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 # 4356
PERIOD COVERED: UT May 04,05,06, 2007 (DOY 124,125,126)
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.
NIC3 11080
Exploring the Scaling Laws of Star Formation
As a variety of surveys of the local and distant Universe
are
approaching a full census of galaxy populations, our
attention needs to
turn towards understanding and quantifying the physical
mechanisms that
trigger and regulate the large-scale star formation rates
{SFRs} in
galaxies.
ACS/SBC 11056
Improved Sensitivity SBC Prisms
The flux calibration of the SBC {PR110L and PR130L} will
be improved by
observing for each prism white dwarf standards {WD1657+343
and LTT9491}.
The blue standard star WD1657+343 has previously been
observed with
ACS/SBC and will serve as a reference point to track time
dependent
variations. LTT9491 is much redder and thus will be used
to investigate
the sensitivity curve of ?red? targets to check for a
potential red leak
of the SBC. Additionally, LTT9491 shows various strong
absorption lines
which can be used to confirm the wavelength calibration of
the PR110L
and PR130L prisms. The standard stars are observed at a
variety of
pointings across the SBC detector in order to map spatial
variations.
LTT9491 will also be observed with ACS/HRC PR200L to
obtain an improved
flux calibration from about 1800 A to 4000 A.
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.
ACS/SBC/WFPC2 10904
Star formation in extended UV disk {XUV-disk} galaxies
The Galaxy Evolution Explorer {GALEX} has discovered the
existence of
extended UV-disk {XUV-disk} galaxies. This class of
intriguing spiral
galaxies is distinguished by UV-bright regions of star
formation located
at extreme galactocentric radii, commonly reaching many
times the
optical extent of each target. XUV-disks represent a
population of
late-type galaxies still actively building, or
significantly augmenting,
their stellar disk in the outer, low-density environment.
Prior to
GALEX, such regions were considered to be far more stable
against star
formation than now realized. Our work on these targets has
led to the
recognition of the XUV phenomenon as probing a diverse
population of
galaxies which, although having certain commonality in
terms of their
present XUV star formation, have apparently experienced
different star
formation histories {as judged by their outer disk UV-
optical colors
and morphology}. In ordinary spirals, disk formation
occurred at a much
earlier epoch, making today's XUV-disks useful templates
for
commonplace, high z galaxies. The diverse XUV-disks in our
sample may
represent snapshots of different phases in the disk
building process. We
seek to characterize the demographics of star forming
regions occupying
this environmental range, especially in contrast to their
inner disk
counterparts. HST imaging is needed to accurately
characterize the
massive stars and clusters which have, in fact, managed to
form. The
GALEX observations are limited by 5" resolution. Deep
ACS FUV, B, V, I,
and H-alpha imaging {along with parallel WFPC2 data} will
allow: {1}
photometric classification of the
the cluster mass function and age distribution, {3}
critical accounting
for possible leakage of Lyman continuum photons in a
porous ISM or an
IMF change, and {4} population synthesis modeling of the
field SFH on
Gyr timescales. We benefit from extensive archival HST
observations of
our target galaxies, although the outer disk has yet to be
probed.
WFPC2 10890
Morphologies of the Most Extreme High-Redshift
Mid-IR-Luminous Galaxies
The formative phase 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,
restricting us to the study of 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 bright at mid-IR wavelengths
{F[24um]>0.8mJy}, but deep ground based imaging
suggests extremely faint
{and in some cases extended} optical counterparts
{R~24-27}. Deep K-band
images show barely resolved galaxies. Mid-infrared
spectroscopy with
Spitzer/IRS reveals that they have redshifts z ~ 2-2.5,
suggesting
bolometric luminosities ~10^{13-14}Lsun! We propose to
obtain deep ACS
F814W and NIC2 F160W images of these sources and their
environs in order
to determine kpc-scale morphologies and surface photometry
for these
galaxies. The proposed observations will help us determine
whether these
extreme objects are merging systems, massive obscured
starbursts {with
obscuration on kpc scales!} or very reddened {locally
obscured} AGN
hosted by intrinsically low-luminosity galaxies.
