Notice: For the foreseeable future, the daily reports may
contain
apparent discrepancies between some proposal descriptions
and the listed
instrument usage. This is due to the conversion of
previously approved
ACS WFC or HRC observations into WFPC2, or NICMOS
observations
subsequent to the loss of ACS CCD science capability in late
January.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4395
PERIOD COVERED: UT June 29,30, July 01, 2007 (DOY
180,181,182)
OBSERVATIONS SCHEDULED
NIC1/NIC2/NIC3 8794
NICMOS Post-SAA calibration - CR Persistence Part 5
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
images. Each observation will need its own CRMAP, as
different SAA
passages leave different imprints on the NICMOS detectors.
WFPC2 11289
SL2S: The Strong Lensing Legacy Survey
Recent systematic surveys of strong galaxy-galaxy lenses
{CLASS, SLACS,
GOODS, etc.} are producing spectacular results for galaxy
masses roughly
below a transition mass M~10^13 Mo. The observed lens
properties and
their evolution up to z~0.2, consistent with numerical
simulations, can
be described by isothermal elliptical potentials. In
contrast, modeling
of giant arcs in X-ray luminous clusters {halo masses M
>~10^13 Mo}
favors NFW mass profiles, suggesting that dark matter halos
are not
significantly affected by baryon cooling. Until recently,
lensing
surveys were neither deep nor extended enough to probe the
intermediate
mass density regime, which is fundamental for understanding
the assembly
of structures. The CFHT Legacy Survey now covers 125 square
degrees, and
thus offers a large reservoir of strong lenses probing a
large range of
mass densities up to z~1. We have extracted a list of 150
strong lenses
using the most recent CFHTLS data release via automated
procedures.
Following our first SNAPSHOT proposal in cycle 15, we
propose to
continue the Hubble follow-up targeting a larger list of 130
lensing
candidates. These are intermediate mass range candidates
{between
galaxies and clusters} that are selected in the redshift
range of 0.2-1
with no a priori X-ray selection. The HST resolution is
necessary for
confirming the lensing candidates, accurate modeling of the
lenses, and
probing the total mass concentration in galaxy groups up to
z~1 with the
largest unbiased sample available to date.
WFPC2 11235
HST NICMOS Survey of the Nuclear Regions 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 enhanced star formation and
Active
Galactic Nuclei {AGN} activity, possibly triggered as the
objects
transform into massive S0 and elliptical merger remnants. We
propose
NICMOS NIC2 imaging of the nuclear regions of a complete
sample of 88
L_IR > 10^11.4 L_sun luminous infrared galaxies in the
IRAS Revised
Bright Galaxy Sample {RBGS: i.e., 60 micron flux density
> 5.24 Jy}.
This sample is ideal not only in its completeness and sample
size, but
also in the proximity and brightness of the galaxies. The
superb
sensitivity and resolution of NICMOS NIC2 on HST enables a
unique
opportunity to study the detailed structure of the nuclear
regions,
where dust obscuration may mask star clusters, AGN and
additional nuclei
from optical view, with a resolution significantly higher
than possible
with Spitzer IRAC. This survey thus provides a crucial
component to our
study of the dynamics and evolution of IR galaxies presently
underway
with Wide-Field, HST ACS/WFC and Spitzer IRAC observations
of these 88
galaxies. Imaging will be done with the F160W filter
{H-band} to examine
as a function of both luminosity and merger stage {i} the
luminosity and
distribution of embedded star clusters, {ii} the presence of
optically
obscured AGN and nuclei, {iii} the correlation between the
distribution
of 1.6 micron emission and the mid-IR emission as detected
by Spitzer
IRAC, {iv} the evidence of bars or bridges that may funnel
fuel into the
nuclear region, and {v} the ages of star clusters for which
photometry
is available via ACS/WFC observations. The NICMOS data,
combined with
the HST ACS, Spitzer, and GALEX observations of this sample,
will result
in the most comprehensive study of merging and interacting
galaxies to
date.
