HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT #4910
PERIOD
COVERED: 5am August 14 - 5am August 17, 2009 (DOY 226/09:00z-229/09:00z)
OBSERVATIONS
SCHEDULED
WFC3/UV
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/UV
11907
UVIS
Cycle 17 Contamination Monitor
The
UV throughput of WFC3 during Cycle 17 is monitored via weekly
standard
star observations in a subset of key filters covering 200-600nm
and
F606W, F814W as controls on the red end. The data will provide a
measure
of throughput levels as a function of time and wavelength,
allowing
for detection of the presence of possible contaminants.
WFC3/UV
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 (11909), will be
used
to generate the necessary superbias and superdark reference files
for
the calibration pipeline (CDBS).
COS/NUV
11896
NUV
Spectroscopic Sensitivity Monitoring
Purpose
is to monitor sensitivity of each NUV grating mode to detect any
change
due to contamination or other causes.
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.
FGS
11789
An
Astrometric Calibration of Population II Distance Indicators
In
2002 HST produced a highly precise parallax for RR Lyrae. That
measurement
resulted in an absolute magnitude, M(V)= 0.61+/-0.11, a
useful
result, judged by the over ten refereed citations each year
since.
It is, however, unsatisfactory to have the direct,
parallax-based,
distance scale of Population II variables based on a
single
star. We propose, therefore, to obtain the parallaxes of four
additional
RR Lyrae stars and two Population II Cepheids, or W Vir
stars.
The Population II Cepheids lie with the RR Lyrae stars on a
common
K-band Period-Luminosity relation. Using these parallaxes to
inform
that relationship, we anticipate a zero-point error of 0.04
magnitude.
This result should greatly strengthen confidence in the
Population
II distance scale and increase our understanding of RR Lyrae
star
and Pop II Cepheid astrophysics.
FGS
11788
The
Architecture of Exoplanetary Systems
Are
all planetary systems coplanar? Concordance cosmogony makes that
prediction.
It is, however, a prediction of extrasolar planetary system
architecture
as yet untested by direct observation for main sequence
stars
other than the Sun. To provide such a test, we propose to carry
out
FGS astrometric studies on four stars hosting seven companions. Our
understanding
of the planet formation process will grow as we match not
only
system architecture, but formed planet mass and true distance from
the
primary with host star characteristics for a wide variety of host
stars
and exoplanet masses.
We
propose that a series of FGS astrometric observations with
demonstrated
1 millisecond of arc per-observation precision can
establish
the degree of coplanarity and component true masses for four
extrasolar
systems: HD 202206 (brown dwarf+planet); HD 128311
(planet+planet),
HD 160691 = mu Arae (planet+planet), and HD 222404AB =
gamma
Cephei (planet+star). In each case the companion is identified as
such
by assuming that the minimum mass is the actual mass. For the last
target,
a known stellar binary system, the companion orbit is stable
only
if coplanar with the AB binary orbit.
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.
STIS/CCD/MA
11690
EG
And: Providing the Missing Link Required for Modelling Red Giant
Mass-loss
For
the majority of red giant stars the basic mass-loss processes at
work
are unknown. Indeed, for stars of spectral types between K0 III and
M5-M6
III, much remains unknown about the regions above the visible
photosphere
and the transportation of the processed material outwards to
the
ISM. Eclipsing symbiotic binary systems, consisting of an evolved
giant
in orbit with a white dwarf, provide an opportunity to take
advantage
of the finite size of the hot component to probe different
levels
of the chromosphere and wind acceleration region in absorption.
This
provides spatially resolved thermal, ionisation and dynamic
information
on the wind which can then be compared against predictions
of
hydrodynamical stellar atmosphere codes. The symbiotic binary EG And
can
be considered as a rosetta stone for understanding the winds of
these
objects. The system is ideal on a number of counts for utilising
the
ultraviolet eclipse of the white dwarf (WD) component to probe,
layer-by-layer,
the thermal and dynamic conditions at the very base of
the
wind and chromosphere of the RG. This information is vital for
constraining,
testing and calibrating the new generation of cool giant
wind+chromosphere
models and is not possible to obtain for isolated RGs.
