HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5142
PERIOD
COVERED: 5am July 20 - 5am July 21, 2010 (DOY 201/09:00z-202/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
From DOY
188:
#12336
GSAcq(2,1,1) @188/14:11:27z required two attempts to achieve
CT-DV on FGS2. The acquisition was successful.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq
5
5
FGS
REAcq
11
11
OBAD with
Maneuver
6
6
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC3
11833
Monitoring
M31 for BHXNe
During
A01-8 we found ~20 Black Hole X-ray Novae (BHXNe) in M31 using
Chandra, and
with HST follow-up have estimated orbital periods for 8 of
these.
Observations are underway with HST to attempt to estimate
additional
periods. We propose to continue this program concentrating
our scarce
HST resources on a single transient which exceeds 1e38 erg/s.
Only
uninterrupted monitoring can yield the duty cycles and long-term
light
curves of BHXNe (and other variables) in M31. Our GO+GTO programs
will have
accumulated 790ks (ACIS+HRC) near the M31 bulge by the end of
AO9, and
total Chandra exposure on M31 is now 940ks. By continuing our
monitoring
program through AO12 we will reach ~950ks on the bulge and
>1Msec
total Chandra M31 exposure.
COS/FUV
11527
COS-GTO: An
Absorption Study of Galactic Intermediate Velocity Clouds
Using Hot
Stars in Globular Clusters
We shall
use UV bright hot post-AGB stars located within the globular
clusters of
NGC 5139, NGC 6752, NGC 7078, NGC 6205, NGC 5272 and NGC
1904 to
sample the UV absorption properties of the intervening
line-of-sight
interstellar gas. Such sight-lines pass through several
intermediate
velocity clouds (IVC?s) thought to be located within 5 kpc
of our
Galaxy, thus allowing the physical and chemical state of this gas
to be
probed and compared with the properties of interstellar gas
located in
the galactic disk. Elemental abundances of the IVC gas shall
be derived
in order to determine a possible origin for these in-falling
galactic
satellite cloud structures.
COS/FUV
11686
The Cosmological
Impact of AGN Outflows: Measuring Absolute Abundances
and Kinetic
Luminosities
AGN
outflows are increasingly invoked as a major contributor to the
formation
and evolution of supermassive black holes, their host
galaxies,
the surrounding IGM, and cluster cooling flows. Our HST/COS
proposal
will determine reliable absolute chemical abundances in six AGN
outflows,
which influences several of the processes mentioned above. To
date there
is only one such determination, done by our team on Mrk 279
using 16
HST/STIS orbits and 100 ksec of FUSE time. The advent of COS
and its
high sensitivity allows us to choose among fainter objects at
redshifts
high enough to preclude the need for FUSE. This will allow us
to
determine the absolute abundances for six AGN (all fainter than Mrk
279) using
only 40 HST COS orbits. This will put abundances studies in
AGN on a
firm footing, an elusive goal for the past four decades. In
addition,
prior FUSE observations of four of these targets indicate that
it is
probable that the COS observations will detect troughs from
excited
levels of C III. These will allow us to measure the distances of
the
outflows and thereby determine their kinetic luminosity, a major
goal in AGN
feedback research.
We will use
our state of the art column density extraction methods and
velocity-dependent
photoionization models to determine the abundances
and kinetic
luminosity. Previous AGN outflow projects suffered from the
constraints
of deciding what science we could do using ONE of the
handful of
bright targets that were observable. With COS we can choose
the best
sample for our experiment. As an added bonus, most of the
spectral
range of our targets has not been observed previously, greatly
increasing
the discovery phase space.
STIS/CC
11845
CCD Dark
Monitor Part 2
Monitor the
darks for the STIS CCD.
STIS/CC
11847
CCD Bias
Monitor-Part 2
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
11721
Verifying
the Utility of Type Ia Supernovae as Cosmological Probes:
Evolution
and Dispersion in the Ultraviolet Spectra
The study
of distant type Ia supernova (SNe Ia) offers the most
practical
and immediate discriminator between popular models of dark
energy. Yet
fundamental questions remain over possible
redshift-dependent
trends in their observed and intrinsic properties.
High-quality
Keck spectroscopy of a representative sample of 36
intermediate
redshift SNe Ia has revealed a surprising, and unexplained,
diversity
in their rest-frame UV fluxes. One possible explanation is
hitherto
undiscovered variations in the progenitor metallicity.
