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 z>7, 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)