HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #4940
PERIOD
COVERED: 5am September 28 - 5am September 29, 2009 (DOY 271/09:00z-272/09:00z)
OBSERVATIONS
SCHEDULED
ACS/WFC3
11713
The
Light Echoes Around V838 Monocerotis
V838
Monocerotis, which burst upon the astronomical scene in early 2002,
is
a completely unanticipated new object. It underwent a large-amplitude
and
very luminous outburst, during which its spectrum remained that of
an
extremely cool supergiant. A rapidly evolving set of light echoes
around
V838 Mon was discovered soon after the outburst, and quickly
became
the most spectacular display of the phenomenon yet seen. These
light
echoes provide the means to accomplish three unique types of
measurements
based on continued HST imaging during the event: (1) Study
effects
of MHD turbulence at high resolution and in 3 dimensions; (2)
Construct
the first unambiguous and fully 3-D map of a circumstellar
dust
envelope in the Milky Way; (3) Study dust physics in a unique
setting
where the spectrum and light curve of the illumination, and the
scattering
angle, are unambiguously known. We have also used our HST
data
to determine the distance to V838 Mon through a novel direct
geometric
technique.
Because
of the extreme rarity of light echoes, this is almost certainly
the
only opportunity to achieve such results during the lifetime of HST.
We
propose two visits during Cycle 17, using the repaired ACS (or WFC3)
in
order to continue the mapping of the circumstellar dust and to
accomplish
the other goals listed above.
ACS/WFC3
11879
CCD
Daily Monitor (Part 1)
This
program comprises basic tests for measuring the read noise and dark
current
of the ACS WFC and for tracking the growth of hot pixels. The
recorded
frames are used to create bias and dark reference images for
science
data reduction and calibration. This program will be executed
four
days per week (Mon, Wed, Fri, Sun) for the duration of Cycle 17. To
facilitate
scheduling, this program is split into three proposals. This
proposal
covers 352 orbits (22 weeks) from 31 August 2009 to 31 January
2010.
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.
COS/FUV
11895
FUV
Detector Dark Monitor
The
purpose of this proposal is to monitor the FUV detector dark rate by
taking
long science exposures without illuminating the detector. The
detector
dark rate and spatial distribution of counts will be compared
to
pre-launch and SMOV data in order to verify the nominal operation of
the
detector. Variations of count rate as a function of orbital position
will
be analyzed to find dependence of dark rate on proximity to the
SAA.
Dependence of dark rate as function of time will also be tracked.
COS/NUV
11894
NUV
Detector Dark Monitor
The
purpose of this proposal is to 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 and SMOV data in order to verify the nominal operation of
the
detector. Variations of count rate as a function of orbital position
will
be analyzed to find dependence of dark rate on proximity to the
SAA.
Dependence of dark rate as function of time will also be tracked.
NIC1/NIC2/NIC3
11947
Extended
Dark Monitoring
This
program takes a series of darks to obtain darks (including
amplifier
glow, dark current, and shading profiles) for all three
cameras
in the read-out sequences used in Cycle 17. A set of 12 orbits
will
be observed every two months for a total of 72 orbits for a 12
month
Cycle 17. This is a continuation of Cycle 16 program 11330 scaled
down
by ~80%.
The
first orbit (Visit A0) should be scheduled in the NICMOS SMOV after
the
DC Transfer Test (11406) and at least 36h before the Filter Wheel
Test
(11407). Data download using fast track.
The
following 28 orbits (visit A1-N2) should be scheduled AFTER the SMOV
Proposal
11407 (Filter Wheel Test). This is done in order to monitor the
dark
current following an adjustment of the NCS set-point. These visits
should
be executed until the final temperature is reached during SMOV.
NIC1/NIC2/NIC3
8795
NICMOS
Post-SAA Calibration - CR Persistence Part 6
This
is a new procedure proposed to alleviate the CR-persistence problem
of
NICMOS. Dark frames will be obtained immediately upon exiting the SAA
contour
23, and every time a NICMOS exposure is scheduled within 50
minutes
of coming out of the SAA. The darks will be obtained in parallel
in
all three NICMOS cameras. The post-SAA darks will be non-standard
reference
files available to users with a 'Use After' date/time mark.