FGS 11211
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
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.
WFPC2 11079
Treasury Imaging of Star Forming Regions in the Local Group:
Complementing the GALEX and NOAO Surveys
We propose to use WFPC2 to image the most interesting
star-forming
regions in the Local Group galaxies, to resolve their young
stellar
populations. We will use a set of filters including F170W,
which is
critical to detect and characterize the most massive stars,
to whose hot
temperatures colors at longer wavelengths are not sensitive.
WFPC2's
field of view ideally matches the typical size of the
star-forming
regions, and its spatial resolution allows us to measure
indvidual
stars, given the proximity of these galaxies. The resulting
H- R
diagrams will enable studies of star-formation properties in
these
regions, which cover largely differing metallicities {a
factor of 17,
compared to the factor of 4 explored so far} and
characteristics. The
results will further our understanding of the star-formation
process, of
the interplay between massive stars and environment, the
properties of
dust, and will provide the key to interpret integrated measurements
of
star-formation indicators {UV, IR, Halpha} available for
several
hundreds more distant galaxies. Our recent deep surveys of
these
galaxies with GALEX {FUV, NUV} and ground-based imaging
{UBVRI, Halpha,
[OIII] and [SII]} provided the identification of the most
relevant SF
sites. In addition to our scientific analysis, we will
provide catalogs
of HST photometry in 6 bands, matched corollary ground-based
data, and
UV, Halpha and IR integrated measurements of the
associations, for
comparison of integrated star-formation indices to the
resolved
populations. We envisage an EPO component.
WFPC2 11029
WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation
Anomaly
Monitor
Intflat observations will be taken to provide a linearity
check: the
linearity test consists of a series of intflats in F555W, in
each gain
and each shutter. A combination of intflats, visflats, and
earthflats
will be used to check the repeatability of filter wheel
motions.
{Intflat sequences tied to decons, visits 1-18 in prop
10363, have been
moved to the cycle 15 decon proposal xxxx for easier
scheduling.} Note:
long-exposure WFPC2 intflats must be scheduled during ACS
anneals to
prevent stray light from the WFPC2 lamps from contaminating
long ACS
external exposures.
WFPC2 11027
Visible Earth Flats
This proposal monitors flatfield stability. This proposal
obtains
sequences of Earth streak flats to construct high quality
flat fields
for the WFPC2 filter set. These flat fields will allow
mapping of the
OTA illumination pattern and will be used in conjuction with
previous
internal and external flats to generate new pipeline
superflats. These
Earth flats will complement the Earth flat data obtained
during cycles
4-14.
NIC3 10926
GRB afterglows and host galaxies at very high redshifts
Cosmology is beginning to constrain the nature of the
earliest stars and
galaxies to form in the universe, but direct observation of
galaxies at
z>6 remains highly challenging due to their scarcity,
intrinsically
small size, and high luminosity distance. GRB afterglows,
thanks to
their extreme luminosities, offer the possibility of
circumventing these
normal constraints by providing redshifts and spectral
information which
couldn't be obtained by direct observation of the host
galaxies
themselves. In addition, the association of GRBs with
massive stars
means that they are a tracer of star formation, and that
their hosts are
likely responsible for a large proportion of the ionizing
radiation
during that era. Our collaboration is conducting a campaign
to rapidly
identify and study candidate very high redshift bursts,
bringing to bear
a network of 2, 4 and 8m telescopes with near-IR
instrumentation. Swift
has proven capable of detecting faint, distant GRBs, and
reporting
accurate positions for many bursts in near real-time. Here
we propose to
