HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4525
PERIOD
COVERED: UT January 011, 2008 (DOY 011)
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 DARKs. 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
11339
A
deep observation of NGC4261: understanding its unique X-ray source
population,
gas morphology, and jet properties
The
nearby early-type galaxy NGC4261 reveals strikingly asymmetric
distributions
of X-ray sources as seen with Chandra, and globular
clusters
(GC) as seen in the optical band. To address the link between
these
populations based on their spatial correlation, luminosity
function
and spectral properties, and to investigate
the possibility
that
this effect is due to the galaxy's merger history, we propose a
100ksec
Chandra ACIS-S3 exposure, which will detect X-ray sources down
to
typical LMXB luminosities (Lx~5E37 erg/s), and HST-WFPC2 observations
to
obtain a deep census of the GC population over the whole galaxy.
These
data will also allow a detailed study of its complex gaseous
component,
and provide information on the unique two-sided X-ray jet.
WFPC2
11327
Red
leaks
The
aim of this program is to measure the red leaks in the 8 WFPC2 UV???
filters
(F122M, F300W, F255W, F218W, F185W, F170W, F160BW, F122M). We
will
use red crossing filters to isolate and directly measure the leaks.
No
observations of this kind have ever been performed with WFPC2 to
check
the red leaks in the UV filters, most of them being extensively
used
by GO/GTO programs. A previous calibration program has only imaged
spectrophotometric
standard stars with UV filters (no filter crossing)
thus
the red leak is hard to measure using this data. The throughput
curves
for some of the UV filters (F300W, F255W, F218W, F185W) in
synphot
have incomplete information, some of them have gaps in the
measurements
as wide as 3000A.
ACS/SBC
11225
The
Wavelength Dependence of Accretion Disk Structure
We
can now routinely measure the size of quasar accretion disks using
gravitational
microlensing of lensed quasars. The next step to testing
accretion
disk models is to measure the size of accretion disks as a
function
of wavelength, particularly at the UV and X-ray wavelengths
that
should probe the inner, strong gravity regime. Here we focus on two
four-
image quasar lenses that already have optical {R band} and X-ray
size
measurements using microlensing. We will combine the HST
observations
with ground-based monitoring to measure the disk size as a
function
of wavelength from the near-IR to the UV. We require HST to
measure
the image flux ratios in the ultraviolet continuum near the
Lyman
limit of the quasars. The selected targets have estimated black
hole
masses that differ by an order of magnitude, and we should find
wavelength
scalings for the two systems that are very different because
the
Blue/UV wavelengths should correspond to parts of the disk near the
inner
edge for the high mass system but not in the low mass system. The
results
will be modeled using a combination of simple thin disk models
and
complete relativistic disk models. While requiring only 18 orbits,
success
for one system requires observations in both Cycles 16 and 17.
WFPC2
11217
The
Light Echoes around V838 Monocerotis
V838
Monocerotis, which burst upon the astronomical scene in early 2002,
is
a completely unanticipated new object. It underwent a large-amplitude
and
very luminous outburst, during which its spectrum remained that of
an
extremely cool supergiant. A rapidly evolving set of light echoes
around
V838 Mon was discovered soon after the outburst, and quickly
became
the most spectacular display of the phenomenon ever seen. These
light
echoes provide the means to accomplish three unique types of
measurements
based on continued HST imaging during the event: {1} Study
effects
of MHD turbulence at high resolution and in 3 dimensions; {2}
Construct
the first unambiguous and fully 3-D map of a circumstellar
dust
envelope in the Milky Way; {3} Study dust physics in a unique
setting
where the spectrum and light curve of the illumination, and the
scattering
angle, are unambiguously known. We have also used our HST
data
to determine the distance to V838 Mon through direct geometric
techniques.
Because of the extreme rarity of light echoes, this is
almost
certainly the only opportunity to achieve such results during the
lifetime
of HST. We propose two visits during Cycle 16, in order to
continue
the mapping of the circumstellar dust and to accomplish the
other
goals listed above.
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.
FGS
11212
Filling
the Period Gap for Massive Binaries
The
current census of binaries among the massive O-type stars is
seriously
incomplete for systems in the period range from years to
millennia
because the radial velocity variations are too small and the
angular
separations too close for easy detection. Here we propose to
discover
binaries in this observational gap through a Faint Guidance
Sensor
SNAP survey of relatively bright targets listed in the Galactic O
Star
Catalog. Our primary goal is to determine the binary frequency
among
those in the cluster/association, field, and runaway groups. The
results
will help us assess the role of binaries in massive star
formation
and in the processes that lead to the ejection of massive
stars
from their natal clusters. The program will also lead to the
identification
of new, close binaries that will be targets of long term
spectroscopic
and high angular resolution observations to determine
their
masses and distances. The results will also be important for the
interpretation
of the spectra of suspected and newly identified binary
and
multiple systems.
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 W Vir
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/NIC3
11144
Building
on the Significant NICMOS Investment in GOODS: A Bright,
Wide-Area
Search for z>=7 Galaxies
One
of the most exciting frontiers in observational cosmology has been
to
trace the buildup and evolution of galaxies from very early times.