The
keyword 'UseAfter=date/time' will also be added to the header of
each
post-SAA dark frame. The keyword must be populated with the time,
in
addition to the date, because HST crosses the SAA ~8 times per day,
so
each post-SAA dark will need to have the appropriate time specified,
for
users to identify the ones they need. Both the raw and processed
images
will be archived as post-SAA darks. Generally we expect that all
NICMOS
science/calibration observations started within 50 minutes of
leaving
an SAA will need such MAPs to remove the CR persistence from the
science
images. Each observation will need its own CRMAP, as different
SAA
passages leave different imprints on the NICMOS detectors.
STIS/CCD
11844
CCD
Dark Monitor Part 1
The
purpose of this proposal is to monitor the darks for the STIS CCD.
STIS/CCD
11846
CCD
Bias Monitor-Part 1
The
purpose of this proposal is to 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
11855
STIS/CCD
Spectroscopic Sensitivity Monitor for Cycle 17
The
purpose of this proposal is to monitor the sensitivity of each CCD
grating
mode to detect any changes due to contamination or other causes.
STIS/CCD/FGS
11848
CCD
Read Noise Monitor
This
proposal measures the read noise of all the amplifiers (A, B, C, D)
on
the STIS CCD using pairs of bias frames. Full-frame and binned
observations
are made in both Gain 1 and Gain 4, with binning factors of
1x1,
1x2, 2x1, and 2x2. All exposures are internals. Pairs of visits are
scheduled
monthly for the first four months and then bi-monthly after
that.
STIS/CCD/MA1/MA2
11860
MAMA
Spectroscopic Sensitivity and Focus Monitor
The
purpose of this proposal is to monitor the sensitivity of each MAMA
grating
mode to detect any change due to contamination or other causes,
and
to also monitor the STIS focus in a spectroscopic and an imaging
mode.
WFC3/ACS/UVIS
11613
GHOSTS:
Stellar Outskirts of Massive Spiral Galaxies
We
propose to continue our highly successful GHOSTS HST survey of the
resolved
stellar populations of nearby, massive disk galaxies using
SNAPs.
These observations provide star counts and color-magnitude
diagrams
2-3 magnitudes below the tip of the Red Giant Branch of the
outer
disk and halo of each galaxy. We will measure the metallicity
distribution
functions and stellar density profiles from star counts
down
to very low average surface brightnesses, equivalent to ~32 V-mag
per
square arcsec.
This
proposal will substantially improve our unique sampling of galaxy
outskirts.
Our targets cover a range in galaxy mass, luminosity,
inclination,
and morphology. As a function of these galaxy properties,
this
survey provides: - the most extensive, systematic measurement of
radial
light profiles and axial ratios of the diffuse stellar halos and
outer
disks of spiral galaxies; - a comprehensive analysis of halo
metallicity
distributions as function of galaxy type and position within
the
galaxy; - an unprecedented study of the stellar metallicity and age
distribution
in the outer disk regions where the disk truncations occur;
-
the first comparative study of globular clusters and their field
stellar
populations.
We
will use these fossil records of the galaxy assembly process to test
halo
formation models within the hierarchical galaxy formation scheme.
WFC3/IR
11108
Near
Infrared Observations of a Sample of z~6.5-6.7 Galaxies
The
majority of the most distant galaxies discovered to date have been
found
by strong Lyman alpha emission at red optical wavelengths. An
accurate
estimate of the star formation rates for these objects requires
a
measurement of the line-free UV continuum, which must be taken at
infrared
wavelengths. Here we propose to obtain imaging with WFC3 in the
F140W
filter for a sample of 9 Lyman alpha galaxies with redshifts z~6.5
up
to z=6.740 from a complete, flux-limited widefield narrowband and
multi-color
survey conducted on the 8-m Subaru Telescope. This program
will
investigate galaxy morphologies and star formation for a uniform
sample
of the highest redshift galaxies now known.
WFC3/IR
11208
The
Co-Evolution of Spheroids and Black Holes in the Last Six Billion
Years
The
masses of giant black holes are correlated with the luminosities,
masses,
and velocity dispersions of the bulges of their host galaxies.
This
empirical correlation of phenomena on widely different scales (from
pcs
to kpcs) suggests that the formation and evolution of galaxies and
central
black holes are closely linked. In Cycle 13, we have started a
campaign
to map directly the co-evolution of spheroids and black-holes
by
measuring in observationally favorable redshift windows the empirical
correlations
connecting their properties. By focusing on Seyfert 1s,
where
the nucleus and the stars contribute comparable fractions of total
light,
black hole mass and bulge dispersion are obtained from Keck
spectroscopy.
