HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT #4905
PERIOD
COVERED: 5am August 7 - 5am August 9, 2009 (DOY 219/09:00z-221/09:00z)
OBSERVATIONS
SCHEDULED
WFC3/UVI
12003
The
Impact Event on Jupiter in 2009
An
image of Jupiter taken on 19 July 2009 at 15 UT showed an anomalous
feature
in the southern hemisphere. The world-wide community responded
with
observations, and the subsequent data strongly suggest that an
impact
occurred during the 8 hours preceding that discovery image. The
Hubble
Space Telescope is the only facility that can provide
high-spatial-
resolution visible images of the impact site, and the only
facility
that can provide UV images that show the impactor's effect on
the
Jovian stratosphere. We request 7 orbits of HST time to characterize
this
rare event. We hope that two orbits can be as soon as is feasible
(Wednesday
or Thursday, 22 or 23 July). We would like a second pair
several
days later, perhaps Saturday. We request another 2 orbits the
following
week. The last, seventh, orbit can be several weeks or a month
later.
STIS/CCD
11889
Photometric
Cross-Calibration using Stellar Flux Standards
A)
Verify the ACS HRC and WFC photometric calibrations with a repeat
visit
to one of the three primary WDs. B) Measure the change in
sensitivity
with time for bright stars (which would include any small
CTE
contributions). C) Continue to investigate the ~2% discrepancy
between
ACS flux calibration and that of STIS (ACS ISR 2007-06). The
goal
is to measure any filter bandpass shifts in ACS or rule out the
possibility
of shifts as the primary contributors to the ACS/STIS
discrepancy
for cool stars.
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
11844
CCD
Dark Monitor Part 1
Monitor
the darks for the STIS CCD.
WFC3/UVI/IR
11832
The
Structure and Physics of the Youngest Radio Galaxies
We
propose to obtain X-ray images and spectra of two of the nearest and
X-ray
brightest compact symmetric objects. These objects are radio
sources
which have begun ejecting radio plasma within the last nsim
10000
years. The purpose of these observations is to discover their
X-ray
structure, measure their X-ray spectra and test the Wilson-Colbert
hypothesis
regarding the formation of radio-loud AGN. CSOs are ideal
targets
for this test because they are very small and very young. By
targeting
the very nearest objects we assure ourselves of the highest
possible
physical resolution. We are particularly looking for binary
black
holes (possibly found for one of our objects already) and/or
nascent
NLRs.
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.
ACS/WFC3
11734
The
Hosts of High Redshift Gamma-Ray Bursts
Gamma-ray
bursts are the most luminous explosive events known, acting as
beacons
to the high redshift universe. Long duration GRBs have their
origin
in the collapse of massive stars and thus select star forming
galaxies
across a wide range of redshift. Due to their bright afterglows
we
can study the details of GRB host galaxies via absorption
spectroscopy,
providing redshifts, column densities and metallicities
for
galaxies far too faint to be accessible directly with current
technology.
We have already obtained deep ground based observations for
many
hosts and here propose ACS/WFC3 and WFC3 observations of the fields
of
bursts at z>3 which are undetected in deep ground based images. These
observations
will study the hosts in emission, providing luminosities
and
morphologies and will enable the construction of a sample of high-z
galaxies
with more detailed physical properties than has ever been
possible
before.
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
11695
Searching
for the Bottom of the Initial Mass Function
The
measurement of the minimum mass of the IMF would provide a
fundamental
test of theories of star and planet formation. In a Cycle 13
program,
we used ACS and ground-based near-IR imaging and spectroscopy
to
measure the IMF down to a completeness limit of 10 M_Jup (i~24) in a
800"x1000"
area in the southern subcluster of the Chamaeleon I
star-forming
region (2 Myr, 160 pc). There is no sign of a low-mass
cutoff
in this IMF measurement. To provide a better constraint on the
minimum
mass of the IMF, we propose to obtain ACS images of this field
again
and use the two ACS epochs to identify substellar cluster members
down
to the detection limit of the data (i~27) via their proper motions.
In
this way, we will improve the completeness limit of our IMF
measurement
to 3 M_Jup. In addition, to improve the number statistics of
our
measurement of the substellar IMF in Chamaeleon I, we propose to
double
the number of objects in the IMF sample by performing ACS imaging
of
a second field toward the northern subcluster.
WFC3/UVI/IR
11685
Supermassive
Neutron Stars or Odd Binaries: Searching for Companions to
Pulsars
NGC 6440B and Terzan 5J
Recent
sensitive pulsar searches of globular clusters uncovered four
pulsars
with very high inferred masses, between 1.7 and 2.7 solar
masses.
