HUBBLE
SPACE TELESCOPE - Continuing to Collect World Class Science
DAILY
REPORT #5077
PERIOD
COVERED: 5am April 16 - 5am April 19, 2010 (DOY 106/09:00z-109/09:00z)
OBSERVATIONS
SCHEDULED
WFC3/UVIS
12018
Ultra-Luminous
X-Ray Sources in the Most Metal-Poor Galaxies
There
is growing observational and theoretical evidence to suggest that
Ultra-Luminous
X-ray sources (ULX) form preferentially in low
metallicity
environments. Here we propose a survey of 27 nearby (<
30Mpc)
star-forming Extremely Metal Poor Galaxies (Z<5% solar). There
are
almost no X-ray observations of such low abundance galaxies (3 in
the
Chandra archive). These are the most metal-deficient galaxies known,
and
a logical place to find ULX if they favor metal-poor systems. We
plan
to test recent population synthesis models which predict that ULX
should
be very numerous in metal-poor galaxies. We will also test the
hypothesis
that ULX form in massive young star clusters, and ask for HST
time
to obtain the necessary imaging data.
ACS/WFC
12017
The
Proper Motion of SNR E0519-69.0
We
propose to measure independently the proper motion expansions of the
ejecta
and forward shock in SNR E0519-69.0. The metal-enriched
reverse-shock-heated
ejecta emits only in X-rays, while the forward
shock
is traced to high precision by H alpha emission. The proposed
measurements
require the unique high resolution imaging capabilities of
Chandra
and Hubble. The optical (forward shock) and X-ray (ejecta)
results
will yield important constraints on the remnant's evolutionary
state;
we will search in particular for evidence of cosmic-ray modified
dynamics.
An important component of this project is an integrated
theoretical
investigation using realistic models of SN Ia explosions
evolved
to the remnant stage.
COS/FUV
11997
FUV
Internal/External Wavelength Scale Monitor
This
program monitors the offsets between the wavelength scale set by
the
internal wavecal versus that defined by absorption lines in external
targets.
This is accomplished by observing two external targets in the
SMC:
SK191 with G130M and G160M and Cl* NGC 330 ROB B37 with G140L
(SK191
is too bright to be observed with G140L). The cenwaves observed
in
this program are a subset of the ones used during Cycle 17. Observing
all
cenwaves would require a considerably larger number of orbits.
Constraints
on scheduling of each target are placed so that each target
is
observed once every ~2-3 months. Observing the two targets every
month
would also require a considerably larger number of orbits.
ACS/WFC
11995
CCD
Daily Monitor (Part 2)
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 320 orbits (20 weeks) from 1 February 2010 to 20 June
2010.
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
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
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
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.
FGS
11874
Monitoring
FGS2R2 S-Curves after SMOV4
This
proposal satisfies the near-term requirement associated with SMOV4
activity
OTA/FGS-10, as well as the long term Cycle 17 requirement to
monitor
the post SM4 evolution of the FGS2R2 S-curves stability during
its
first year on orbit. The S curves will be obtained from Trans mode
observations
of stars (point sources) at several locations in the FGS2R2
FOV
in order to monitor both global and differential (i.e.,
field-dependent)
changes. At each location, both F583W and PUPIL
S-curves
will be obtained. Stars in the M35 cluster will be used for
this
proposal since the field lies very near the ecliptic and can
therefore
be observed by HST at two Orients from August to May.
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/CC
11845
CCD
Dark Monitor Part 2
Monitor
the darks for the STIS CCD.
ACS/WFC/WFC3/IR
11802
WFC3/IR
Observations of Strongly Lensing Clusters
We
propose WFC3/IR observations of the massive lensing clusters Abell
1689
and Abell 1703 to constrain the properties of both cluster and
background
field galaxies. The dataset will also help constrain the
photometric
redshift of A1689-zD1, the bright galaxy candidate at z~7.6.