This
team has studied the UV eclipses of this system in depth and
detail,
however in order to definitively constrain the wind acceleration
profile
and identify the location of the temperature rise just above the
photosphere
we require 4 STIS E140M observations of EG And at specific
orbital
phases. We are also requesting a E230M observation of an
isolated
spectral standard, corresponding to the RG in the binary, which
will
help place the EG And results into the context of the general RG
population
from analysis of the MgII wind diagnostic lines.
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/IR/ACS
11647
A
Deep Exploration of Classes of Long Period Variable Stars in M31
We
propose a thrifty but information-packed investigation with WFC3/IR
F160W
and F110W providing crucial information about Long Period
Variables
in M31, at a level of detail that has recently allowed the
discovery
of new variable star classes in the Magellanic Clouds, a very
different
stellar population. These observations are buttressed by an
extensive
map of the same fields with ACS and WFPC2 exposures in F555W
and
F814W, and a massive ground-based imaging patrol producing
well-sampled
light curves for more than 400, 000 variable stars. Our
primary
goal is to collect sufficient NIR data in order to analyze and
classify
the huge number of long-period variables in our catalog (see
below)
through Period-Luminosity (P/L) diagrams. We will produce
accurate
P/L diagrams for both the bulge and a progression of locations
throughout
the disk of M31. These diagrams will be similar in quality to
those
currently in the Magellanic Clouds, with their lower metallicity,
radically
different star formation history, and larger spread in
distance
to the variables. M31 offers an excellent chance to study more
typical
disk populations, in a manner which might be extended to more
distant
galaxies where such variables are still visible, probing a much
more
evenly spread progenitor age distribution than cepheids (and
perhaps
useful as a distance scale alternative or cross-check). Our data
will
also provide a massive and unique color-magnitude dataset; we
expect
that this study will produce several important results, among
them
a better understanding of P/L and P/L-color relations for pulsating
variables
which are essential to the extragalactic distance ladder. We
will
view these variables at a common distance over a range of
metallicities
(eliminating the distance-error vs. metallicity ambiguity
between
the LMC and SMC), allow further insight into possible
faint-variable
mass-loss for higher metallicities, and in general
produce
a sample more typical of giant disk galaxies predominant in many
studies.
ACS
11603
A
Comprehensive Study of Dust Formation in Type II Supernovae with HST,
Spitzer,
and Gemini
The
recent discovery of three extremely bright Type II SNe, (2007it,
2007oc,
2007od) gives us a unique opportunity to combine observations
with
HST, Spitzer and Gemini to study the little understood dust
formation
process in Type II SNe. Priority 1 Spitzer Cycle 5 and band 1
Gemini
2008A time has already been approved for this project. Since
late-time
Type II SNe are faint and tend to be in crowded fields, we
need
the high sensitivity and high spatial resolution of ACS and
NICMOS/NIC2
for these observations. This project is motivated by the
recent
detection of large amounts of dust in high redshift galaxies. The
dust
in these high-z galaxies must come from young, massive stars so
Type
II SNe could be potential sources. The mechanism and the efficiency
of
dust condensation in Type II SN ejecta are not well understood,
largely
due to the lack of observational data. We plan to produce a
unique
dataset, combining spectroscopy and imaging in the visible, near-
and
mid-IR covering the key phase, 400-700 days after maximum when dust
is
known to form in the SN ejecta. Therefore, we are proposing for
coordinated
HST/NOAO observations (HST ACS, NICMOS/NIC2 & Gemini/GMOS
and
TReCS) which will be combined with our Spitzer Cycle 5 data to study
these
new bright SNe. The results of this program will place strong
constraints
on the formation of dust seen in young high redshift (z>5)
galaxies.
STIS/CCD
11567
Boron
Abundances in Rapidly Rotating Early-B Stars
Models
of rotation in early-B stars predict that rotationally driven
mixing
should deplete surface boron abundances during the main-sequence
lifetime
of many stars. However, recent work has shown that many boron
depleted
stars are intrinsically slow rotators for which models predict
no
depletion should have occurred, while observations of nitrogen in
some
more rapidly rotating stars show less mixing than the models
predict.
