HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4617
PERIOD
COVERED: 5am May 22 - 5am May 23, 2008 (DOY 143/0900z-144/0900z)
OBSERVATIONS
SCHEDULED
FGS
11213
Distances
to Eclipsing M Dwarf Binaries
We propose
HST FGS observations to measure accurate distances of 5
nearby
M dwarf eclipsing binary systems, from which model-independent
luminosities
can be calculated. These objects have either poor or no
existing
parallax measurements. FGS parallax determinations for these
systems,
with their existing dynamic masses determined to better than
0.5%,
would serve as model-independent anchor points for the low-mass
end
of the mass-luminosity diagram.
NIC1/NIC2/NIC3
11330
NICMOS
Cycle 16 Extended Dark
This
takes a series of Darks in parallel to other instruments.
NIC1/NIC2/NIC3
8795
NICMOS
Post-SAA calibration - CR Persistence Part 6
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 USEAFTER 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 DARKSs. 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 i
mages.
Each observation will need its own CRMAP, as different SAA
passages
leave different imprints on the NICMOS detectors.
NIC3
11195
Morphologies
of the Most Extreme High-Redshift Mid-IR-luminous Galaxies
II:
The `Bump' Sources
The
formative phase of some of the most massive
galaxies
may be extremely luminous, characterized by intense star- and
AGN-formation.
Till now, few such galaxies have been unambiguously
identified
at high redshift, and thus far we have been restricted to
studying
the low-redshift ultraluminous infrared galaxies as possible
analogs.
We have recently discovered a sample of objects which may
indeed
represent this early phase in galaxy formation, and are
undertaking
an extensive multiwavelength study of this population. These
objects
are optically extremely faint {R>26} but nevertheless bright at
mid-infrared
wavelengths {F[24um] > 0.5 mJy}. Mid-infrared spectroscopy
with
Spitzer/IRS reveals that they have redshifts z~2, implying
luminosities
~1E13 Lsun. Their mid-IR SEDs fall into two broad, perhaps
overlapping,
categories. Sources with brighter F[24um] exhibit power-law
SEDs
and SiO absorption features in their mid-IR spectra characteristic
of
AGN, whereas those with fainter F[24um] show a "bump" characteristic
of
the redshifted 1.6um peak from a stellar population, and PAH emission
characteristic
of starformation. We have begun obtaining HST images of
the
brighter sources in Cycle 15 to obtain identifications and determine
kpc-scale
morphologies for these galaxies. Here, we aim to target the
second
class {the "bump" sources} with the goal of determining if these
constitute
morphologically different objects, or simply a "low-AGN"
state
of the brighter class. The proposed observations will help us
determine
whether these objects are merging systems, massive obscured
starbursts
{with obscuration on kpc scales!} or very reddened {locally
obscured}
AGN hosted by intrinsically low-luminosity galaxies.
NIC3
11334
NICMOS
Cycle 16 Spectrophotometry
Observation
of the three primary WD flux standards must be repeated to
refine
the NICMOS absolute calibration and monitor for sensitivity
degradation.
So far, NICMOS grism spectrophotometry is available for
only
~16 stars with good STIS spectra at shorter wavelengths. There are
more
in the HST CALSPEC standard star data base with good STIS spectra
that
would also become precise IR standards with NICMOS absolute SED
measurements.
Monitoring the crucial three very red stars (M, L, T) for
variability
and better S/N in the IR. Apparent variability was
discovered
at shorter wavelengths during the ACS cross-calibration work
that
revealed a ~2% discrepancy of the cool star fluxes with respect to
the
hot primary WD standards. About a third of these stars are bright
enough
to do in one orbit, the rest require 2 orbits.
S/C
11320
NICMOS
Focus Monitoring Cycle 16
This
program is a version of the standard focus sweep used since cycle
7.
