HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5172
PERIOD
COVERED: 5am August 31 - 5am September 1, 2010 (DOY 243/09:00z-244/09:00z)
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
12372
- GSAcq(2,1,1) at 244/06:14:12z and REAcq(2,1,1) at 244/07:45:09z
both acquired fine lock backup on FGS 2.
Observations possibly affected WFC3 77-81, Proposal ID#11729.
FOR
DOY 228:
12370
- REAcq(1,2,1) at 228/06:33:05z required two attempts to achieve
FL-DV on FGS1. The acquisition was successful.
Observations possibly affected: ACS 12 Proposal ID#11996 and
STIS 6 Proposal ID#11668.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED SUCCESSFUL
FGS
GSAcq
10
10
FGS
REAcq
08
08
OBAD
with Maneuver
08
08
SIGNIFICANT
EVENTS: (None)
OBSERVATIONS
SCHEDULED:
ACS/WFC
11996
CCD
Daily Monitor (Part 3)
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 308 orbits (19.25 weeks) from 21 June 2010 to 1 November
2010.
WFC3/UVIS
11729
Photometric
Metallicity Calibration with WFC3 Specialty Filters
The
community has chosen to include several filters in the WFC3 filter
complement
that have been designed to allow fairly precise estimates of
stellar
metallicities, and many science programs are enabled by this
capability.
Since these filters do not exactly match those used for this
purpose
on the ground, however, the mapping of stellar colors to stellar
metallicities
needs to be calibrated. We propose to achieve this
calibration
through observations of five stellar clusters with well
known
metallicities. We will calibrate several different filter
calibrations
which will allow future users to determine what filter
combination
best meets their science needs.
STIS/CC/MA
11668
Cosmo-chronometry
and Elemental Abundance Distribution of the Ancient
Star
HE1523-0901
We
propose to obtain near-UV HST/STIS spectroscopy of the extremely
metal-poor,
highly r-process-enhanced halo star HE 1523-0901, in order
to
produce the most complete abundance distribution of the heaviest
stable
elements, including platinum, osmium, and lead. These HST
abundance
data will then be used to estimate the initial abundances of
the
long-lived radioactive elements thorium and uranium, and by
comparison
with their observed abundances, enable an accurate age
determination
of this ancient star. The use of radioactive chronometers
in
stars provides an independent lower limit on the age of the Galaxy,
which
can be compared with alternative limits set by globular clusters
and
by analysis from WMAP. Our proposed observations of HE1523-0901 will
also
provide significant new information about the early chemical
history
of the Galaxy, specifically, the nature of the first generations
of
stars and the types of nucleosynthetic processes that occurred at the
onset
of Galactic chemical evolution.
ACS/WFC3
11604
The
Nuclear Structure of OH Megamaser Galaxies
We
propose a snapshot survey of a complete sample of 80 OH megamaser
galaxies.
Each galaxy will be imaged with the ACS/WFC through F814W and
a
linear ramp filter (FR656N or FR716N or FR782N or FR853N) allowing us
to
study both the spheroid and the gas morphology in Halpha + [N II]. We
will
use the 9% ramps FR647M (5370-7570 angstroms) centered at 7000
angstroms
and FR914M (7570-10, 719 angstroms) 8000 angstroms for
continuum
subtraction for the high and low z objects respectively. OH
megamaser
galaxies (OHMG) form an important class of ultraluminous
IR-galaxies
(ULIRGs) whose maser lines emit QSO-like luminosities.
ULIRGs
in general are associated with recent mergers but it is often
unclear
whether their power output is dominated by starbursts or a
hidden
QSO because of the high absorbing columns which hide their nuclei
even
at X-ray wavelengths. In contrast, OHMG exhibit strong evidence for
the
presence of an energetically important and recently triggered active
nucleus.
In particular it is clear that much of the gas must have
already
collapsed to form a nuclear disk which may be the progenitor of
a
circum-nuclear torus, a key element of the unified scheme of AGN. A
great
advantage of studying OHMG systems over the general ULIRG
population,
is that the circum-nuclear disks are effectively "fixed" at
an
inner, edge on, orientation, eliminating varying inclination as a
nuisance
parameter. We will use the HST observations in conjunction with
existing
maser and spectroscopic data to construct a detailed picture of
the
circum-nuclear regions of a hitherto relatively neglected class of
galaxy
that may hold the key to understanding the relationship between
galaxy
mergers, nuclear star- formation, and the growth of massive black
holes
and the triggering of nuclear activity.