ACS/WFC3
11735
The
LSD Project: Dynamics, Merging and Stellar Populations of a Sample
of
Well-Studied LBGs at z~3
A
large observational effort with the ground-based ESO/VLT telescopes
allowed
us to obtain deep, spatially-resolved, near-IR spectra of
complete
sample of 11 Lyman-Break Galaxies at z~3.1. These observations
were
used to obtain, for the first time, the metallicity and the
dynamical
properties of a sample of objects that, albeit small, is
representative
of the total population of the LBGs. We propose to use
HST
to obtain high-resolution optical and near-IR images of this sample
of
LBGs in order to study the broad-band morphology and the stellar
light
distribution of these galaxies. These images, exploiting the
superior
spatial resolution of HST images and the low-background : 1-
will
allow a precise measure of the dynamical mass from the velocity
field
derived with spectroscopy; 2- will permit a comparison of the
distribution
of star formation (from the line emission) with the
underlying
stellar population, and, 3- will be used to check if the
complex
velocity field and the multiple line-emitting regions detected
in
most targets can be ascribed to on-going mergers. This accurate study
will
shed light on a number of unsolved problems still affecting the
knowledge
of the LBGs.
ACS/WFC
11715
The
Luminous Galactic Cepheid RS Puppis: A Geometric Distance from its
Nested
Light Echoes
RS
Puppis is one of the most luminous Cepheids in the Milky Way (P =
41.4
days) and an analog of the bright Cepheids used to measure
extragalactic
distances. An accurate distance would help anchor the
zero-point
of the bright end of the period-luminosity relation, but at a
distance
of about 2 kpc it is too far away for a trigonometric parallax
with
existing instrumentation.
RS
Pup is unique in being surrounded by a reflection nebula, whose
brightness
varies as pulses of light from the Cepheid propagate
outwards.
Members of our team have used ground-based imaging of the
nebula
to derive phase lags in the light variations of individual
features
in the nebula, and have inferred a seemingly very precise
geometric
distance to the star. However, there is an unavoidable
ambiguity
involving the cycle counts, which was resolved by assuming
that
the features lie in the plane of the sky. If this assumption is
incorrect,
a large systematic error would be introduced into the
distance
measurement.
We
show that polarimetric imaging using the high spatial resolution of
ACS/WFC
and its ability to image close to the star can resolve this
ambiguity
and yield a reliable geometric distance to RS Pup. We will
also
obtain a wide-field multicolor image of the nebula, in order to
study
its morphology and the mass-loss history of the Cepheid.
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/ACS/IR
11600
Star
Formation, Extinction, and Metallicity at 0.7<z<1.5: H-Alpha Fluxes
and
Sizes from a Grism Survey of GOODS-N
The
global star formation rate (SFR) is ~10x higher at z=1 than today.
This
could be due to drastically elevated SFR in some fraction of
galaxies,
such as mergers with central bursts, or a higher SFR across
the
board. Either means that the conditions in z=1 star forming galaxies
could
be quite different from local objects. The next step beyond
measuring
the global SFR is to determine the dependence of SFR,
obscuration,
metallicity, and size of the star-forming region on galaxy
mass
and redshift. However, SFR indicators at z=1 typically apply local
calibrations
for UV, [O II] and far-IR, and do not agree with each other
on
a galaxy-by-galaxy basis. Extinction, metallicity, and dust
properties
cause uncontrolled offsets in SFR calibrations. The great
missing
link is Balmer H-alpha, the most sensitive probe of SFR. We
propose
a slitless WFC3/G141 IR grism survey of GOODS-N, at 2
orbits/pointing.