WFPC2 10880
The host galaxies of QSO2s: AGN feeding and evolution at
high
luminosities
Now that the presence of supermassive black holes in the
nuclei of
galaxies is a well established fact, other questions
related to the AGN
phenomena still have to be answered. Problems of
particular interest are
how the AGN gets fed, how the black hole evolves and how
the evolution
of the black hole is related to the evolution of the
galaxy bulge. Here
we propose to address some of these issues using ACS/WFC +
F775W
snapshot images of 73 QSO2s with redshifts in the range
0.3<z<0.4. These
observations will be combined with similar archival data
of QSO1s and
ground based data of Seyfert and normal galaxies. First,
we will
intestigate whether interactions are the most important
feeding
mechanism in high luminosity AGNs. This will be done in a
quantitative
way, comparing the asymmetry indices of QSO2 hosts with
those of lower
luminosity AGNs and normal galaxies. Second, we will do a
detailed study
of the morphology of the host galaxies of both QSO types,
to determine
if they are similar, or if there is an evolutionary trend
from QSO2s to
QSO1s. The results from this project will represent an
important step in
the understanding of AGN evolution, and may also introduce
a substantial
modification to the Unified Model.
WFPC2 10877
A Snapshot Survey of the Sites of Recent, Nearby
Supernovae
During the past few years, robotic {or nearly robotic}
searches for
supernovae {SNe}, most notably our Lick Observatory
Supernova Search
{LOSS}, have found hundreds of SNe, many of them in quite
nearby
galaxies {cz < 4000 km/s}. Most of the objects were
discovered before
maximum brightness, and have follow-up photometry and
spectroscopy; they
include some of the best-studied SNe to date. We propose
to conduct a
snapshot imaging survey of the sites of some of these
nearby objects, to
obtain late-time photometry that {through the shape of the
light and
color curves} will help reveal the origin of their
lingering energy. The
images will also provide high-resolution information on
the local
environments of SNe that are far superior to what we can
procure from
the ground. For example, we will obtain color-color and
color-magnitude
diagrams of stars in these SN sites, to determine the SN
progenitor
masses and constraints on the reddening. Recovery of the
SNe in the new
HST images will also allow us to actually pinpoint their
progenitor
stars in cases where pre- explosion images exist in the
HST archive.
This proposal is an extension of our successful Cycle 13
snapshot survey
with ACS. It is complementary to our Cycle 15 archival
proposal, which
is a continuation of our long-standing program to use
existing HST
images to glean information about SN environments.
NIC2 10858
NICMOS Imaging of the z ~ 2 Spitzer Spectroscopic Sample
of
Ultraluminous Infrared
We propose to obtain NICMOS images of the first large
sample of high-z
ultra-luminous infrared galaxies {ULIRGs} whose redshifts
and physical
states have been determined with Spitzer mid-IR spectra.
The detection
of strong silicate absorption and/or PAH emission lines
suggest that the
these sources are a mixture of highly obscured starbursts,
AGNs and
composite systems at z=2. Although some of the spectra
show PAH emission
similar to local starburst ULIRGs, their bolometric
luminosities are
roughly an order of magnitude higher. One important
question is if major
mergers, which are the trigger for 95% of local ULIRGs,
also drive this
enormous energy output observed in our z=2 sample. The
NICMOS images
will allow us to {1} measure surface brightness profiles
of z~2 ULIRGs
and establish if major mergers could be common among our
luminous
sources at these early epochs, {2} determine if starbursts
and AGNs
classified based on their mid-IR spetra would have
different
morphological signatures, thus different dynamic state;
{3} make
comparisons with the similar studies of ULIRGs at z ~ 0 -
1, thus infer
any evolutionary connections between high-z ULIRGs and the
formation of
normal, massive galaxies and quasars observed today.