These strongly constrain the behaviour of matter in the
ultra-dense
interiors of neutron stars, since for most models such
massive
neutron stars could not exist. All four masses are inferred from
the
measured advance of periastron with time, under the assumption that
it
is due to General Relativity only. Here, we propose to test whether
part
of the observed periastron advance could be induced by the
quadrupole
moment of a suitably large, rotationally distorted companion.
We
infer the radii such companions need to have and show that they would
be
relatively bright, easily detectable with HST. For one pulsar, M 5B,
we
find a plausible candidate counterpart in archival data. We propose
to
use 2 orbits with WFC3 to search for suitably large counterparts to
two
of the other systems, including the one with the highest inferred
mass.
WFC3/UVI
11680
The
Main Sequence Luminosity Function of Low-Mass Globular Clusters
Theoretical
work indicates that the dynamical evolution of globular
clusters
of low mass and low central concentration is strongly
determined
by mass-loss processes, such as stellar evaporation and tidal
stripping,
that can eventually lead to cluster dissolution. In fact,
mass
loss and cluster disruption is now considered to be a viable
explanation
for the form of the faint end of the Milky Way globular
cluster
luminosity function. A clear observational demonstration of the
prevalence
of cluster mass-loss would have ramifications not only for
the
dynamical evolution of individual globular clusters and their
internal
stellar mass distributions, but also for the relationships
between
halo field and cluster stars and the properties of globular
cluster
systems in galaxies. Our previous WFPC2 imaging of the low-mass
diffuse
halo cluster Palomar 5 revealed a main sequence deficient in
stars
compared to other low-concentration globular clusters of much
higher
mass, consistent with there having been a considerable loss of
stars
from this system. But is Pal 5 typical of low-mass,
low-concentration
halo clusters? We propose to place the mass-loss
scenario
on a firm observational footing (or otherwise) by using WFC3
imaging
to measure the main-sequence stellar mass functions of two of
the
lowest-mass lowest-concentration globular clusters in the Milky Way,
AM-4
and Palomar 13, in order to search for analogous evidence of
stellar
depletion.
ACS/WFC3
11669
The
Origins of Short Gamma-Ray Bursts
During
the past decade extraordinary progress has been made in
determining
the origin of long- duration gamma-ray bursts. It has been
conclusively
shown that these objects derive from the deaths of massive
stars.
Nonetheless, the origin of their observational cousins,
short-duration
gamma-ray bursts (SGRBs) remains a mystery. While SGRBs
are
widely thought to result from the inspiral of compact binaries, this
is
a conjecture. SGRBs have been found in elliptical galaxies, Abell
Clusters,
star-forming dwarfs and even an edge-on spiral. Whether they
primarily
result from an old population, a young population, or rapid
evolution
of binaries in globular clusters remains open.
Here
we propose to employ two related sets of observations which may
dramatically
advance our understanding of short bursts. The first is a
variant
of a technique that we pioneered and used to great effect in
elucidating
the origins of long-duration bursts. We will examine a
statistical
sample of hosts and measure the degree to which SGRB
locations
trace the red or blue light of their hosts, and thus old or
young
stellar populations. This will allow us to study the demographics
of
the SGRB population in a manner largely free of the distance
dependent
selection effects which have so far bedeviled this field. In
the
second line of attack we will use two targets of opportunity to
obtain
extremely precise positions of up to two nearby bursts -- one on
a
star-forming galaxy and the other on a elliptical. Observation of the
star-formation
galaxy could link at least some bursts directly to a
young
population; however, a discovery in later images of a globular
cluster
at the site of the explosion in an elliptical would provide
revolutionary
evidence that SGRBs are formed from compact binaries.
WFC3/UVI
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/UVI
11628
Globular
Cluster Candidates for Hosting a Central Black Hole
We
are continuing our study of the dynamical properties of globular
clusters
and we propose to obtain surface brightness profiles for high
concentration
clusters. Our results to date show that the distribution
of
central surface brightness slopes do not conform to standard models.
This
has important implications for how they form and evolve, and
suggest
the possible presence of central intermediate-mass black holes.
From
our previous archival proposals (AR-9542 and AR- 10315), we find
that
many high concentration globular clusters do not have flat cores or
steep
central cusps, instead they show weak cusps. Numerical simulations
suggest
that clusters with weak cusps may harbor intermediate-mass black
holes
and we have one confirmation of this connection with omega
Centauri.