It will detect Ha+[N II] emission from 0.7<z<1.5, to
L(Ha)
= 1.7 x 10^41 erg/sec at z=1, measuring H-alpha fluxes and sizes
for
> 600 galaxies, and a small number of higher-redshift emitters. This
will
produce: an emission-line redshift survey unbiased by magnitude and
color
selection; star formation rates as a function of galaxy
properties,
e.g. stellar mass and morphology/mergers measured by ACS;
comparisons
of SFRs from H-alpha to UV and far-IR indicators;
calibrations
of line ratios of H-alpha to important nebular lines such
as
[O II] and H-beta, measuring variations in metallicity and extinction
and
their effect on SFR estimates; and the first measurement of scale
lengths
of the H-alpha emitting, star- forming region in a large sample
of
z~1 sources.
COS/NUV/FUV
11598
How
Galaxies Acquire their Gas: A Map of Multiphase Accretion and
Feedback
in Gaseous Galaxy Halos
We
propose to address two of the biggest open questions in galaxy
formation
- how galaxies acquire their gas and how they return it to the
IGM
- with a concentrated COS survey of diffuse multiphase gas in the
halos
of SDSS galaxies at z = 0.15 - 0.35. Our chief science goal is to
establish
a basic set of observational facts about the physical state,
metallicity,
and kinematics of halo gas, including the sky covering
fraction
of hot and cold material, the metallicity of infall and
outflow,
and correlations with galaxy stellar mass, type, and color -
all
as a function of impact parameter from 10 - 150 kpc. Theory suggests
that
the bimodality of galaxy colors, the shape of the luminosity
function,
and the mass-metallicity relation are all influenced at a
fundamental
level by accretion and feedback, yet these gas processes are
poorly
understood and cannot be predicted robustly from first
principles.
We lack even a basic observational assessment of the
multiphase
gaseous content of galaxy halos on 100 kpc scales, and we do
not
know how these processes vary with galaxy properties. This ignorance
is
presently one of the key impediments to understanding galaxy
formation
in general. We propose to use the high-resolution gratings
G130M
and G160M on the Cosmic Origins Spectrograph to obtain sensitive
column
density measurements of a comprehensive suite of multiphase ions
in
the spectra of 43 z < 1 QSOs lying behind 43 galaxies selected from
the
Sloan Digital Sky Survey. In aggregate, these sightlines will
constitute
a statistically sound map of the physical state and
metallicity
of gaseous halos, and subsets of the data with cuts on
galaxy
mass, color, and SFR will seek out predicted variations of gas
properties
with galaxy properties. Our interpretation of these data will
be
aided by state-of-the-art hydrodynamic simulations of accretion and
feedback,
in turn providing information to refine and test such models.
We
will also use Keck, MMT, and Magellan (as needed) to obtain optical
spectra
of the QSOs to measure cold gas with Mg II, and optical spectra
of
the galaxies to measure SFRs and to look for outflows. In addition to
our
other science goals, these observations will help place the Milky
Way's
population of multiphase, accreting High Velocity Clouds (HVCs)
into
a global context by identifying analogous structures around other
galaxies.
Our program is designed to make optimal use of the unique
capabilities
of COS to address our science goals and also generate a
rich
dataset of other absorption-line systems
WFC3/UVIS
11595
Turning
Out the Light: A WFC3 Program to Image z>2 Damped Lyman Alpha
Systems
We
propose to directly image the star-forming regions of z>2 damped Lya
systems
(DLAs) using the WFC3/UVIS camera on the Hubble Space Telescope.
In
contrast to all previous attempts to detect the galaxies giving rise
to
high redshift DLAs, we will use a novel technique that completely
removes
the glare of the background quasar. Specifically, we will target
quasar
sightlines with multiple DLAs and use the higher redshift DLA as
a
``blocking filter'' (via Lyman limit absorption) to eliminate all FUV
emission
from the quasar. This will allow us to carry out a deep search
for
FUV emission from the lower redshift DLA, shortward of the Lyman
limit
of the higher redshift absorber. The unique filter set and high
spatial
resolution afforded by WFC3/UVIS will then enable us to directly
image
the lower redshift DLA and thus estimate its size, star- formation
rate
and impact parameter from the QSO sightline. We propose to observe
a
sample of 20 sightlines, selected primarily from the SDSS database,
requiring
a total of 40 HST orbits. The observations will allow us to
determine
the first FUV luminosity function of high redshift DLA
galaxies
and to correlate the DLA galaxy properties with the ISM
characteristics
inferred from standard absorption-line analysis to
significantly
improve our understanding of the general DLA population.
