HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #4895
PERIOD COVERED: 5am July 24 - 5am July 27, 2009 (DOY
205/09:00z-208/09:00z)
OBSERVATIONS SCHEDULED
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 11849
STIS CCD Hot Pixel Annealing
This purpose of this activity is to repair radiation
induced hot pixel
damage to the STIS CCD by warming the CCD to the ambient
instrument
temperature and annealing radiation damaged pixels.
Radiation damage creates hot pixels in the STIS CCD
Detector. Many of
these hot pixels can be repaired by warming the CCD from
its normal
operating temperature near - 83 deg. C to the ambient
instrument
temperature (~ +5 deg. C) for several hours. The number of
hot pixels
repaired is a function of annealing temperature. The
effectiveness of
the CCD hot pixel annealing process is assessed by
measuring the dark
current behavior before and after annealing and by
searching for any
window contamination effects.
WFC3 11808
WFC3 UVIS Bowtie Monitor
The UVIS detector was observed during ground testing to
occasionally
exhibit flat field and dark variations with a bowtie
pattern. These
variations are most significant as ~1% flat field (gain)
variations
across the field of view. It is believed that this
represents a state or
condition into which the detector can transition for
reasons and under
circumstances which are not currently understood. It is
also very
unlikely that most science observations will determine the
state (bowtie
or no-bowtie) of the detector. Ground test data indicates
that this
state is long lived (many hours to ~one day). Hysteresis
or memory of
past light exposure is also associated with this state.
Recent evidence suggests that exposing the detector to
~200k to 500k
electrons may quench this state. This proposal obtains an
internal flat
field sequence of three exposures: one at 10x full well
with two at 0.5x
full well immediately before and after. Each exposure is
3x3 binned to
reduce the data volume required.
These visits should be scheduled 2x per day until further
direction is
provided.
FGS 11704
The Ages of Globular Clusters and the Population II
Distance Scale
Globular clusters are the oldest objects in the universe
whose age can
be accurately determined. The dominant error in globular
cluster age
determinations is the uncertain Population II distance
scale. We propose
to use FGS 1r to obtain parallaxes with an accuracy of 0.2
milliarcsecond for 9 main sequence stars with [Fe/H] <
-1.5. This will
determine the absolute magnitude of these stars with accuracies
of 0.04
to 0.06mag. This data will be used to determine the
distance to 24
metal-poor globular clusters using main sequence fitting.
These
distances (with errors of 0.05 mag) will be used to
determine the ages
of globular clusters using the luminosity of the subgiant
branch as an
age indicator. This will yield absolute ages with an
accuracy 5%, about
a factor of two improvement over current estimates.
Coupled with
existing parallaxes for more metal-rich stars, we will be
able to
accurately determine the age for globular clusters over a
wide range of
metallicities in order to study the early formation
history of the Milky
Way and provide an independent estimate of the age of the
universe.
The Hipparcos database contains only 1 star with [Fe/H]
< -1.4 and an
absolute magnitude error less than 0.18 mag which is
suitable for use in
main sequence fitting. Previous attempts at main sequence
fitting to
metal-poor globular clusters have had to rely on
theoretical
calibrations of the color of the main sequence. Our HST
parallax program
will remove this source of possible systematic error and
yield distances
to metal- poor globular clusters which are significantly
more accurate
than possible with the current parallax data. The HST
parallax data will
have errors which are 10 times smaller than the current
parallax data.
Using the HST parallaxes, we will obtain main sequence
fitting distances
to 11 globular clusters which contain over 500 RR Lyrae
stars. This will
allow us to calibrate the absolute magnitude of RR Lyrae
stars, a
commonly used Population II distance indicator.