continue our HST program of targeting z>6 GRBs. HST is
crucial to this
endeavour, allowing us {a} to characterise the basic
properties, such as
luminosity and colour, and in some cases morphologies, of
the hosts,
which is essential to understanding these primordial
galaxies and their
relationship to other galaxy populations; and {b} to monitor
the late
time afterglows and hence compare them to lower-z bursts and
test the
use of GRBs as standard candles
WFPC2 10916
A Study of SN Ejecta in the Core-Collapse Supernova Remnant
G292.0+1.8:
Cas A's Older Cousin
Recent studies of the southern oxygen-rich supernova remnant
{SNR}
G292.0+1.8 have shown it to be the only Galactic SNR to
exhibit all the
features we expect in young remnants of core-collapse
supernovae: an
outer shell behind an expanding primary shock, high-velocity
fragments
of undiluted metal-rich ejecta, and a central pulsar
surrounded by a
pulsar-wind nebula. G292.0+1.8's optical emission consists
of numerous
knots and filaments of O- and S-rich ejecta spread
throughout much of
the remnant shell, many with radially oriented pencil-like
geometries
that may trace their origins to Rayleigh-Taylor instabilities
during the
SN event. The evolution and fine-scale structure of SN
debris in young
remnants is poorly understood and largely uncharted
territory. For
testing models for the distribution of metal-rich ejecta
from
core-collapse SNe, how the ejecta evolve and clump, and how
SN shocks
interact with the local circumstellar medium, the
3000-yr-old G292.0+1.8
remnant rivals the 320-yr-old Cas A remnant in importance.
We therefore
propose the first HST images of G292.0+1.8 in order to
characterize the
fine-scale spatial distribution of the ejecta, their
sub-arcsecond
chemical make-up, and the detailed structure and scale
lengths for
metal-rich SN ejecta clumps. The proposed HST images of
G292.0+1.8 will
be used in conjunction with existing Spitzer Cycle 1 infrared
data and
an upcoming 0.5 Msec Chandra X-ray image. We expect to
achieve the same
kind of results for G292 that have already been obtained for
Cas A.
High-resolution HST images of this remnant, combined with
Spitzer and
Chandra data and contrasted with a similar data set on Cas
A, will
provide superb multiwavelength benchmarks for both very
young and older
core-collapse SNRs.
WFPC2 10903
Resolving the LMC Microlensing Puzzle: Where are the Lensing
Objects?
We are requesting 12 HST orbits to continue to investigate
the nature of
the population that gives rise to the microlensing seen
towards the LMC.
This proposal builds on the cycle 14 HST program {10583} and
will
complement the study with 12 yet-to-be discovered
microlensing
candidates from Fall 2006. Our SuperMacho project is an
ongoing ground-
based survey on the CTIO 4m that has demonstrated the
ability to detect
LMC microlensing events via frame subtraction. The
combination of high
angular resolution and photometric accuracy with HST will
allow us to 1}
confrim that the detected flux excursions arise from LMC
stars, rather
than background supernovae or AGN, and 2} obtain reliable
baseline flux
measurements for the objects in their unlensed state. This
latter
measurement in important in determining the microlensing
optical depth
towards the LMC.
WFPC2 10884
The Dynamical Structure of Ellipticals in the Coma and Abell
262
Clusters
We propose to obtain images of 13 relatively luminous early
type
galaxies in the Coma cluster and Abell 262 for which we have
already
collected ground based major and minor axis spectra and
images. The
higher resolution HST images will enable us to study the
central regions
of these galaxies which is crucial to our dynamical
modelling. The
complete data set will allow us to perform a full dynamical
analysis and
to derive the dark matter content and distribution, the
stellar orbital
structure, and the stellar population properties of these
objects,
probing the predictions of galaxy formation models. The
dynamical
analysis will be performed using an up-to-date axi-symmetric
orbit
superposition code.