ACS/SBC/COS/NUV/FUV
11579
The
Difference Between Neutral- and Ionized-Gas Metal Abundances in
Local
Star-Forming Galaxies with COS
The
metallicity of galaxies and its evolution with redshift is of
paramount
importance for understanding galaxy formation. Abundances in
the
interstellar medium (ISM) are typically determined using
emission-line
spectroscopy of HII regions. However, since HII regions
are
associated with recent SF they may not have abundances typical for
the
galaxy as a whole. This is true in particular for star-forming
galaxies
(SFGs), in which the bulk of the metals may be contained in the
neutral
gas. It is therefore important to directly probe the metal
abundances
in the neutral gas. This can be done using absorption lines
in
the Far UV. We have developed techniques to do this in SFGs, where
the
absorption is measured for sightlines toward bright SF regions
within
the galaxy itself. We have successfully applied this technique to
a
sample of galaxies observed with FUSE. The results have been very
promising,
suggesting in I Zw 18 that abundances in the neutral gas may
be
up to 0.5 dex lower than in the ionized gas. However, the
interpretation
of the FUSE data is complicated by the very large FUSE
aperture
(30 arcsec), the modest S/N, and the limited selection of
species
available in the FUSE bandpass. The advent of COS on HST now
allows
a significant advance in all of these areas. We will therefore
obtain
absorption line spectroscopy with G130M in the same sample for
which
we already have crude constraints from FUSE. We will obtain
ACS/SBC
images to select the few optimal sightlines to target in each
galaxy.
The results will be interpreted through line-profile fitting to
determine
the metal abundances constrained by the available lines. The
results
will provide important new insights into the metallicities of
galaxies,
and into outstanding problems at high redshift such as the
observed
offset between the metallicities of Lyman Break Galaxies and
Damped
Lyman Alpha systems.
NIC2/WFC3/IR
11219
Active
Galactic Nuclei in Nearby Galaxies: A New View of the Origin of
the
Radio-Loud Radio- Quiet Dichotomy?
Using
archival HST and Chandra observations of 34 nearby early-type
galaxies
(drawn from a complete radio selected sample) we have found
evidence
that the radio-loud/radio-quiet dichotomy is directly connected
to
the structure of the inner regions of their host galaxies in the
following
sense: [1] Radio-loud AGN are associated with galaxies with
shallow
cores in their light profiles [2] Radio-quiet AGN are only
hosted
by galaxies with steep cusps. Since the brightness profile is
determined
by the galaxy's evolution, through its merger history, our
results
suggest that the same process sets the AGN flavor. This provides
us
with a novel tool to explore the co-evolution of galaxies and
supermassive
black holes, and it opens a new path to understand the
origin
of the radio-loud/radio-quiet AGN dichotomy. Currently our
analysis
is statistically incomplete as the brightness profile is not
available
for 82 of the 116 targets. Most galaxies were not observed
with
HST, while in some cases the study is obstructed by the presence of
dust
features. We here propose to perform an infrared NICMOS snapshot
survey
of these 82 galaxies. This will enable us to i) test the reality
of
the dichotomic behavior in a substantially larger sample; ii) extend
the
comparison between radio-loud and radio-quiet AGN to a larger range
of
luminosities.
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
21
21
FGS
REAcq
22
22
OBAD
with Maneuver 16
16
SIGNIFICANT
EVENTS:
Flash
Reports:
The
new acquisition PLCP groups were used at the start of the 109 SMS.
All
indications are that the first two acquisitions were successful.