Unfortunately,
this result cannot be compared to local UV data as only
two
representative SNe Ia have been studied near maximum light. Taking
advantage
of two new `rolling searches' and the restoration of STIS, we
propose a
non-disruptive TOO campaign to create an equivalent comparison
local
sample. This will allow us to address possible evolution in the
mean UV
spectrum and its diversity, an essential precursor to the study
of SNe
beyond z~1.
WFC3/IR
11712
Calibration
of Surface Brightness Fluctuations for WFC3/IR
We aim to
characterize galaxy surface brightness fluctuations (SBF), and
calibrate
the SBF distance method, in the F110W and F160W filters of the
Wide Field
Camera 3 IR channel. Because of the very high throughput of
F110W and
the good match of F160W to the standard H band, we anticipate
that both
of these filters will be popular choices for galaxy
observations
with WFC3/IR. The SBF signal is typically an order of
magnitude
brighter in the near-IR than in the optical, and the
characteristics
(sensitivity, FOV, cosmetics) of the WFC3/IR channel
will be
enormously more efficient for SBF measurements than previously
available
near-IR cameras. As a result, our proposed SBF calibration
will allow
accurate distance derivation whenever an early-type or
bulge-dominated
galaxy is observed out to a distance of 150 Mpc or more
(i.e., out
to the Hubble flow) in the calibrated passbands. For
individual
galaxy observations, an accurate distance is useful for
establishing
absolute luminosities, black hole masses, linear sizes,
etc.
Eventually, once a large number of galaxies have been observed
across the
sky with WFC3/IR, this SBF calibration will enable accurate
mapping of
the total mass density distribution in the local universe
using the
data available in the HST archive. The proposed observations
will have
additional important scientific value; in particular, we
highlight
their usefulness for understanding the nature of multimodal
globular
cluster color distributions in giant elliptical galaxies.
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
11697
Proper
Motion Survey of Classical and SDSS Local Group Dwarf Galaxies
Using the
superior resolution of HST, we propose to continue our proper
motion survey
of Galactic dwarf galaxies. The target galaxies include
one
classical dwarf, Leo II, and six that were recently identified in
the Sloan
Digital Sky Survey data: Bootes I, Canes Venatici I, Canes
Venatici
II, Coma Berenices, Leo IV, and Ursa Major II. We will observe
a total of
16 fields, each centered on a spectroscopically-confirmed
QSO. Using
QSOs as standards of rest in measuring absolute proper
motions has
proven to be the most accurate and most efficient method.
HST is our
only option to quickly determine the space motions of the
SDSS dwarfs
because suitable ground-based imaging is only a few years
old and
such data need several decades to produce a proper motion. The
two most
distant galaxies in our sample will require time baselines of
four years
to achieve our goal of a 30-50 km/s uncertainty in the
tangential
velocity; given this and the finite lifetime of HST, it is
imperative
that first-epoch observations be taken in this cycle. The
SDSS dwarfs
have dramatically lower surface brightnesses and
luminosities
than the classical dwarfs. Proper motions are crucial for
determining
orbits of the galaxies and knowing the orbits will allow us
to test
theories for the formation and evolution of these galaxies and,
more
generally, for the formation of the Local Group.
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).
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/UVIS/IR
11909
UVIS Hot
Pixel Anneal
The
on-orbit radiation environment of WFC3 will continually generate new
hot pixels.
This proposal performs the procedure required for repairing
those hot
pixels in the UVIS CCDs. During an anneal, the two-stage
thermo-electric
cooler (TEC) is turned off and the four-stage TEC is
used as a
heater to bring the UVIS CCDs up to ~20 deg. C. As a result of
the CCD
warmup, a majority of the hot pixels will be fixed; previous
instruments
such as WFPC2 and ACS have seen repair rates of about 80%.
Internal
UVIS exposures are taken before and after each anneal, to allow
an
assessment of the procedure's effectiveness in WFC3, provide a check
of bias,
global dark current, and hot pixel levels, as well as support
hysteresis
(bowtie) monitoring and CDBS reference file generation. One
IR dark is
taken after each anneal, to provide a check of the IR
detector.
-Lynn
NASA
office: 301-286-2876
__________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations Manager
CHAMP Flight Operations Team Manager
Lockheed Martin Mission Services (LMMS)
"...Hubble is the most significant
science instrument of all time in terms of its productivity..."
Scott Altman @12:45pm 5/21/9 STS-125 Senate
Subcommittee Hearing