOV proposals 11437 and 11443). Full frame images
will be obtained at each of 4 POSTARG offset positions designed to
improve sampling over the detector in F098M, F105W, and F160W. The
PSFs will be sampled at 4 positions with subpixel shifts in filters
F164N and F127M.

This proposal is a periodic repeat (once every 4 months) of the visits
in SMOV proposal 11437 (activity ID WFC3-24). The data will be
analyzed using the code and techniques described in ISR WFC3 2008-41
(Hartig). Profiles of encircled energy will be monitored and presented
in an ISR. If an update to the SIAF is needed, (V2, V3) locations of
stars will be obtained from the Flight Ops. Sensors and Calibrations
group at GSFC, the (V2, V3) of the reference pixel and the orientation
of the detector will be determined by the WFC3 group, and the
Telescopes group will update and deliver the SIAF to the PRDB branch.

The specific PSF metrics to be examined are encircled energy for
aperture diameter 0.25, 0.37, and 0.60 arcsec, FWHM, and sharpness.
(See ISR WFC3 2008-41 tables 2 and 3 and preceding text.) ~20 stars
distributed over the detector will be measured in each exposure for
each filter. The mean, rms, and rms of the mean will be determined for
each metric. The values determined from each of the 4 exposures per
filter within a visit will be compared to each other to see to what
extent they are affected by "breathing". Values will be compared from
visit to visit, starting with the values obtained during SMOV after
the fine alignment has been performed, to see if the measures of the
compactness of the PSF indicate degradation over time. The analysis
will be repeated for stars on the inner part of the detector and stars
on the outer part of the detector to check for differential
degradation of the PSF.

As an example of the analysis, one can examine the sharpness of the
F160W PSF exposures made during thermal vacuum testing (ISR WFC3
2008-41). To compare two samples, one can define the PSFs on each half
of the detector (lower and upper) as a sample (with 7 and 8 PSFs,
respectively). The mean, rms, and rms of the mean sharpness are
0.0826, 0.0067, and 0.0027 for one half, and 0.0773, 0.0049, and
0.0019 for the other. The difference of the means is 0.0053 and the
statistical error in that difference is 0.0033, so the difference is
not significant.

WFC3/UVIS 11908

Cycle 17: UVIS Bowtie Monitor

Ground testing revealed an intermittent hysteresis type effect in the
UVIS detector (both CCDs) at the level of ~1%, lasting hours to days.
Initially found via an unexpected bowtie-shaped feature in flatfield
ratios, subsequent lab tests on similar e2v devices have since shown
that it is also present as simply an overall offset across the entire
CCD, i.e., a QE offset without any discernable pattern. These lab
tests have further revealed that overexposing the detector to count
levels several times full well fills the traps and effectively
neutralizes the bowtie. Each visit in this proposal acquires a set of
three 3x3 binned internal flatfields: the first unsaturated image will
be used to detect any bowtie, the second, highly exposed image will
neutralize the bowtie if it is present, and the final image will allow
for verification that the bowtie is gone.

WFC3/UVIS 11905

WFC3 UVIS CCD Daily Monitor

The behavior of the WFC3 UVIS CCD will be monitored daily with a set
of full-frame, four-amp bias and dark frames. A smaller set of 2Kx4K
subarray biases are acquired at less frequent intervals throughout the
cycle to support subarray science observations. The internals from
this proposal, along with those from the anneal procedure (Proposal
11909), will be used to generate the necessary superbias and superdark
reference files for the calibration pipeline (CDBS).

ACS/WFC3 11879

CCD Daily Monitor (Part 1)

This program comprises basic tests for measuring the read noise and
dark current of the ACS WFC and for tracking the growth of hot pixels.
The recorded frames are used to create bias and dark reference images
for science data reduction and calibration. This program will be
executed four days per week (Mon, Wed, Fri, Sun) for the duration of
Cycle 17. To facilitate scheduling, this program is split into three
proposals. This proposal covers 352 orbits (22 weeks) from 31 August
2009 to 31 January 2010.