ACS/WFC3 11604
The Nuclear Structure of OH Megamaser Galaxies
We propose a snapshot survey of a complete sample of 80 OH
megamaser
galaxies. Each galaxy will be imaged with the ACS/WFC
through F814W and
a linear ramp filter (FR656N or FR716N or FR782N or
FR853N) allowing us
to study both the spheroid and the gas morphology in
Halpha + [
will use the 9% ramps FR647M (5370-7570 angstroms)
centered at 7000
angstroms and FR914M (7570-10, 719 angstroms) 8000
angstroms for
continuum subtraction for the high and low z objects
respectively. OH
megamaser galaxies (OHMG) form an important class of
ultraluminous
IR-galaxies (ULIRGs) whose maser lines emit QSO-like
luminosities.
ULIRGs in general are associated with recent mergers but
it is often
unclear whether their power output is dominated by
starbursts or a
hidden QSO because of the high absorbing columns which
hide their nuclei
even at X-ray wavelengths. In contrast, OHMG exhibit
strong evidence for
the presence of an energetically important and recently
triggered active
nucleus. In particular it is clear that much of the gas
must have
already collapsed to form a nuclear disk which may be the
progenitor of
a circum-nuclear torus, a key element of the unified
scheme of AGN. A
great advantage of studying OHMG systems over the general
ULIRG
population, is that the circum-nuclear disks are
effectively "fixed" at
an inner, edge on, orientation, eliminating varying
inclination as a
nuisance parameter. We will use the HST observations in
conjunction with
existing maser and spectroscopic data to construct a
detailed picture of
the circum-nuclear regions of a hitherto relatively
neglected class of
galaxy that may hold the key to understanding the
relationship between
galaxy mergers, nuclear star-formation, and the growth of
massive black
holes and the triggering of nuclear activity.
COS 11484
COS FUV Optics Alignment and Focus
After FUV detector functionality has been confirmed in COS25
(program
11483) and the initial focus updates determined in COS08
and
(programs 11468 and 11469), a sequence of 13 FUV
focus-sweep exposures
of a sharp-lined external target will be made with each
grating (4
orbits per grating) to perform a fine-focus sweep. After
the data are
analyzed, a patchable constant SMS update of OSM1 focus
for each grating
will be uplinked. A verification visit will be executed
after the
uplink. Observations require high S/N and should be taken
in TIME-TAG
(FLASH=YES) mode.
COS 11478
COS NUV Flat Fields
Acquire long NUV flat field exposures using the internal
deuterium
calibration lamp with the G185M grating. Use central
wavelengths of 1835
angstroms, 1850 angstroms, and 1864 angstroms. Based on
data taken
during thermal vacuum testing in 2003 (Test 1750), a total
of 65,000
seconds of data should be sufficient to obtain ~7.5x10^7
total counts in
the science region of the detector (> 200 counts per
pixel, or 1800
counts per 3 x 3 pixel resolution element).
This is SMOV4 Activity COS-18.
COS 11469
COS NUV Optics Alignment and Focus
This program has stringent guide star and timing
requirements. Refer to
the observing description section for complete details.
This program determines the fine focus using NUV MIRRORA
exposures of
the same target as COS08 (program 11468 -
This program must commence execution approximately 48
hours after
completion of visit 1 of COS08 and as soon as possible
after the uplink
in visit 2 of COS08. Three fine focus visits are executed
to establish
on-orbit nominal focus. Two detailed verification visits
are executed
after the three focus-sweep visits. Approximately 48 hours
after each
odd- numbered visit an uplink of new information is
required.
COS05 11466
NUV Detector Dark
Measure the NUV detector dark rate by taking long science
exposures with
no light on the detector. The detector dark rate and
spatial
distribution of counts will be compared to pre-launch data
in order to
verify the nominal operation of the detector, and for use
in the CalCOS
calibration pipeline. Variations of count rate as a
function of orbital
position will be analyzed to find dependence of dark rate
on proximity
to the SAA.
ACS 11465
ACS CCD Monitoring and Calibration for WFC3
This program is a smaller version of our routine CCD
monitoring program,
designed to run throughout SMOV, after which our regular
Cycle 17
proposal will begin. This program obtains the bias and
dark frames
needed to generate reference files for calibrating science
data, and
allows us to monitor detector noise and the growth of hot
pixels.
