HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5130
PERIOD
COVERED: 5am July 1 - 5am July 2, 2010 (DOY 182/09:00z-183/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
(None)
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq
4
4
FGS
REAcq
12
12
OBAD with
Maneuver
4
4
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC3
11586
Exceptional
Galactic Halo Globular Clusters and the Second Parameter
We propose
to obtain deep ACS-WFC images of six globular clusters (five
of which
have no previous HST photometry) that reside in the Galactic
halo, where
the second parameter effect is most pronounced. These
globular
clusters are among the least studied in the Galaxy and yet,
from the
perspective of the second parameter phenomenon, the most
intriguing.
With the
best available CMDs only reaching the vicinity of the main
sequence
turn off at present, the unique sensitivity and resolution of
ACS-WFC
will yield ages of unprecedented precision for these clusters.
These data
will provide us with new insight into the stellar populations
present in
the outer Galactic halo and the nature of the second
parameter.
The second parameter plays a critical role in our
understanding
of the formation and evolution of the Galaxy and the
proposed
observations will shed new light on this problem and these
exceptional
clusters.
COS/NUV/FUV
11659
Probing the
Interior of SN1006
The remnant
of SN 1006 is unique among all supernova remnants in having
3
identified background UV sources that can be used to probe cold,
otherwise
unseen ejecta within the remnant shell. We propose
high-resolution
spectra from COS to obtain spectra of all three of
these. The
brightest of these, the Schweizer-Middleditch star (the only
one with
extensive previous high-quality UV spectra) shows Si II
absorption with
an extremely unusual asymmetric profile with a sharp
edge on the
red end, indicating the velocity of material just entering
the reverse
shock. Our new spectrum can be compared with STIS
observations
from 1999 to measure definitively the velocity change as
the reverse
shock eats its way into ever-more- slowly-expanding ejecta.
One may
well ask, however, if this profile is truly representative, and
we seek to
answer that with a spectrum of a background quasar at a
similar
distance of the SM star from the projected center, but in a
different
direction. And by investigating the detailed structure of
these two
sources and a second quasar, we can probe small-scale
structure
in the ejecta. No object other than SN1006 offers a similar
opportunity
to probe the distribution of ejecta within the remnant of a
Type Ia
supernova.
S/C 12046
COS FUV DCE
Memory Dump
Whenever
the FUV detector high voltage is on, count rate and current
draw
information is collected, monitored, and saved to DCE memory. Every
10 msec the
detector samples the currents from the HV power supplies
(HVIA,
HVIB) and the AUX power supply (AUXI). The last 1000 samples are
saved in
memory, along with a histogram of the number of occurrences of
each
current value.
In the case
of a HV transient (known as a "crackle" on FUSE), where one
of these
currents exceeds a preset threshold for a persistence time, the
HV will
shut down, and the DCE memory will be dumped and examined as
part of the
recovery procedure. However, if the current exceeds the
threshold
for less than the persistence time (a "mini-crackle" in FUSE
parlance),
there is no way to know without dumping DCE memory. By
dumping and
examining the histograms regularly, we will be able to
monitor any
changes in the rate of "mini-crackles" and thus learn
something
about the state of the detector.
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/MA1/MA2
11839
The Cycles
of Alpha Centauri
This is the
HST part of a joint Chandra/HST observing program. The
objective
of the HST part is to obtain new UV spectra of both components
of the
Alpha Centauri binary: the primary ("Alpha Cen A") is a near twin
of the Sun,
while the companion ("B") is an early K dwarf, slightly less
massive,
smaller and less luminous than the Sun. The orbital period is
80 yr, and
the two stars currently are separated by about 8". The Alpha
Cen system
has been the subject of long term coronal X-ray monitoring by
four
successive generations of space observatories, and extensive UV
measurements
were obtained periodically during the IUE era, from the
late 1970's
to late 1990's. The present program will obtain new STIS
echelle
spectra of both stars, which each were observed in selected
wavelength
windows by GHRS in the mid-1990's, and Alpha Cen A later by
STIS in an
extensive high-res program in 1999, although B unfortunately
never was
recorded by STIS.
WFC3/IR
11631
Binary
Brown Dwarfs and the L/T Transition
Brown
dwarfs traverse spectral types M, L and T as their atmospheric
structure
evolves and they cool into oblivion. This SNAPSHOT program
will obtain
WFC3-IR images of 45 nearby late-L and early-T dwarfs to
investigate
the nature of the L/T transition. Recent analyses have
suggested
that a substantial proportion of late-L and early-T dwarfs are
binaries,
comprised of an L dwarf primary and T dwarf secondary. WFC3-IR
observations
will let us quantify this suggestion by expanding coverage
to a much
larger sample, and permitting comparison of the L/T binary
fraction
against ‘normal’ ultracool dwarfs. Only eight L/T binaries are
currently
known, including several that are poorly resolved: we
anticipate
at least doubling the number of resolved systems. The
photometric
characteristics of additional resolved systems will be
crucial to
constraining theoretical models of these late-type ultracool
dwarfs.
Finally, our data will also be eminently suited to searching for
extremely
low luminosity companions, potentially even reaching the Y
dwarf
regime.
WFC3/IR
11648
WFC3
Spectroscopy of an X-ray Luminous Galaxy Cluster at z>2
We propose
to obtain deep WFC3+G141 grism observations to
spectroscopically
confirm a remarkable z>2 cluster of galaxy candidate.
Over a 1000
arcmin^2 field imaged with Spitzer's IRAC we have discovered
a compact
(<30ÕÕ diameter) concentration of extremely red galaxies with
a factor of
>40 overdensity over the adjacent field. Among these
galaxies
for which we can derive meaningful photometric redshifts, 17
are
consistent with zphot=2-2.5, making it very likely that the
concentration
is a real cluster at such high redshift. This is further
supported
by a 3.5 sigma detection of extended X-Ray emission on
XMM-Newton
data, by a likely color magnitude sequence of red galaxies,
and by the
presence of a giant galaxy consistent with a BCG at the
cluster
redshift. The general faintness of the red galaxies in all
optical
bands and their high redshifts prevent confirmation of this
cluster
with ordinary optical spectroscopy. The WFC3 camera with G141
grism
provides the only way to confirm this record high-z cluster and
measure its
redshift from spectral breaks typical of old stellar
populations.
Our deep integrations will reveal redshifts for at least 19
ultra-red
galaxies in the area and of a similar number of bluer galaxies
at the
cluster redshift. Knowledge of the cluster redshift based on the
HST spectra
will allow us to reach important scientific aims: find the
most
distant Xray emitting evolved galaxy cluster, determine membership
of the
other galaxies from photometric SED analysis, study their stellar
population
properties, characterize the color-magnitude relation with
constraints
on the formation redshift. The proposed observations will
establish a
first z>2 benchmark for cluster field comparisons of galaxy
formation at
this highest redshift and will firmly establish the
progenitors
of local rich Abell clusters.
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
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
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.
-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