It has been modified to go deeper and uses more narrow filters for
improved
focus determination. A new source was added in Cycle 14 in
order
to accommodate 2-gyro mode: the open cluster NGC1850. This source
is
part of the current proposal. The old target, the open cluster
NGC3603,
will be used whenever available and the new target used to fill
the
periods when NGC3603 is not visible. Steps: a) Use refined target
field
positions as determined from cycle 7 calibrations b) Use
MULTIACCUM
sequences of sufficient dynamic range to account for defocus
c)
Do a 17-point focus sweep, +/- 8mm about the PAM mechanical zeropoint
for
each cameras 1 and 2, in 1.0mm steps. For NIC3 we step from -0.5mm
to
-9.5mm relative to mechanical zero, in steps of 1.0mm. d) Use PAM X/Y
tilt
and OTA offset slew compensations refined from previous focus
monitoring/optical
alignment activities
WEPC2
11196
An
Ultraviolet Survey of Luminous Infrared Galaxies in the Local
Universe
At luminosities
above 10^11.4 L_sun, the space density of far-infrared
selected
galaxies exceeds that of optically selected galaxies. These
Luminous
Infrared Galaxies {LIRGs} are primarily interacting or merging
disk
galaxies undergoing starbursts and creating/fueling central AGN. We
propose
far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W} UV imaging of a
sample
of 27 galaxies drawn from the complete IRAS Revised Bright Galaxy
Sample
{RBGS} LIRGs sample and known, from our Cycle 14 B and I-band ACS
imaging
observations, to have significant numbers of bright {23 < B < 21
mag}
star clusters in the central 30 arcsec. The HST UV data will be
combined
with previously obtained HST, Spitzer, and GALEX images to {i}
calculate
the ages of the clusters as function of merger stage, {ii}
measure
the amount of UV light in massive star clusters relative to
diffuse
regions of star formation, {iii} assess the feasibility of using
the
UV slope to predict the far-IR luminosity {and thus the star
formation
rate} both among and within IR-luminous galaxies, and {iv}
provide
a much needed catalog of rest- frame UV morphologies for
comparison
with rest-frame UV images of high-z LIRGs and Lyman Break
Galaxies.
These observations will achieve the resolution required to
perform
both detailed photometry of compact structures and spatial
correlations
between UV and redder wavelengths for a physical
interpretation
our IRX-Beta results. The HST UV data, combined with the
HST
ACS, Spitzer, Chandra, and GALEX observations of this sample, will
result
in the most comprehensive study of luminous starburst galaxies to
date.
WFPC2
11122
Expanding
PNe: Distances and Hydro Models
We
propose to obtain repeat narrowband images of a sample of eighteen
planetary
nebulae {PNe} which have HST/WFPC2 archival data spanning time
baselines
of a decade. All of these targets have previous high
signal-to-noise
WFPC2/PC observations and are sufficiently nearby to
have
readily detectable expansion signatures after a few years. Our main
scientific
objectives are {a} to determine precise distances to these
PNe
based on their angular expansions, {b} to test detailed and highly
successful
hydrodynamic models that predict nebular morphologies and
expansions
for subsamples of round/elliptical and axisymmetric PNe, and
{c}
to monitor the proper motions of nebular microstructures in an
effort
to learn more about their physical nature and formation
mechanisms.
The proposed observations will result in high-precision
distances
to a healthy subsample of PNe, and from this their expansion
ages,
luminosities, CSPN properties, and masses of their ionized cores.
With
good distances and our hydro models, we will be able to determine
fundamental
parameters {such as nebular and central star masses,
luminosity,
age}. The same images allow us to monitor the changing
overall
ionization state and to search for the surprisingly
non-homologous
growth patterns to bright elliptical PNe of the same sort
seen
by Balick & Hajian {2004} in NGC 6543. Non-uniform growth is a sure
sign
of active pressure imbalances within the nebula that require
careful
hydro models to understand.
