Daily Report #4922

HUBBLE SPACE TELESCOPE - Continuing to Collect World Class Science

DAILY REPORT****** #4922

PERIOD COVERED: 5am September 1 - 5am September 2, 2009 (DOY
244/09:00z-245/09:00z)

OBSERVATIONS SCHEDULED

ACS/WFC3 11882

CCD Hot Pixel Annealing

All the data for this program is acquired using internal targets
(lamps) only, so all of the exposures should be taken during Earth
occultation time (but not during SAA passages). This program emulates
the ACS pre-flight ground calibration and post-launch SMOV testing
(program 8948), so that results from each epoch can be directly
compared. Extended Pixel Edge Response (EPER) and First Pixel Response
(FPR) data will be obtained over a range of signal levels for the Wide
Field Channel (WFC). The High Resolution Channel (HRC) visits have
been removed since it could not be repaired during SM4.

COS/FUV 11488

Internal FUV Wavelength Verification

This program will be executed after the uplink of the OSM1 position
updates derived from the determination of the wavelength-scale zero
points and desired spectral ranges for each grating in Activity COS29
(Program 11487 - COS FUV Internal/External Wavelength Scales). This
program will verify that the operational spectral ranges for each
grating, central wavelength, and FP-POS are those desired. Subsequent
to a successful verification, COS FUV ERO observations that require
accurate wavelength scales (if any) and FUV science can be enabled. An
internal wavelength calibration spectrum using the default PtNe lamp
(lamp 1) with each FUV grating at each central wavelength setting and
each FP-POS position will be obtained for the verification. Additional
exposures and waits between certain exposures will be required to
avoid - and to evaluate - mechanism drifts.

COS/FUV 11491

COS FUV External Flat Fields

Obtain external spectra of flat field targets at different positions
along the cross- dispersion direction of the FUV detector (and at a
variety of FP-POS positions) in order to obtain an FUV flat field. The
choices of gratings and positions of the target in the aperture have
been made in order to maximize the coverage on the detector in the
cross-dispersion direction and cover the entire region where science
spectra will fall.

COS/FUV 11897

FUV Spectroscopic Sensitivity Monitoring

The purpose of this proposal is to monitor sensitivity in each FUV
grating mode to detect any changes due to contamination or other
causes.

COS/NUV 11896

NUV Spectroscopic Sensitivity Monitoring

The purpose of this proposal is to monitor sensitivity of each NUV
grating mode to detect any changes due to contamination or other
causes.

FGS 11706

The Parallax of the Planet Host Star XO-3

We will use HST+FGS to measure the parallax of the transiting planet
host star XO 3. The resulting accurate distance measurement will
provide the most accurate radius determination to date for this
massive extrasolar planet (XO-3B), allowing us to critically test
current giant extrasolar planet structure models. These observations
will also constrain the amount of heating that may be produced inside
XO-3B by tides raised on the planet as it moves through its 3.2
d-eccentric (e ~ 0.22) orbit.

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.

FGS 11789

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.

STIS/CCD 11843

STIS CCD Performance Monitor

This activity measures the baseline performance and commandability of
the CCD subsystem. Only primary amplifier D is used. Bias and
Flatfield exposures are taken in order to measure bias level, read
noise, CTE, and gain. Numerous bias frames are taken to permit
construction of "superbias" frames in which the effects of read noise
have been rendered negligible. Full frame and binned observations are
made, with binning factors of 2 x 1, 1 x 2, 2 x 2. Bias frames are
taken in subarray readouts to check the bias level for ACQ and
ACQ/PEAK observations. All exposures are internals.

STIS/CCD 11844

CCD Dark Monitor Part 1

Monitor the darks for the STIS CCD.

STIS/CCD 11846

CCD Bias Monitor-Part 1

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 11850

CCD Sparse Field CTE Internal

CTE measurements are made using the "internal sparse field test",
along the parallel axis. The "Pos=" optional parameter, introduced
during Cycle 11, is used to provide off- center MSM positionings of
some slits. All exposures are internals.

STIS/CCD 11852

STIS CCD Spectroscopic Flats C17

Obtain pixel-to-pixel lamp flat fields for the STIS CCD in
spectroscopic mode.

STIS20 11402

STIS-20 NUV MAMA Dark Monitor

The STIS NUV-MAMA dark current is dominated by a phosphorescent glow
from the detector window. Meta-stable states in this window are
populated by cosmic ray impacts, which, days later, can be thermally
excited to an unstable state from which they decay, emitting a UV
photon. The equilibrium population of these meta-stable states is
larger at lower temperatures; so warming up the detector from its cold
safing will lead to a large, but temporary, increase in the dark
current.