FGS 11875

Monitoring FGS2R2 Distortion and Alignment After SMOV4

This proposal monitors changes in the FGS2R2 distortion and alignment
after SMOV4 by observing selected stars in M35 in Position mode. Data
from each epoch are compared to track changes in FGS2R2. When the rate
of change becomes sufficiently slow, FGS2R2 will be cleared for a
mini-OFAD and FGS-FGS alignment calibration (carried out in another
phase 2 proposal).

STIS/CCD/MA1/MA2 11866

Echelle Grating Blaze Function Zero Points

We will observe the flux standard G191B2B, obtaining echelle spectra
in all primary and intermediate wavelength settings. While this was
done in cycle 10 (8915), the echelle blaze shift has proved to depend
sensitively on side of operation, time and the exact MSM positioning.
We therefore believe it is important to obtain a complete set of post-
repair data at default MSM position to allow a comprehensive solution
for the echelle blaze shifts on a repaired side 2.

STIS/CCD/MA1/MA2 11860

MAMA Spectroscopic Sensitivity and Focus Monitor

The purpose of this proposal is to monitor the sensitivity of each
MAMA grating mode to detect any change due to contamination or other
causes, and to also monitor the STIS focus in a spectroscopic and an
imaging mode.

STIS/CCD 11846

CCD Bias Monitor-Part 1

The purpose of this proposal is to monitor the bias in the 1x1, 1x2,
2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up
high-S/N superbiases and track the evolution of hot columns.

STIS/CCD 11844

CCD Dark Monitor Part 1

The purpose of this proposal is to monitor the darks for the STIS CCD.

FGS 11788

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.

ACS/WFC3 11735

The LSD Project: Dynamics, Merging and Stellar Populations of a Sample
of Well- Studied LBGs at z~3

A large observational effort with the ground-based ESO/VLT telescopes
allowed us to obtain deep, spatially-resolved, near-IR spectra of
complete sample of 11 Lyman-Break Galaxies at z~3.1. These
observations were used to obtain, for the first time, the metallicity
and the dynamical properties of a sample of objects that, albeit
small, is representative of the total population of the LBGs. We
propose to use HST to obtain high-resolution optical and near-IR
images of this sample of LBGs in order to study the broad-band
morphology and the stellar light distribution of these galaxies. These
images, exploiting the superior spatial resolution of HST images and
the low- background : 1- will allow a precise measure of the dynamical
mass from the velocity field derived with spectroscopy; 2- will permit
a comparison of the distribution of star formation (from the line
emission) with the underlying stellar population, and, 3- will be used
to check if the complex velocity field and the multiple line-emitting
regions detected in most targets can be ascribed to on-going mergers.
This accurate study will shed light on a number of unsolved problems
still affecting the knowledge of the LBGs.

WFC3/ACS/UVIS 11724

Direct Age Determination of the Local Group dE Galaxies NGC 147 and
NGC 185

The origin of dwarf elliptical (dE) galaxies remains a mystery and the
dE galaxies of the Local Group provide the best opportunity to study
this galaxy class in detail. We propose to obtain ACS photometry of
main sequence turnoff stars in the M31 dE satellites NGC 147 and NGC
185. Because these galaxies have little to no stars younger than 1
Gyr, resolving the main sequence turnoff is required to directly
quantify their star formation histories. NGC 147 and NGC 185 are the
only two dEs for which a clean measurement is feasible with the HST.
This proposal was accepted in Cycle 15, but little data were taken
before the failure of ACS. The main sequence turnoffs of NGC 147 and
NGC 185 are expected to be at an apparent magnitude of V=29; we
request F606W/F814W imaging one half magnitude fainter than this limit
(three magnitudes fainter than the deepest previous dE observations).
Quantifying the ratio of old to intermediate-age stars will allow us
to discriminate between competing models of dE formation. On-going
Keck/DEIMOS spectroscopy of several hundred red giant stars in each of
these two dE galaxies, coupled with dynamical modeling and spectral
synthesis, will complement the ACS measurement by providing
information on chemical abundance patterns, dark matter content and
internal dynamics. The proposed ACS data will be the first to directly
quantify the onset and duration of star formation episodes in dE
galaxies, and will thereby form the cornerstone in what promises to be
the most comprehensive study of this class of galaxies.