COS/NUV
11540
COS-GTO:
Search for Hydrocarbons and Nitriles in Pluto's Atmosphere
Methane
is highly abundant in Pluto's atmosphere, and methane photolysis
is
the starting point for a series of chemical processes that should
result
in the production of hydrocarbons and nitriles. Photochemical
modeling
of Pluto's atmosphere has suggested that detectable abundances
of
various hydrocarbons and nitriles should occur on Pluto. However,
past
analysis of 40 orbits of archival HST/FOS data in the mid-UV has
only
produced upper limits on abundances of C4H2, C6H2, HC3N, and C4N2.
We
will use COS to obtain spectra from 2060-2460A, including absorption
bands
of the hydrocarbon diacetylene (C4H2) and the nitrile
cyanoacetylene
(HC3N). Previously-measured 2-sigma upper limits for
these
compounds are somewhat below the values computed in the
poorly-constrained
models; the measurement uncertainties themselves are
of
the same order as the modeled values. By reducing the uncertainties
by
a factor of a few to several, we aim to detect the presence of these
compounds,
or to provide more restrictive abundance limits. These
measurements
will provide valuable new data on the nature and chemistry
of
the Plutonian atmosphere.
STIS/CCD
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
STIS/CCD
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/MA2
11862
MAMA
NUV Flats
This
program will obtain NUV-MAMA observations of the STIS internal
Deuterium
lamp to construct an NUV flat applicable to all NUV modes.
WFC3/ACS/IR
11563
Galaxies
at z~7-10 in the Reionization Epoch: Luminosity Functions to
<0.2L*
from Deep IR Imaging of the HUDF and HUDF05 Fields
The
first generations of galaxies were assembled around redshifts
z~7-10+,
just 500-800 Myr after recombination, in the heart of the
reionization
of the universe. We know very little about galaxies in this
period.
Despite great effort with HST and other telescopes, less than
~15
galaxies have been reliably detected so far at z>7, contrasting with
the
~1000 galaxies detected to date at z~6, just 200-400 Myr later, near
the
end of the reionization epoch. WFC3 IR can dramatically change this
situation,
enabling derivation of the galaxy luminosity function and its
shape
at z~7-8 to well below L*, measurement of the UV luminosity
density
at z~7-8 and z~8-9, and estimates of the contribution of
galaxies
to reionization at these epochs, as well as characterization of
their
properties (sizes, structure, colors). A quantitative leap in our
understanding
of early galaxies, and the timescales of their buildup,
requires
a total sample of ~100 galaxies at z~7-8 to ~29 AB mag. We can
achieve
this with 192 WFC3 IR orbits on three disjoint fields
(minimizing
cosmic variance): the HUDF and the two nearby deep fields of
the
HUDF05. Our program uses three WFC3 IR filters, and leverages over
600
orbits of existing ACS data, to identify, with low contamination, a
large
sample of over 100 objects at z~7-8, a very useful sample of ~23
at
z~8-9, and limits at z~10. By careful placement of the WFC3 IR and
parallel
ACS pointings, we also enhance the optical ACS imaging on the
HUDF
and a HUDF05 field. We stress (1) the need to go deep, which is
paramount
to define L*, the shape, and the slope alpha of the luminosity
function
(LF) at these high redshifts; and (2) the far superior
performance
of our strategy, compared with the use of strong lensing
clusters,
in detecting significant samples of faint z~7-8 galaxies to
derive
their luminosity function and UV ionizing flux. Our recent z~7.4
NICMOS
results show that wide-area IR surveys, even of GOODS-like depth,
simply
do not reach faint enough at z~7-9 to meet the LF and UV flux
objectives.
In the spirit of the HDF and the HUDF, we will waive any
proprietary
period, and will also deliver the reduced data to STScI. The
proposed
data will provide a Legacy resource of great value for a wide
range
of archival science investigations of galaxies at redshifts z~2-
9.
The data are likely to remain the deepest IR/optical images until
JWST
is launched, and will provide sources for spectroscopic follow up
by
JWST, ALMA and EVLA.
WFC3/ACS/IR
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 WFC3 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.