This cluster shows a shallow cusp in its surface brightness
profile,
while kinematical measurements suggest the presence of a black
hole
in its center. Our goal is to extend these studies to a sample
containing
85% of the Galactic globular clusters with concentrations
higher
than 1.7 and look for objects departing from isothermal behavior.
The
ACS globular cluster survey (GO-10775) provides enough objects to
have
an excellent coverage of a wide range of galactic clusters, but it
contains
only a couple of the ones with high concentration. The proposed
sample
consists of clusters whose light profile can only be adequately
measured
from space-based imaging. This would take us close to
completeness
for the high concentration cases and therefore provide a
more
complete list of candidates for containing a central black hole.
The
dataset will also be combined with our existing kinematic
measurements
and enhanced with future kinematic studies to perform
detailed
dynamical modeling.
WFC3/UVI
11615
Hunting
for Optical Companions to Binary MSPs in Globular Clusters
Here
we present a proposal which exploits the re-newed potential of HST
after
the Service Mission 4 for probing the population of binary
Millisecond
Pulsars (MSPs) in Globular Clusters. In particular we intend
to:
(1) extend the search for optical counterparts in Terzan 5, by
pushing
the performance of the WFC3 IR channel to sample the entire MS
extension
down to M=0.1 Mo; (2) perform a deep multi-band search of MSP
companions
with the WFC3, in 3 clusters (namely NGC6440, M28 and M5),
where
recent radio observations have found particularly interesting
objects;
(3) derive an accurate radial velocity (with STIS) of the
puzzling
optical companion COM6266B recently discovered by our group, to
firmly
assess its cluster membership. This program is the result of a
large
collaboration among the three major groups (lead by Freire, Ransom
and
Possenti) which are performing extensive MSP search in GCs in the
radio
bands, and our group which has a large experience in performing
accurate
stellar photometry in crowded environments. This collaboration
has
produced a number of outstanding discoveries. In fact, three of the
6
optical counterparts to binary MSP companions known to date in GCs
have
been discovered by our group. The observations here proposed would
easily
double/triple the existing sample of known MSP companions,
allowing
the first meaningful approach to the study of the formation,
evolution
and recycling process of pulsar in GCs. Moreover, since most
of
binary MSPs in GCs are thought to form via stellar interactions in
the
high density core regions, the determination of the nature of the
companion
and the incidence of this collisionally-induced population has
a
significant impact on our knowledge of the cluster dynamics. Even more
interesting,
the study of the optical companions to NSs in GCs allows
one
to derive tighter constraints (than those obtainable for NS binaries
in
the Galactic field) on the system properties. This has, in turn, an
intrisic
importance for fundamental physics, since it offers the
opportunity
of measuring the mass of the NS and hence constraining the
equation
of state of matter at the nuclear equilibrium density.
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/UVI
11580
Watching
Young Planetary Nebulae Grow: The Movie
The
development of magneto-hydro gas dynamical models is the key to the
understanding
of both the physics (processes) and astronomy (initial
conditions)
of astrophysical nebulae of all sorts. The models are
reaching
their highest degree of accuracy when applied to and compared
against
pre Planetary Nebulae (pPNe) thanks to the simplicity, relative
lack
of extinction, and the detail of the imaging and kinematic data
that
have bcome available for these objects. The primary barrier to
progress
is inadequate kinematic data of pPNe against which the
predictions
models can be tested. Unlike PNe, pPNe do not emit emission
lines
for detailed Doppler measurements. Therefore it is essential to
find
another way to monitor the morphological evolution.
Only
HST can uncover the dynamics of the growth patterns by subtracting
multi-epoch
images spanning a decade or more. We have selected four pPNe
with
highly collimated outflows in different evolutionary stages for
which
high-quality first epoch images were obtained from 1996 to 2002.
All
of them display regularly shaped thin rims, sharp edges, and
symmetric
pairs of knots or bowshocks that are ideal for our purposes.
We
will closely mimic many of the earlier exposures using ACS and to
monitor
changes in structures. The morphology and its evolution will be
compared
to 3-D MHD models with adaptive grids in order to build a far
clearer
picture of the nuclear geometry which shaped the outflows and
constrained
their propagation to the present. We shall also obtain R, J,
and
H images for use with a 3-D dust radiative transfer code LELUYA to
model
the dust distribution deep into the nuclear zones.
WFC3/UVI/IR
11570
Narrowing
in on the Hubble Constant and Dark Energy
A
measurement of the Hubble constant to a precision of a few percent
would
be a powerful aid to the investigation of the nature of dark
energy
and a potent "end-to-end" test of the present cosmological model.