WFPC2 10845
HUNTING FOR OPTICAL COMPANIONS TO BINARY MILLISECOND
PULSARS IN TERZAN 5
AND NGC6266
We propose deep WFPC2 and NICMOS observations to search
for optical
companions to binary millisecond pulsar {MSPs} in two
Globular Clusters
{GCs}: Terzan 5 and NGC6266. Terzan 5 has the largest MSP
population of
any GC: 33 MSP {17 in binary systems} have been discovered
up to now in
this stellar system. NGC6266 ranks fifth among the GC for
wealth of MSPs
but it is the only one in which all the {six} detected
MSPs are in
binary systems. Only 5 optical counterparts to binary MSP
companions are
known in GCs {two of them have been discovered by our
group}: hence even
the addition of a few new identifications are crucial to
investigate the
variety of processes occurring in binary MSPs in dense
environment. The
observations proposed here would easily double/triple the
existing
sample of known MSP companions, allowing the first
meaningful study of
the phenomena which drive the formation and evolution of
these exotic
systems. Moreover, since most of binary MSP in GC are
formed via stellar
interactions in the high density regions of the cluster,
the
determination of the nature of the companion and the
incidence of this
collisionally induced population have a significant impact
on our
knowledge of the cluster dynamics. Even more interesting,
the study of
the optical companions to NSs in a GC allows to derive
tighter
constraints {than those obtainable for NS binaries in the
galactic
field} on the properties {mass, orbital inclination and so
on} of the
compation star. This has, in turn, an intrisic importance
for
fundamental physics since it offers the opportunity of
measuring the
mass of the NS and hence to put constraints to the
equation of state of
matter at nuclear equilibrium density.
NIC3 10836
The Red Sequence at 1.3 < z < 1.4 in Galaxy Clusters
We propose to obtain NIC3/F160W imaging of three new
IRAC-selected
galaxy clusters at 1.3 < z < 1.5. In combination
with deep ACS/F850LP
images being obtained in Cycle 14, the resulting precision
photometry in
a rest ~U - R color will allow us to construct color-
magnitude diagrams
which can be used to measure the slope and scatter in the
red sequence
galaxies, thereby constraining the history of star
formation in the
early-type galaxies. The number of
morphologically-selected early-type
galaxies more luminous than L* will allow us to test the
predictions of
the hierarchical merging scenario for galaxy formation in
clusters at
the highest available redshifts in galaxy clusters.
WFPC2 10815
The Blue Hook Populations of Massive Globular Clusters
Blue hook stars are a class of hot {~35,000 K} subluminous
horizontal
branch stars that have been recently discovered using HST
ultraviolet
images of the globular clusters omega Cen and NGC 2808.
These stars
occupy a region of the HR diagram that is unexplained by
canonical
stellar evolution theory. Using new theoretical
evolutionary and
atmospheric models, we have shown that the blue hook stars
are very
likely the progeny of stars that undergo extensive
internal mixing
during a late helium core flash on the white dwarf cooling
curve. This
"flash mixing" produces an enormous enhancement
of the surface helium
and carbon abundances, which suppresses the flux in the
far ultraviolet.
Although flash mixing is more likely to occur in stars
that are born
with high helium abundances, a high helium abundance, by
itself, does
not explain the presence of a blue hook population - flash
mixing of the
envelope is required. We propose ACS ultraviolet {SBC/F150LP}
observations of the five additional globular clusters for
which the
presence of blue hook stars is suspected from longer
wavelength
observations. Like omega Cen and NGC 2808, these five
targets are also
among the most massive globular clusters, because less
massive clusters
show no evidence for blue hook stars. Because our targets
span 1.5 dex
in metallicity, we will be able to test our prediction
that flash-mixing
should be less drastic in metal-rich blue hook stars. In
addition, our
observations will test the hypothesis that blue hook stars
only form in
globular clusters massive enough to retain the
helium-enriched ejecta
from the first stellar generation. If this hypothesis is
correct, then
our observations will yield important constraints on the
chemical
evolution and early formation history in globular
clusters, as well as
the role of helium self-enrichment in producing blue
horizontal branch
morphologies and multiple main sequence turnoffs. Finally,
our
observations will provide new insight into the formation
of the hottest
horizontal branch stars, with implications for the origin
of the hot
helium-rich subdwarfs in the Galactic field.