HST is required for accurate measurement of the non-
stellar
AGN continuum, the morphology of the galaxy, and the structural
parameters
of the bulge. The results at z=0.36 indicate a surprisingly
fast
evolution of bulges in the past 4 Gyrs (significant at the 95%CL),
in
the sense that bulges were significantly smaller for a given black
hole
mass. Also, the large fraction of mergers and disturbed galaxies
(4+2
out of 20) identifies gas-rich mergers as the mechanisms
responsible
for bulge- growth. Going to higher redshift - where
evolutionary
trends should be stronger - is needed to confirm these
tantalizing
results. We propose therefore to push our investigation to
the
next suitable redshift window z=0.57 (lookback-time 6 Gyrs). Fifteen
objects
are the minimum number required to map the evolution of the
empirical
correlations between bulge properties and black-hole mass, and
to
achieve a conclusive detection of evolution (>99%CL).
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
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.
WFC3/UVIS
11594
A
WFC3 Grism Survey for Lyman Limit Absorption at z=2
We
propose to conduct a spectroscopic survey of Lyman limit absorbers at
redshifts
1.8 < z < 2.5, using WFC3 and the G280 grism. This proposal
intends
to complete an approved Cycle 15 SNAP program (10878), which was
cut
short due to the ACS failure. We have selected 64 quasars at 2.3 < z
<
2.6 from the Sloan Digital Sky Survey Spectroscopic Quasar Sample, for
which
no BAL signature is found at the QSO redshift and no strong metal
absorption
lines are present at z > 2.3 along the lines of sight. The
survey
has three main observational goals. First, we will determine the
redshift
frequency dn/dz of the LLS over the column density range 16.0 <
log(NHI)
< 20.3 cm^-2. Second, we will measure the column density
frequency
distribution f(N) for the partial Lyman limit systems (PLLS)
over
the column density range 16.0 < log(NHI) < 17.5 cm^-2. Third, we
will
identify those sightlines which could provide a measurement of the
primordial
D/H ratio. By carrying out this survey, we can also help
place
meaningful constraints on two key quantities of cosmological
relevance.
First, we will estimate the amount of metals in the LLS using
the
f(N), and ground based observations of metal line transitions.
Second,
by determining f(N) of the PLLS, we can constrain the amplitude
of
the ionizing UV background at z~2 to a greater precision. This survey
is
ideal for a snapshot observing program, because the on-object
integration
times are all well below 30 minutes, and follow-up
observations
from the ground require minimal telescope time due to the
QSO
sample being bright.
WFC3/UVIS
11903
UVIS
Photometric Zero Points
This
proposal obtains the photometric zero points in 53 of the 62
UVIS/WFC3
filters: the 18 broad-band filters, 8 medium-band filters, 16
narrow-band
filters, and 11 of the 20 quad filters (those being used in
cycle
17). The observations will be primary obtained by observing the
hot
DA white dwarf standards GD153 and G191-B2B. A redder secondary
standard,
P330E, will be observed in a subset of the filters to provide
color
corrections. Repeat observations in 16 of the most widely used
cycle
17 filters will be obtained once per month for the first three
months,
and then once every second month for the duration of cycle 17,
alternating
and depending on target availability. These observations
will
enable monitoring of the stability of the photometric system.
Photometric
transformation equations will be calculated by comparing the
photometry
of stars in two globular clusters, 47 Tuc and NGC 2419, to
previous
measurements with other telescopes/instruments.
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.
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.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12025
- REAcq(1,2,1) scheduled at 272/03:26:54z acquired fine lock after four
attempts, causing the take data flag to come up late.
Observations possibly affected: COS 17 -20, Proposal ID# 11896.
- REAcq(1,2,1) scheduled at 272/04:04:29 failed to
acquire lock after four
attempts
Observations affected: WFC3 31, Proposal ID# 11905; and WFC3 32-34,
Proposal ID# 11929.
12026
- GSAcq(2,1,1) scheduled for 272/06:42:25z failed due to search radius
exceeded on FGS2.
Observation affected: WFC3 35, Proposal ID# 11565.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSAcq 10
09
FGS
REAcq 10
09
OBAD
with Maneuver
09 09
SIGNIFICANT
EVENTS: (None)