In
Cycle 15 we constructed a new, streamlined distance ladder utilizing
high-quality
type Ia supernova data and observations of Cepheids with
HST
in the near-IR to minimize the dominant sources of systematic
uncertainty
in past measurements of the Hubble constant and reduce its
total
uncertainty to a little under 5%. Here we propose to exploit this
new
route to reduce the remaining uncertainty by more than 30%,
translating
into an equal reduction in the uncertainty of the equation
of
state of dark energy. We propose three sets of observations to reach
this
goal: a mosaic of NGC 4258 with WFC3 in F160W to triple its sample
of
long period Cepheids, WFC3/F160W observations of the 6 ideal SN Ia
hosts
to triple their samples of Cepheids, and observations of NGC 5584
the
host of a new SN Ia, SN 2007af, to discover and measure its Cepheids
and
begin expanding the small set of SN Ia luminosity calibrations.
These
observations would provide the bulk of a coordinated program aimed
at
making the measurement of the Hubble constant one of the leading
constraints
on dark energy.
WFC3/UVI
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.
ACS/WFC3
11564
Optical
and Ultraviolet Photometry of Isolated Neutron Stars
We
propose ultraviolet and B-band observations of 5 nearby, thermally
emitting
neutron stars. These data will measure the Rayleigh-Jeans tails
of
their spectra, providing a vital complement to X-ray spectroscopy and
helping
to constrain atmospheric models, working toward the ultimate
goal
of unraveling the physics of neutron stars. With these data we will
have
good-quality optical and UV data for the full sample of these
objects,
allowing detailed comparisons between them. Finally, the data
should
allow us to measure proper motions for one or two objects, and
will
serve as the reference data for the remaining objects; such proper
motions
allow ages to be determined for these objects by tracing them
back
to likely birth locations.
WFC3/UVI/IR
11557
The
Nature of Low-Ionization BAL QSOs
The
rare subclass of optically-selected QSOs known as low-ionization
broad
absorption line (LoBAL) QSOs show signs of high-velocity gas
outflows
and reddened continua indicative of dust obscuration. Recent
studies
show that galaxies hosting LoBAL QSOs tend to be ultraluminous
infrared
systems that are undergoing mergers, and that have dominant
young
(< 100 Myr) stellar populations. Such studies support the idea
that
LoBAL QSOs represent a short- lived phase early in the life of
QSOs,
when powerful AGN-driven winds are blowing away the dust and gas
surrounding
the QSO. If so, understanding LoBALs would be critical in
the
study of phenomena regulating black hole and galaxy evolution, such
as
AGN feedback and the early stages of nuclear accretion. These
results,
however, come from very small samples that may have serious
selection
biases. We are therefore taking a more aggressive approach by
conducting
a systematic multiwavelength study of a volume limited sample
of
LoBAL QSOs at 0.5 < z < 0.6 drawn from SDSS. We propose to image
their
host galaxies in two bands using WFC3/UVIS and WFC3/IR to study
the
morphologies for signs of recent tidal interactions and to map their
interaction
and star forming histories. We will thus determine whether
LoBAL
QSOs are truly exclusively found in young merging systems that are
likely
to be in the early stages of nuclear accretion.
COS
11515
Post-SM4
Cross-Instrument Light Leak Test
This
proposal is based on SMOV Activity COS-37 (SMOV4 Light Leak Test).
This
activity consists of a set of external exposures designed to
determine
whether a particular science instrument (SI) is susceptible to
light
leaks resulting from photons escaping from the calibration system
of
another SI. For the identified combination of SIs (see list below),
the
SI assumed to be the light source will carry out a calibration
activity
while, in parallel, the other SI will perform an external
exposure.
The test is designed to detect gross light leaks that may
affect
science data during typical calibration lamp exposure sequences.
The
test will provide an initial estimate of the amount of contamination
present.
Follow-up observations for cases where light is detected may be
warranted.
The most likely cases for light leaking out of an instrument
will
be configurations with COS as prime when it is in TAGFLASH mode,
with
another SI exposing on the sky in parallel. In TAGFLASH mode, the
COS
external shutter is open and a PtNe wavelength calibration lamp is
flashed
periodically for short intervals (5-30 seconds) during the
science
exposure.
We
use CVZ targeting of regions of sky near the orbit north pole
position
in order to minimize the number of orbits required and the
impact
to the existing SMOV4 timeline. All COS external exposures will
be
centered with the COS primary science aperture on a blank region of
sky.
However, bright object checks will need to be performed by the COS
team
after selection of the final target positions, which depend upon
time
of execution.