Boron can provide unique information on the earliest stages of
mixing
in B stars, but previous surveys have been biased towards
narrow-lined
stars because of the difficulty in measuring boron
abundances
in rapidly rotating stars. The two targets observed as part
of
our Cycle 13 SNAP program 10175, just before STIS failed, demonstrate
that
it is possible to make useful boron abundance measurements for
early-B
stars with Vsin(i) above 100 km/s. We propose to extend that
survey
to a large enough sample of stars to allow statistically
significant
tests of models of rotational mixing in early-B stars.
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.
COS/FUV
11492
FUV
Sensitivity
This
activity confirms COS sensitivity versus wavelength over the entire
observable
spectrum for all FUV gratings and central wavelength
settings.
Obtain quick look sensitivity visit early in SMOV. Later,
after
wavelength calibration is verified, perform a precise-centering
acquisition
and observe an appropriate HST flux standard star (chosen
from
the HST prime standard and FASTEX lists) with the PSA. (A limited
BOA
characterization is obtained in Visit 13 using primary standard
GD153.)
No off aperture- center observations are performed in this
activity
(see COS32, program 11490, for off- center characterizations).
Spectra
will be obtained to meet a Poisson S/N criterion of ~30 per
sensitivity
extraction bin or higher; substantially higher S/N
characterization
will be utilized in routine Cycle 17 calibration.
COS
11486
COS
FUV Target Acquisition Algorithm Verification
Verify
the ability of the COS FSW to place an isolated point source at
the
center of the aperture, both for the BOA and PSA, using dispersed
light
from the object using the FUV gratings. The various options for
target
centering should be exercised and shown to work properly. This
test
is for acquisitions in dispersed-light mode only. This program is
modeled
from SMOV activity summary COS28.
This
program should be executed two or more weeks after visit 12 of
11469,
and after the SIAF update, so that we have confirmed that NUV
imaging
acquisitions work properly with the BOA.
COS
11476
COS
NUV External Spectroscopic Performance - Part 1
The
goal of this project is to measure the spectral resolution of
absorption
lines for each of the four COS NUV gratings. We will acquire
science
data at the central wavelength of each grating through both PSA
and
BOA apertures. We will also evaluate the effect of small pointing
errors
on the spectral resolution by acquiring additional spectra at
spatially
offset positions. The targets chosen for these observations
have
sharp absorption lines and will be either unresolved or marginally
resolved
at the COS resolution.
Our
observations with the PSA will target the subdwarf B star Feige 48
(PG
1144+651). These observations will implement the following
procedure:
First, a target acquisition is performed to place the target
at
the center of the aperture. For each NUV grating we obtain moderately
high
S/N (~ 40 per resel counting statistics) observations at one
central
wavelength setting with the PSA. Next we repeat the sequence of
observations
at each of four additional positions, offset 0.25
arcseconds
from the aperture center to form a diamond pattern. All of
these
observations will be performed in TIME-TAG mode with FLASH=YES,
but
with two differences: First, the summed exposure time for all four
offset
positions is equal to the exposure time of the central position.
Second,
the central position utilizes a four-position FP-split pattern
(FP-POS=AUTO)
while the offset positions are each split into two
sub-exposures,
one with FP-POS=3 and one with FP-POS=1. For one grating
(G185M)
and central wavelength (1850 A) we obtain a TIME-TAG exposure
with
FLASH=NO to verify the auto-wavecal capability of the NUV channel.
The
observations with the BOA will be performed on the bright O subdwarf
BD+75D325,
a bright (M_V = 9.6) HST calibration standard. Here we obtain
a
single TIME-TAG exposure for each of the four NUV gratings with the
object
centered in the BOA to evaluate the spectral resolution in this
mode.
We aim for S/N = 20 in these observations.
The
number of exposures in this program is somewhat larger than the
number
described in the Activity Summary, but is necessary to perform
the
intended
11476( 16) - 20-Mar-2009 11:53:32 - [ 2]
tests
of the COS spectral resolution.
This
activity is SMOV program COS 16.