WFC3/UVIS/IR 11723

Imaging the Crab Nebula-Like Supernova Remnant 3C 58

The Galactic supernova remnant 3C 58 shares several important
properties with the Crab Nebula. It possesses a young, rapidly
spinning pulsar and an associated compact optical/IR synchrotron wind
nebula. This makes 3C 58, along with the Crab and PSR B0540-69 in the
LMC, only the third such PWN detected in the optical and IR. Also like
the Crab, 3C58 has been associated with a historically reported `guest
star', in this case, the apparent SN of 1181 CE. Its optical
nebulosity contains an unusually large fraction of shocked
circumstellar material, with the remnant's high-velocity, N-rich
ejecta knots exhibiting a strong bi-polar expansion asymmetry.

Despite having a relatively extensive optical nebula, it is the only
young and nearby Galactic SNR that has not yet been imaged by HST.
However, some recent deep, high- resolution Gemini images show a
surprising amount of fine-scale filament detail, revealing some
peculiar optical emission morphologies. Here we propose a WFC3 imaging
survey of 3C 58 in order to investigate: 1) the optical luminosity and
emission efficiency of the remnant's young, 65.7 ms pulsar PSR
J0205+6449 thereby providing a rare testing of pulsar emission models,
2) the effect of the remnant's expanding synchrotron nebula on the
formation of Rayleigh-Taylor instabilities in its optical filaments
like that observed so far only in the Crab through HST imaging, and 3)
the fine-scale structure of 3C 58's slow moving circumstellar and
high-velocity SN ejecta and the morphological and distribution
differences between them.

WFC3/UVIS 11657

The Population of Compact Planetary Nebulae in the Galactic Disk

We propose to secure narrow- and broad-band images of compact
planetary nebulae (PNe) in the Galactic Disk to study the missing link
of the early phases of post-AGB evolution. Ejected AGB envelopes
become PNe when the gas is ionized. PNe expand, and, when large
enough, can be studied in detail from the ground. In the interim, only
the HST capabilities can resolve their size, morphology, and central
stars. Our proposed observations will be the basis for a systematic
study of the onset of morphology. Dust properties of the proposed
targets will be available through approved Spitzer/IRS spectra, and so
will the abundances of the alpha-elements. We will be able thus to
explore the interconnection of morphology, dust grains, stellar
evolution, and populations. The target selection is suitable to
explore the nebular and stellar properties across the galactic disk,
and to set constraints on the galactic evolutionary models through the
analysis of metallicity and population gradients.

WFC3/UVIS/IR 11644

A Dynamical-Compositional Survey of the Kuiper Belt: A New Window Into
the Formation of the Outer Solar System

The eight planets overwhelmingly dominate the solar system by mass,
but their small numbers, coupled with their stochastic pasts, make it
impossible to construct a unique formation history from the dynamical
or compositional characteristics of them alone. In contrast, the huge
numbers of small bodies scattered throughout and even beyond the
planets, while insignificant by mass, provide an almost unlimited
number of probes of the statistical conditions, history, and
interactions in the solar system. To date, attempts to understand the
formation and evolution of the Kuiper Belt have largely been dynamical
simulations where a hypothesized starting condition is evolved under
the gravitational influence of the early giant planets and an attempt
is made to reproduce the current observed populations. With little
compositional information known for the real Kuiper Belt, the test
particles in the simulation are free to have any formation location
and history as long as they end at the correct point. Allowing
compositional information to guide and constrain the formation,
thermal, and collisional histories of these objects would add an
entire new dimension to our understanding of the evolution of the
outer solar system. While ground based compositional studies have hit
their flux limits already with only a few objects sampled, we propose
to exploit the new capabilities of WFC3 to perform the first ever
large-scale dynamical-compositional study of Kuiper Belt Objects
(KBOs) and their progeny to study the chemical, dynamical, and
collisional history of the region of the giant planets. The
sensitivity of the WFC3 observations will allow us to go up to two
magnitudes deeper than our ground based studies, allowing us the
capability of optimally selecting a target list for a large survey
rather than simply taking the few objects that can be measured, as we
have had to do to date. We have carefully constructed a sample of 120
objects which provides both overall breadth, for a general
understanding of these objects, plus a large enough number of objects
in the individual dynamical subclass to allow detailed comparison
between and within these groups. These objects will likely define the
core Kuiper Belt compositional sample for years to come. While we have
many specific results anticipated to come from this survey, as with
any project where the field is rich, our current knowledge level is
low, and a new instrument suddenly appears which can exploit vastly
larger segments of the population, the potential for discovery -- both
anticipated and not -- is extraordinary.