This
test is based on the following guidelines:
1)
Check new instruments as source and sink (WFC3 & COS). Check both
WFC3/UVIS
and WFC3/IR. Check COS/FUV only if a problem is seen for
COS/NUV
imaging mode. COS FUV is not currently part of this proposal.
2)
Check known issues (e.g., WFPC2->ACS/WFC and NICMOS->WFPC2, with the
obvious
substitution of WFC3 for WFPC2).
3)
STIS and ACS/SBC will not be used in parallel with COS externals, and
therefore
will not require testing as light sinks. They will not be
checked
as sources either in this proposal.
4)
STIS and ACS/SBC are not likely to be used often with COS internals
and
therefore are not tested in this proposal.
5)
Check ACS/SBC later only if a problem is seen for ACS/HRC (no problem
seen
previously for WFPC2 -> ACS/HRC).
6)
NICMOS is not likely to be used often with COS externals or COS
internals,
and therefore requires testing only with WFC3. However, the
experimental
design allows NICMOS to be tested as a source with COS as
sink.
7)
There are no known problems for axial bay to axial bay cross
contamination
(ACS <-> STIS or ACS <-> NICMOS or STIS <-> NICMOS), so no
problems
are expected for NICMOS <-> COS. The specific combinations of
SIs
to be tested for light leakage and unwanted light detection are as
follows:
1. With the COS External (PtNe TAGFLASH) and Internal (PtNe)
calibration
lamp as the potential source, check for potential detections
by:
ACS/WFC, ACS/HRC, WFC3/UVIS, and WFC3/IR 2. With the WFC3 Internal
(Tungsten)
calibration lamp as a potential source, check for potential
detections
by: ACS/WFC, ACS/HRC, and COS/NUV 3. With the ACS Internal
(Tungsten)
calibration lamp as a potential source, check for potential
detections
by: WFC3/UVIS, WFC3/IR, and COS/NUV 4. With the NICMOS
(Quartz
Halogen) calibration lamp as the potential source, check for
potential
detections by: WFC3/UVIS, WFC3/IR, and COS/NUV
Pre-requisite
proposals that must be executed prior to this proposal
include:
COS-06 NUV Detector Functional ACS-20 UV Sensitivity, Geometric
Distortion
& Flat-field Uniformity ACS-11 HRC Sensitivity, Geometric
Distortion
& Flat-field Stability NIC-04 NICMOS Filter Wheel Test
WFC3-33
UVIS Dark, Read Noise, and Background WFC3-34 IR Dark, Read
Noise,
and Background
COS
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
11475
COS
Internal NUV Wavelength Verification
This
program will be executed after the uplink of the OSM2 position
updates
derived from the determination of the wavelength-scale zero
points
and desired spectral ranges for each grating in activity COS14
(program
11474 - COS NUV 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 NUV ERO observations and NUV science can
be
enabled. An internal wavelength calibration spectrum using the
default
PtNe lamp (lamp 1) with each NUV 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.
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 CAL
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
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.
STIS19
11390
STIS-19
FUV MAMA Dark Measure
The
STIS MAMA HV power supplies are turned on only during each day's
block
of SAA-free orbits. The FUV MAMA dark current glow has been
determined
to increase with the length of time the FUV HV power supply
has
been on. The rate of this daily increase has changed over the years
and
also appears to be sensitive to temperature. To measure the rate at
which
the dark current increases, as soon as possible after the
completion
of STIS-17 (11350) completes a series of five 1380s FUV MAMA
dark
exposures spread over 5 or more orbits of a single SAA period will
be
taken. A second block of five exposures should be done near the end
of
the SMOV period when the temperature of the aft shroud and STIS are
in
the range expected for normal Cycle 17 operations.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
11967
- GSAcq(1,2,1) at 219/18:09:02 resulted in Fine Lock Backup using FGS-1.
Observations possibly affected: ACS 88-91 Proposal ID#
11515,
COS 224-230 Proposal ID# 11515, STIS 87 Proposal ID#
11390,
WFC3 78-79 Proposal ID# 11515.
11970
- GSAcq(1,2,1) at 221/22:06:19 acquired in fine lock backup on FGS
1, scan step limit exceeded on FGS 1 @ 221/2206z.
Observations possibly affected: WFC3 124 - 127, Proposal ID#
11628.
COMPLETED
OPS REQUEST:
18676-0
- Null genslew for proposal 11503 - slot 1 @ 219/1546z
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
26
26
FGS
REAcq
19
19
OBAD
with Maneuver
24
24
SIGNIFICANT
EVENTS: (None)