IMPLEMENTATION
METHOD: Stored Commanding
DATA
REQUIREMENTS: Approximately 420 MB
DEPENDENCIES:
Execute after verification based upon results of activity
COS
15 (Internal NUV Wavelength Calibration)
APPLICABLE
SMOV REQUIREMENTS: L.10.4.2.3.7.2; L.10.4.2.3.13;
L.10.4.2.1.8
COS
11472
COS
NUV Dispersed-light Acquisition Algorithm Verification
Verify
the ability of the COS FSW to place an isolated point source at
the
center of the aperture, both for the BOA and PSA, using dispersed
light
from the object using an NUV grating. The various options for
target
centering should be exercised and shown to work properly.
COS
11471
COS
NUV Imaging Acquisition Algorithm Verification
Verify
the ability of the COS FSW to place an isolated point source at
the
center of the aperture, both for the BOA and PSA, and for MIRRORA
and
MIRRORB. The various options for target centering should be
exercised
and shown to work properly. This test is for acquisitions in
imaging
mode only. Acquisitions using dispersed light are tested in
separate
SMOV activities.
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
11447
WFC3
IR Dark Current, Readnoise, and Background
This
proposal obtains full-frame, four-amp readout images.
Un-illuminated
internals are taken at regularly spaced intervals
throughout
SMOV in order to assess and monitor readnoise and dark
current
(of both light-sensitive pixels and reference pixels), and bad
(warm,
hot, dead, variable) pixels. In addition, externals aimed at
fields
with sparse stellar density are taken to measure diffuse
background
light.
This
program corresponds to WFC3-34.
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.
NIC2
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}.
NIC2/WFPC2
11142
Revealing
the Physical Nature of Infrared Luminous Galaxies at 0.3<z<2.7
Using
HST and Spitzer
We
aim to determine physical properties of IR luminous galaxies at
0.3<z<2.7
by requesting coordinated HST/NIC2 and MIPS 70um observations
of
a unique, 24um flux-limited sample with complete Spitzer mid-IR
spectroscopy.
The 150 sources investigated in this program have S{24um}
>
0.8mJy and their mid-IR spectra have already provided the majority
targets
with spectroscopic redshifts {0.3<z<2.7}. The proposed
150~orbits
of NIC2 and 66~hours of MIPS 70um will provide the physical
measurements
of the light distribution at the rest-frame ~8000A and
better
estimates of the bolometric luminosity. Combining these
parameters
together with the rich suite of spectral diagnostics from the
mid-IR
spectra, we will {1} measure how common mergers are among LIRGs
and
ULIRGs at 0.3<z<2.7, and establish if major mergers are the drivers
of
z>1 ULIRGs, as in the local Universe. {2} study the co-evolution of
star
formation and blackhole accretion by investigating the relations
between
the fraction of starburst/AGN measured from mid-IR spectra vs.
HST
morphologies, L{bol} and z. {3} obtain the current best estimates of
the
far-IR emission, thus L{bol} for this sample, and establish if the
relative
contribution of mid-to-far IR dust emission is correlated with
morphology
{resolved vs. unresolved}.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
11979
- Loss of lock on FGS 1 occurred at 18:07:39 with recovery at
226/18:08:49. FGS 2 lost lock at 226/18:07:48 and recovered
at 226/18:08:15.
Observations affected: COS 57 - 61, Proposal ID# 11472.
11982
- GSAcq(2,3,3)at 228/14:20:10 failed due to search radius limit
exceeded(SRLEX) on FGS 2 and FGS 3.
Observations affected: ACS 59 - 62 Proposal ID# 11647,
WFC3 109 Proposal
ID# 11647.
11984
- GSAcq(2,1,1) scheduled at 229/05:23:31 - 05:31:02 failed to RGA
Hold (gyro control) due to search radius limit exceeded on FGS-2.
Observations affected: WFC3 5,6 Proposal ID#
11905,
STIS 1
Proposal ID# 11567.
COMPLETED
OPS REQUEST:
18685-0
- Null genslews for proposal 11492 - slots 1 and 2 @ 226/16:30z
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL FAILURE TIMES
FGS
GSAcq
21
19
FGS
REAcq
21
21
OBAD
with Maneuver
23
23
LOSS
of LOCK
226/18:07:39z
SIGNIFICANT
EVENTS: (None)