WFC3 11446
WFC3 UVIS Dark Current, Readnoise, and CTE
This proposal obtains full-frame, four-amp readout bias
and dark frames
at regularly- spaced intervals throughout SMOV in order to
assess and
monitor dark current, bad (warm, hot, dead) pixels, and
readnoise. In
addition, a set of internals using the WFC3 calsystem are
taken to
provide a baseline CTE measurement. WFC3-33
WFC3 11432
UVIS Internal Flats
This proposal will be used to assess the stability of the
flat field
structure for the UVIS detector. Flat fields will be
obtained for all
filters using the internal D2 and Tungsten lamps.
This proposal corresponds to Activity Description ID WF19.
It should
execute only after the following proposals have executed:
WF08 - 11421
WF09 - 11422 WF11 - 11424 WF15 - 11428
STIS07 11404
CCD Dark and Bias Monitor for SMOV4/Cycle 17 Activity
STIS-07
Monitor the darks for the STIS CCD. 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.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
#11947
GSAcq(2,1,1) Failed due to Search Radius Limit Exceeded
@ 205/21:21:13z
Observations
affected: WFC3 103 and 104, proposal 11502;
WFC3 105 to 107, proposal 11432; STIS 32 and 33,
proposal 11849
#11948
GSAcq(1,2,1) Failed to RGA Hold due to Search Radius Limit
Exceeded on FGS 2 @ 206/14:54:00z
Observations affected: WFC3 126 and 127, proposal 11502
#11950
GSAcq(1,2,1) and 4 associated REAcqs failed to RGA Hold
due to Search Radius Limit Exceeded on FGS-2 @
207/13:15-19:45z.
Observations affected: WFC3 139 to 149, proposal 11502;
STIS 52 to 56, proposal 11404
#11951
GSAcq(1,21) Failed due to Search Radius Limit Exceeded on
FGS 2 @ 207/21:15:58z
Observations
affected: WFC3 150 to 152, proposal 11502
COMPLETED OPS REQUESTS:
#18644-0
Realtime OBAD with Correction @ 205/12:56z
#18645-0
Genslew for Proposal 11469 (Slot 7) @ 205/14:21z
#18646-0
Genslew for Proposal 11484 (Slot 8) @ 205/14:23z
#18648-0
Genslew for Proposal 11484 (Slot 9) @ 205/14:28z
#18650-0
Genslew for Proposal 11487 (Slot 1) @ 205/22:07z
#18638-1 Patch
ACS ASIC FAC 3.4 to Correctly Manage ASIC Single
Bit Errors @ 205/16:04z
#18568-1 LBBIAS
Updates for Extended Gyro Guiding Intervals
(Generic) @ 205/16:11z
#18642-1 Patch
STIS OMBT1 NSSC Limit in Table 3 @ 205/17:42z
#18649-0
Realtime OBAD with Correction @ 205/17:44z
#18651-0 Update
COS OSM Positions in FSW @ 206/01:58z
#18568-1 LBBIAS
Updates for Extended Gyro Guiding Intervals @
207/19:42z
#18602-1:
Adjust NCS CPL Setpoint (to 0 degC in 4 steps) @
208/00:51-02:29z
COMPLETED OPS NOTES: (NONE)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
17
12
FGS
REAcq
27
18
OBAD with
Maneuver
18
18
SIGNIFICANT EVENTS:
Observations Affected by loss of 5
REAcqs (205/10:15-16:35z) associated with
previously listed HSTAR #11944 (DR
# 4894) GSAcq 205/08:40z failure: WFC3 #94-101,
Proposal #11502; COS #226-227,
Proposal #11466; and STIS #15-25,
Proposal #11404;
ACS ASIC FAC 3.4 was patched to
correctly manage ASIC Single Bit Errors with
Ops Request #18638 @205/16:04z
STIS NSSC1 OMBT1 temperature
safing limit was increased to 37.6 dgC with
Ops Request #18642 @205/17:42z.