WFC3/ACS/UVIS 11603

A Comprehensive Study of Dust Formation in Type II Supernovae with
HST, Spitzer, and Gemini

The recent discovery of three extremely bright Type II SNe, (2007it,
2007oc, 2007od) gives us a unique opportunity to combine observations
with HST, Spitzer, and Gemini to study the little understood dust
formation process in Type II SNe. Priority 1 Spitzer Cycle 5 and band
1 Gemini 2008A time has already been approved for this project. Since
late-time Type II SNe are faint and tend to be in crowded fields, we
need the high sensitivity and high spatial resolution of ACS and
NICMOS/NIC2 for these observations. This project is motivated by the
recent detection of large amounts of dust in high redshift galaxies.
The dust in these high-z galaxies must come from young, massive stars
so Type II SNe could be potential sources. The mechanism and the
efficiency of dust condensation in Type II SN ejecta are not well
understood, largely due to the lack of observational data. We plan to
produce a unique dataset, combining spectroscopy and imaging in the
visible, near- and mid-IR covering the key phase, 400- 700 days after
maximum when dust is known to form in the SN ejecta. Therefore, we are
proposing for coordinated HST/NOAO observations (HST ACS, NICMOS/NIC2
& Gemini/GMOS and TReCS) which will be combined with our Spitzer Cycle
5 data to study these new bright SNe. The results of this program will
place strong constraints on the formation of dust seen in young high
redshift (z5) galaxies.

ACS/WFC3 11599

Distances of Planetary Nebulae from SNAPshots of Resolved Companions

Reliable distances to individual planetary nebulae (PNe) in the Milky
Way are needed to advance our understanding of their spatial
distribution, birthrates, influence on galactic chemistry, and the
luminosities and evolutionary states of their central stars (CSPN).
Few PNe have good distances, however. One of the best ways to remedy
this problem is to find resolved physical companions to the CSPN and
measure their distances by photometric main-sequence fitting. We have
previously used HST to identify and measure probable companions to 10
CSPN, based on angular separations and statistical arguments only. We
now propose to use HST to re-observe 48 PNe from that program for
which additional companions are possibly present. We then can use the
added criterion of common proper motion to confirm our original
candidate companions and identify new ones in cases that could not
confidently be studied before. We will image the region around each
CSPN in the V and I bands, and in some cases in the B band. Field
stars that appear close to the CSPN by chance will be revealed by
their relative proper motion during the 13+ years since our original
survey, leaving only genuine physical companions in our improved and
enlarged sample. This study will increase the number of Galactic PNe
with reliable distances by 50 percent and improve the distances to Pne
with previously known companions.

WFC3/UVIS 11594

A WFC3 Grism Survey for Lyman Limit Absorption at z=2

We propose to conduct a spectroscopic survey of Lyman limit absorbers
at redshifts 1.8 z 2.5, using WFC3 and the G280 grism. This
proposal intends to complete an approved Cycle 15 SNAP program
(10878), which was cut short due to the ACS failure. We have selected
64 quasars at 2.3 z 2.6 from the Sloan Digital Sky Survey
Spectroscopic Quasar Sample, for which no BAL signature is found at
the QSO redshift and no strong metal absorption lines are present at z
2.3 along the lines of sight. The survey has three main
observational goals. First, we will determine the redshift frequency
dn/dz of the LLS over the column density range 16.0 log(NHI) 20.3
cm^-2. Second, we will measure the column density frequency
distribution f(N) for the partial Lyman limit systems (PLLS) over the
column density range 16.0 log(NHI) 17.5 cm^-2. Third, we will
identify those sightlines which could provide a measurement of the
primordial D/H ratio. By carrying out this survey, we can also help
place meaningful constraints on two key quantities of cosmological
relevance. First, we will estimate the amount of metals in the LLS
using the f(N), and ground based observations of metal line
transitions. Second, by determining f(N) of the PLLS, we can constrain
the amplitude of the ionizing UV background at z~2 to a greater
precision. This survey is ideal for a snapshot observing program,
because the on-object integration times are all well below 30 minutes,
and follow-up observations from the ground require minimal telescope
time due to the QSO sample being bright.