WFPC2
11176
Location
and the Origin 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. A number of hosts of SGRBs have been identified, and
have
been used by some to argue that SGRBs derive primarily from an
ancient
population {~ 5 Gyr}; however, it is not known whether this
conclusion
more accurately reflects selection biases or astrophysics.
Here
we propose to employ a variant of a technique that we pioneered and
used
to great effect in elucidating the origins of long-duration bursts.
We
will examine the degree to which SGRB locations trace the red or blue
light
of their hosts, and thus old or young stellar populations. This
approach
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, and should give direct insight
into
the age of the SGRB progenitor population.
WFPC2
11202
The
Structure of Early-type Galaxies: 0.1-100 Effective Radii
The
structure, formation and evolution of early-type galaxies is still
largely
an open problem in cosmology: how does the Universe evolve from
large
linear scales dominated by dark matter to the highly non-linear
scales
of galaxies, where baryons and dark matter both play important,
interacting,
roles? To understand the complex physical processes
involved
in their formation scenario, and why they have the tight
scaling
relations that we observe today {e.g. the Fundamental Plane}, it
is critically
important not only to understand their stellar structure,
but
also their dark-matter distribution from the smallest to the largest
scales.
Over the last three years the SLACS collaboration has developed
a
toolbox to tackle these issues in a unique and encompassing way by
combining
new non-parametric strong lensing techniques, stellar
dynamics,
and most recently weak gravitational lensing, with
high-quality
Hubble Space Telescope imaging and VLT/Keck spectroscopic
data
of early-type lens systems. This allows us to break degeneracies
that
are inherent to each of these techniques separately and probe the
mass
structure of early-type galaxies from 0.1 to 100 effective radii.
The
large dynamic range to which lensing is sensitive allows us both to
probe
the clumpy substructure of these galaxies, as well as their
low-density
outer haloes. These methods have convincingly been
demonstrated,
by our team, using smaller pilot-samples of SLACS lens
systems
with HST data. In this proposal, we request observing time with
WFPC2
and NICMOS to observe 53 strong lens systems from SLACS, to obtain
complete
multi-color imaging for each system. This would bring the total
number
of SLACS lens systems to 87 with completed HST imaging and
effectively
doubles the known number of galaxy-scale strong lenses. The
deep
HST images enable us to fully exploit our new techniques, beat down
low-number
statistics, and probe the structure and evolution of
early-type
galaxies, not only with a uniform data-set an order of
magnitude
larger than what is available now, but also with a fully
coherent
and self-consistent methodological approach!
WFPC2
11227
The
orbital period for an ultraluminous X-ray source in NGC1313
The
ultraluminous X-ray sources {ULXs} are extragalactic point sources
with
luminosities that exceed the Eddington luminosity for conventional
stellar-mass
black holes by factors of 10 - 100. It has been hotly
debated
whether the ULXs are just common stellar-mass black hole sources
with
beamed emission or whether they are sub-Eddington sources that are
powered
by the long-sought intermediate mass black holes {IMBH}. To
firmly
decide this question, one must obtain dynamical mass measurements
through
photometric and spectroscopic monitoring of the secondaries of
these
system. The crucial first step is to establish the orbital period
of
a ULX, and arguably the best way to achieve this goal is by
monitoring
its ellipsoidal light curve. The extreme ULX NGC1313 X-2
provides
an outstanding target for an orbital period determination
because
its relatively bright optical counterpart {V = 23.5} showed a
15%
variation between two HST observations separated by three months.
This
level of variability is consistent with that expected for a tidally
distorted
secondary star. Here we propose a set of 20 imaging
observations
with HST/WFPC2 to define the orbital period. This would be
the
first photometric measurement of the orbital period of a ULX binary.
Subsequently,
we will propose to obtain spectroscopic observations to
obtain
its radial velocity amplitude and thereby a dynamical estimate of
its
mass.
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
08
08
FGS
REacq
07
07
OBAD
with Maneuver
30
30
SIGNIFICANT
EVENTS: (None)