WFPC2 10834
The Shell of the Recurrent Nova T Pyx
T Pyx is the only known recurrent nova with a shell. This
'shell' is
mysterious because it has been resolved into thousands of
knots that
apparently aren't expanding. We propose to take a deep F658N
image of T
Pyx during one orbit to serve as a 12 year baseline from the
previous
HST WFPC2 images in 1994 and 1995. This much longer baseline
will allow
us to push down the limits on expansion velocities to ~10
km/s and will
allow us to measure the lifetimes of the knots. Also, we
expect to
discover the expanding inner shell from the last eruption in
1966 which
should now have expanded to ~0.9" in radius. Detailed
modeling of the
observed line fluxes will give the mass of the individual
knots and the
shells. The details of the expansion velocities, lifetimes,
and masses
of the knots will determine the nature of the T Pyx shell;
with
alternatives being a nova shell, a planetary nebula, stalled
shocks in a
pre-existing shell, or a cloud ionized by the high
luminosity and
temperature of the white dwarf. If we can separate out the
mass ejected
during the 1966 eruption, then we can compare it to the
total mass
accreted between the 1944 and 1966 eruptions {6.0x10^-6
solar mass} so
as to determine whether the white dwarf is gaining or losing
mass on
average. If the white dwarf is gaining mass, then it must
inevitably
exceed the Chandrasekhar mass and collapse as a Type Ia
supernova, and
thus recurrent novae would be shown to be an important
component of the
solution to the Type Ia progenitor problem.
WFPC2 10818
Very Young Globular Clusters in M31 ?
We propose to use HST's unique high spatial resolution
imaging
capabilities to conclusively confirm or refute the presence
of alleged
very young globular clusters in M31. Such young globular
clusters with
ages < 3 Gyr are not present in our galaxy, and, if real,
would lead to
a striking difference in the age distribution of the GCs
between M31 and
the
in M31 is confirmed through our proposed ACS imaging {now
WFPC2 imaging}
with HST, this would suggest major differences in the
history of
assembly of the two galaxies, with probable substantial late
accretion
into M31 which did not occur in our own galaxy.
WFPC2 10800
Kuiper Belt Binaries: Probes of Early Solar System Evolution
Binaries in the Kuiper Belt are a scientific windfall: in
them we have
relatively fragile test particles which can be used as
tracers of the
early dynamical evolution of the outer Solar System. We
propose to
continue a Snapshot program using the ACS/HRC that has a
demonstrated
discovery potential an order of magnitude higher than the
HST
observations that have already discovered the majority of
known
transneptunian binaries. With this continuation we seek to
reach the
original goals of this project: to accumulate a sufficiently
large
sample in each of the distinct populations collected in the
Kuiper Belt
to be able to measure, with statistical significance, how
the fraction
of binaries varies as a function of their particular
dynamical paths
into the Kuiper Belt. Today's Kuiper Belt bears the imprints
of the
final stages of giant-planet building and migration;
binaries may offer
some of the best preserved evidence of that long-ago era.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
10875 - GSAcq(1,2,2) failed to RGA
Hold (Gyro Control) GSAcq(1,2,2), scheduled for 181/16:21:41
failed to
RGA Hold (Gyro Control) at 181/16:25:26. One 486 ESB message
"a0a" (FGS
Fine Lock failed-Timed out waiting for fine lock) was
received.
Acquisition walkdown entered Coarse Track (CT) multiple
times before
returning to default. The Primary guide star magnitude was
11.297.
10876 - GSAcq(1,2,1) failed to RGA Hold (Gyro Control) The
GSAcq(1,2,1)
scheduled at 181/18:06:44 - 18:14:19 failed to RGA Hold due
to
(QF1STOPF) stop flag indication on FGS-1. Pre-acquisition
OBADs were
successful. OBAD2 had (RSS) value of 14.61 arcseconds.
Post-acq OBAD/MAP
had (RSS) value of 7.25 arcseconds.
COMPLETED OPS REQUEST: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
22
20
FGS
REacq
13
13
OBAD with Maneuver
70
70
COMPLETED OPS NOTES: (None)
SIGNIFICANT EVENTS: (None)