WFC3/UVIS 11583

The Star Formation Rate In Nearby Elliptical Galaxies

Small amounts of star formation in normal elliptical galaxies are
suggested by several results: some surprisingly young ages from
optical line-index dating; cooling X-ray gas; and mid-IR dust
emission. Previously, it was difficult to detect low levels of star
formation, but UV imaging with WFPC3 will permit us to conclusively
identify individual O/B stars in nearby normal ellipticals by their UV
colors and magnitudes. This technique is orders of magnitude more
sensitive than previous methods, allowing detections of star formation
to levels of 1E-4 Msolar/yr. Proof of concept is provided by a very
long UV ACS observation of M87 that revealed many O/B stars. We
propose observations of four normal ellipticals where recent star
formation is likely. This will yield their star formation rates and
the locations of such activity.

WFC3/UVIS 11577

Opening New Windows on the Antennae with WFC3

We propose to use WFC3 to provide key observations of young star
clusters in "The Antennae" (NGC4038/39). Of prime importance is the
WFC3's ability to push the limiting UV magnitude FIVE mag deeper than
our previous WFPC2 observations. This corresponds to pushing the
limiting cluster mass from ~10**5 to ~10**3 solar masses for cluster
ages ~10**8 yrs. In addition, the much wider field of view of the WFC3
IR channel will allow us to map out both colliding disks rather than
just the Overlap Region between them. This will be especially
important for finding the youngest clusters that are still embedded in
their placental cocoons. The extensive set of narrow-band filters will
provide an effective means for determining the properties of shocks,
which are believed to be a primary triggering mechanism for star
formation. We will also use ACS in parallel with WFC3 to observe
portions of both the northern and southern tails at no additional
orbital cost. Finally, one additional primary WFC3 orbit will be used
to supplement exisiting HST observations of the star-forming "dwarf"
galaxy at the end of the southern tail. Hence, when completed we will
have full UBVI + H_alpha coverage (or more for the main galaxy) of
four different environments in the Antennae. In conjunction with the
extensive multi-wavelength database we have collected (both HST and
ground based) these observations will provide answers to fundamental
questions such as: How do these clusters form and evolve? How is star
formation triggered? How do star clusters affect the local and global
ISM, and the evolution of the galaxy as a whole? The Antennae galaxies
are the nearest example of a major disk--disk merger, and hence may
represent our best chance for understanding how mergers form
tremendous numbers of clusters and stars, both in the local universe
and during galaxy assembly at high redshift.

WFC3/UVIS 11565

A Search for Astrometric Companions to Very Low-Mass, Population II
Stars

We propose to carry out a Snapshot search for astrometric companions
in a subsample of very low-mass, halo subdwarfs identified within 120
parsecs of the Sun. These ultra-cool M subdwarfs are local
representatives of the lowest-mass H burning objects from the Galactic
Population II. The expected 3-4 astrometric doubles that will be
discovered will be invaluable in that they will be the first systems
from which gravitational masses of metal-poor stars at the bottom of
the main sequence can be directly measured.

NIC2/WFC3/IR 11548

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

We propose NICMOS and WFC3/IR 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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

#12109 GSAcq(1,2,1) @331/21:48:17z resulted in FL backup (2,0,2)
@331/21:50z

Observations possibly affected: WFC3 #175 Proposal #11565, WFC3 #176
Proposal #11908.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

SCHEDULED SUCCESSFUL
FGS GSAcq 23 23
FGS REAcq 23 23
OBAD with Maneuver 19 19

SIGNIFICANT EVENTS: (None)