To monitor the decay of this glow, and to determine the equilibrium
dark current for Cycle 17, four 1380s NUV-MAMA ACCUM mode darks should
be taken each week during the SMOV period. Once the observed dark
current has reached an approximate equilibrium with the mean detector
temperature, the frequency of this monitor can be reduced to one pair
of darks per week.

WFC3/ACS/IR 11563

Galaxies at z~7-10 in the Reionization Epoch: Luminosity Functions to
0.2L* from Deep IR Imaging of the HUDF and HUDF05 Fields

The first generations of galaxies were assembled around redshifts
z~7-10+, just 500-800 Myr after recombination, in the heart of the
reionization of the universe. We know very little about galaxies in
this period. Despite great effort with HST and other telescopes, less
than ~15 galaxies have been reliably detected so far at z7,
contrasting with the ~1000 galaxies detected to date at z~6, just
200-400 Myr later, near the end of the reionization epoch. WFC3 IR can
dramatically change this situation, enabling derivation of the galaxy
luminosity function and its shape at z~7-8 to well below L*,
measurement of the UV luminosity density at z~7-8 and z~8-9, and
estimates of the contribution of galaxies to reionization at these
epochs, as well as characterization of their properties (sizes,
structure, colors). A quantitative leap in our understanding of early
galaxies, and the timescales of their buildup, requires a total sample
of ~100 galaxies at z~7-8 to ~29 AB mag. We can achieve this with 192
WFC3 IR orbits on three disjoint fields (minimizing cosmic variance):
the HUDF and the two nearby deep fields of the HUDF05. Our program
uses three WFC3 IR filters, and leverages over 600 orbits of existing
ACS data, to identify, with low contamination, a large sample of over
100 objects at z~7-8, a very useful sample of ~23 at z~8-9, and limits
at z~10. By careful placement of the WFC3 IR and parallel ACS
pointings, we also enhance the optical ACS imaging on the HUDF and a
HUDF05 field. We stress (1) the need to go deep, which is paramount to
define L*, the shape, and the slope alpha of the luminosity function
(LF) at these high redshifts; and (2) the far superior performance of
our strategy, compared with the use of strong lensing clusters, in
detecting significant samples of faint z~7-8 galaxies to derive their
luminosity function and UV ionizing flux. Our recent z~7.4 NICMOS
results show that wide-area IR surveys, even of GOODS-like depth,
simply do not reach faint enough at z~7-9 to meet the LF and UV flux
objectives. In the spirit of the HDF and the HUDF, we will waive any
proprietary period, and will also deliver the reduced data to STScI.
The proposed data will provide a Legacy resource of great value for a
wide range of archival science investigations of galaxies at redshifts
z~2-9. The data are likely to remain the deepest IR/optical images
until JWST is launched, and will provide sources for spectroscopic
followup by JWST, ALMA and EVLA.

WFC3/IR 11915

IR Internal Flat Fields

This program is the same as 11433 (SMOV) and depends on the completion
of the IR initial alignment (Program 11425). This version contains
three instances of 37 internal orbits: to be scheduled early, middle,
and near the end of Cycle 17, in order to use the entire 110-orbit
allocation.

In this test, we will study the stability and structure of the IR
channel flat field images through all filter elements in the WFC3-IR
channel. Flats will be monitored, i.e. to capture any temporal trends
in the flat fields and delta flats produced. High signal observations
will provide a map of the pixel-to-pixel flat field structure, as well
as identify the positions of any dust particles.

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 11714

Snapshot Survey for Planetary Nebulae in Local Group Globular
Clusters

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, four, 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 outside the Milky Way. These clusters, some of
which may be much younger than their counterparts in our galaxy, 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. This proposal continues a WFPC2 program started
in Cycle 16, but with the more powerful WFC3. As a by-product, the
survey will also produce color-magnitude diagrams for numerous
clusters for the first time, reaching down to the horizontal branch.

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 (11909),
will be used to generate the necessary superbias and superdark
reference files for the calibration pipeline (CDBS).

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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

12001 - GSAcq 1,2,1 scheduled from 244/21:59:48 - 244/22:06:30, failed
due to Search Radius Limit Exceeded on FGS-1.

Observations affected: COS 40 & 41 Proposal ID# 11897, WFC3 22
proposal ID# 11908.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

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

FGS GSAcq************** 8******************** 7
FGS REAcq************** 5******************** 5
OBAD with Maneuver **** 8******************** 8

SIGNIFICANT EVENTS: (None)