WFC3/ACS/IR
11840
Identifying
the Host Galaxies for Optically Dark Gamma-Ray Bursts
We
propose to use the high spatial resolution of Chandra to obtain
precise
positions for a sample of Gamma-Ray Bursts (GRBs) with no
optical
afterglows, where the optical light is suppressed relative to
the
X-ray flux. These bursts are likely to be highly obscured and may
have
different environments from the optically bright GRBs. Our Chandra
observations
will (unlike Swift XRT positions) allow for the unique
identification
of a host galaxy. To locate these host galaxies we will
follow
up our Chandra positions with deep optical and IR observations
with
HST. The ultimate aim is to understand any differences between the
host
galaxies of optically dark and bright GRBs, and how these affect
the
use of GRBs as tracers of starformation and galaxy evolution at high
redshift.
WFC3/ACS/UVIS
11684
The
First Proper Motion Measurement for M31: Dynamics and Mass of the
Local
Group
We
will perform observations to determine the proper motion of the
Andromeda
galaxy M31, which has been sought for almost a century without
success.
While challenging, this measurement has now become possible due
to
the availability of existing deep ACS/WFC images of several M31
fields.
The requested second epoch images will yield the average shift
of
the M31 stars with respect to compact galaxies in the background. Our
observing
strategy uses six different fields (three primary and three
coordinated
parallel) with two different instruments (ACS and WFC3) to
provide
a maximum handle on possible systematic effects. The expected
result
will be sufficiently accurate to: (a) discriminate between
different
histories for the dynamics of the Local Group; (b) constrain
the
mass distribution of the Local Group; (c) determine the details of
the
expected future merger between M31 and the Milky Way; (d) infer the
past
interaction history between M31 and M33; (e) constrain the internal
proper
motion kinematics of the M31 spheroid, outer disk, and tidal
stream;
and (f) obtain a pilot estimate of the M31 distance through the
method
of rotational parallax.
WFC3/IR/ACS/WFC
11663
Formation
and Evolution of Massive Galaxies in the Richest Environments
at
1.5 < z < 2.0
We
propose to image seven 1.5<z<2 clusters and groups from the IRAC
Shallow
Cluster Survey with WFC3 and ACS in order to study the formation
and
evolution of massive galaxies in the richest environments in the
Universe
in this important redshift range. We will measure the evolution
of
the sizes and morphologies of massive cluster galaxies, as a function
of
redshift, richness, radius and local density. In combination with
allocated
Keck spectroscopy, we will directly measure the dry merger
fraction
in these clusters, as well as the evolution of Brightest
Cluster
Galaxies (BCGs) over this redshift range where clear model
predictions
can be confronted. Finally we will measure both the epoch of
formation
of the stellar populations and the assembly history of that
stellar
mass, the two key parameters in the modern galaxy formation
paradigm.
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/IR/S/C
12089
Persistence
- Part 2
The
IR detectors on WFC3, like other IR detectors, trap charge when
exposed
to sources near or above the full well of the detector diodes.
This
charge leaks out, producing detectable afterglow images for periods
which
can last for several hours, depending on the amount of over
exposure.
These visits, which consist of tungsten lamp exposures of
varying
durations followed by darks, are intended to provide a better
calibration
of persistence over the full area of the IR detector of
WFC3.
WFC3/UV
12237
Orbits,
Masses, Densities, and Colors of Two Transneptunian Binaries
Binaries
are the key to learning many crucial bulk properties of
transneptunian
objects (TNOs) including their masses. Perhaps the most
interesting
mass-dependent property of a TNO is its bulk density, which
provides
unique information about its bulk composition and interior
structure.
Densities have so far only been measured for a handful of
binary
TNO systems. This proposal seeks to determine orbits and thus
masses
of two more binary TNOs, both of which are also to be observed at
thermal
infrared wavelengths by the Herschel spacecraft. Combining the
masses
from Hubble with the sizes from Herschel will enable us to
compute
their densities. We will also obtain multi-wavelength
photometric
colors of the individual components of each binary system.
It
is imperative to link colors to the physical properties measurable in
binary
systems in order to use the remnant planetesimals in today's
Kuiper
belt to learn more about the early history of our own solar
system,
and more generally about how planetesimals form in nebular disks
and
subsequently evolve.
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
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
11912
UVIS
Internal Flats
This
proposal will be used to assess the stability of the flat field
structure
for the UVIS detector throughout the 15 months of Cycle 17.
The
data will be used to generate on-orbit updates for the delta-flat
field
reference files used in the WFC3 calibration pipeline, if
significant
changes in the flat structure are seen.