NIC2 10798
Dark Halos and Substructure from Arcs & Einstein Rings
The surface brightness distribution of extended
gravitationally lensed
arcs and Einstein rings contains super-resolved
information about the
lensed object, and, more excitingly, about the smooth and
clumpy mass
distribution of the lens galaxies. The source and lens information
can
non-parametrically be separated, resulting in a direct
"gravitational
image" of the inner mass-distribution of
cosmologically-distant galaxies
{Koopmans 2005; Koopmans et al. 2006 [astro-ph/0601628]}.
With this goal
in mind, we propose deep HST ACS-F555W/F814W and
NICMOS-F160W WFC
imaging of 20 new gravitational-lens systems with
spatially resolved
lensed sources, of the 35 new lens systems discovered by
the Sloan Lens
ACS Survey {Bolton et al. 2005} so far, 15 of which are
being imaged in
Cycle-14. Each system has been selected from the SDSS and
confirmed in
two time- efficient HST-ACS snapshot programs {cycle
13&14}.
High-fidelity multi-color HST images are required {not
delivered by the
420s snapshots} to isolate these lensed images {properly
cleaned,
dithered and extinction-corrected} from the lens galaxy
surface
brightness distribution, and apply our "gravitational
maging" technique.
Our sample of 35 early-type lens galaxies to date is by
far the largest,
still growing, and most uniformly selected. This minimizes
selection
biases and small-number statistics, compared to smaller,
often
serendipitously discovered, samples. Moreover, using the
WFC provides
information on the field around the lens, higher S/N and a
better
understood PSF, compared with the HRC, and one retains
high spatial
resolution through drizzling. The sample of galaxy mass
distributions -
determined through this method from the arcs and Einstein
ring HST
images - will be studied to: {i} measure the smooth mass
distribution of
the lens galaxies {dark and luminous mass are separated
using the HST
images and the stellar M/L values derived from a joint
stellar-dynamical
analysis of each system}; {ii} quantify statistically and
individually
the incidence of mass-substructure {with or without
obvious luminous
counter- parts such as dwarf galaxies}. Since dark-matter
substructure
could be more prevalent at higher redshift, both results
provide a
direct test of this prediction of the CDM hierarchical
structure-formation model.
WFPC2 10786
Rotational state and composition of Pluto's outer
satellites
We propose an intricate set of observations aimed at
discovering the
rotational state of the newly discovered satellites of
Pluto, S/2005 P1
and S/2005 P2. These observations will indicate if the
satellites are in
synchronous rotation or not. If they are not, then the
observations will
determine the rotational period or provide tight
constraints on the
amplitude. The other primary goal is to extend the
wavelength coverage
of the colors of the surface and allow us to constrain the
surface
compositions of both objects. From these data we will also
be able to
significantly improve the orbits of P1 and P2, improve the
measurement
of the bulk density of Charon, and search for albedo
changes on the
surface of Pluto.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
10800 - GSAcq(1,2,1) failed to RGA Hold (Gyro Control)
GSACQ(1,2,2) at 126/05:37:26 failed to RGA control with QF1STOPF and
QSTOP flags set.
Subsequent REacq(1,2,1) scheduled at 125/17:22:30 using same star id
failed to RGA Hold due to search radius limit exceeded on FGS1.
10801 - GSACQ(1,2,2) failed
GSACQ(1,2,2) at 126/05:37:26 failed to RGA control with QF1STOPF and
QSTOP flags set.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
20
18
FGS
REacq
22
21
OBAD with Maneuver
84
84
SIGNIFICANT EVENTS: (None)