While
hierarchical theory teaches us that the star formation rate in
galaxies
likely starts out small and builds up gradually, only recently
has
it been possible to see evidence for this observationally through
the
evolution of the LF from z~6 to z~3. Establishing that this build up
occurs
from even earlier times {z~7-8} has been difficult, however, due
to
the small size of current high-redshift z~7-8 samples -- now
numbering
in the range of ~4-10 sources. Expanding the size of these
samples
is absolutely essential, if we are to push current studies of
galaxy
buildup back to even earlier times. Fortunately, we should soon
be
able to do so, thanks to ~50 arcmin**2 of deep {26.9 AB mag at 5
sigma}
NICMOS 1.6 micron data that will be available over the two ACS
GOODS
fields as a result of one recent 180-orbit ACS backup program and
a
smaller program. These data will nearly triple the deep near-IR
imaging
currently available and represent a significant resource for
finding
and characterizing the brightest high-redshift sources -- since
high-redshift
candidates can be easily identified in these data from
their
red z-H colours. Unfortunately, the red z-H colours of these
candidates
are not sufficient to determine that these sources are at
z>=7,
and it is important also to have deep photometry at 1.1 microns.
To
obtain this crucial information, we propose to follow up each of
these
z-H dropouts with NICMOS at 1.1 microns to determine which are at
high
redshift and thus significantly expand our sample of luminous, z>=7
galaxies.
Since preliminary studies indicate that these candidates occur
in
only 30% of the NIC3 fields, our follow-up strategy is ~3 times as
efficient
as without this preselection and 9 times as efficient as a
search
in a field with no pre-existing data. In total, we expect to
identify
~8 luminous z-dropouts and possibly ~2 z~10 J-dropouts as a
result
of this program, more than tripling the number currently known.
The
increased sample sizes are important if we are to solidify current
conclusions
about galaxy buildup and the evolution of the LF from z~8.
In
addition to the high redshift science, these deep 1.1 micron data
would
have significant value for many diverse endeavors, including {1}
improving
our constraints on the stellar mass density at z~7-10 and {2}
doubling
the number of galaxies at z~6 for which we can estimate dust
obscuration.
NIC2
11142
Revealing
the Physical Nature of Infrared Luminous Galaxies at 0.3
We
aim to determine physical properties of IR luminous galaxies at
0.3<z<2.7
by requesting coordinated HST/NIC2 and MIPS 70um observations
of
a unique, 24um flux-limited sample with complete Spitzer mid-IR
spectroscopy.
The 150 sources investigated in this program have S{24um}
>
0.8mJy and their mid-IR spectra have already provided the majority
targets
with spectroscopic redshifts {0.3<z<2.7}. The proposed
150~orbits
of NIC2 and 66~hours of MIPS 70um will provide the physical
measurements
of the light distribution at the rest-frame ~8000A and
better
estimates of the bolometric luminosity. Combining these
parameters
together with the rich suite of spectral diagnostics from the
mid-IR
spectra, we will {1} measure how common mergers are among LIRGs
and
ULIRGs at 0.3<z<2.7, and establish if major mergers are the drivers
of
z>1 ULIRGs, as in the local Universe. {2} study the co-evolution of
star
formation and blackhole accretion by investigating the relations
between
the fraction of starburst/AGN measured from mid-IR spectra vs.
HST
morphologies, L{bol} and z. {3} obtain the current best estimates of
the
far-IR emission, thus L{bol} for this sample, and establish if the
relative
contribution of mid-to-far IR dust emission is correlated with
morphology
{resolved vs. unresolved}.
WFPC2
11127
Mapping
the nebula surrounding the enigmatic X-ray source at the center
of
the Vela Jr SNR
A
compact X-ray source, showing nothing but steady unpulsed thermal
emission,
lies close to the center of the young and nearby supernova
remnant
dubbed "Vela Jr". It is a typical member of a class of enigmatic
sources,
supposed to be the youngest members of the radio-quiet neutron
star
family. Quite surprisingly, we discovered in ground-based optical
observations
a small Halpha nebula spatially coincident with the X-ray
source.
Such a nebula potentially carries very important information on
the
nature of the X-ray source, which remains elusive in spite of large
observational
efforts. We propose to use the WFPC2 to collect high
resolution
Halpha images of the nebula in order to resolve its
structure,
to understand its nature, and to identify its connection with
the
X-ray source. Addressing all these points will also have important
implications
for our interpretation of the compact X-ray source and on
of
other objects of the same class.
NIC3
11107
Imaging
of Local Lyman Break Galaxy Analogs: New Clues to Galaxy
Formation
in the Early Universe
We
have used the ultraviolet all-sky imaging survey currently being
conducted
by the Galaxy Evolution Explorer {GALEX} to identify for the
first
time a rare population of low-redshift starbursts with properties
remarkably
similar to high-redshift Lyman Break Galaxies {LBGs}. These
"compact
UV luminous galaxies" {UVLGs} resemble LBGs in terms of size,
SFR,
surface brightness, mass, metallicity, kinematics, dust, and color.
The
UVLG sample offers the unique opportunity of investigating some very
important
properties of LBGs that have remained virtually inaccessible
at
high redshift: their morphology and the mechanism that drives their
star
formation. Therefore, in Cycle 15 we have imaged 7 UVLGs using ACS
in
order to 1} characterize their morphology and look for signs of
interactions
and mergers, and 2} probe their star formation histories
over
a variety of timescales. The images show a striking trend of
small-scale
mergers turning large amounts of gas into vigorous
starbursts
{a process referred to as dissipational or "wet" merging}.
Here,
we propose to complete our sample of 31 LBG analogs using the
ACS/SBC
F150LP {FUV} and WFPC2 F606W {R} filters in order to create a
statistical
sample to study the mechanism that triggers star formation
in
UVLGs and its implications for the nature of LBGs. Specifically, we
will
1} study the trend between galaxy merging and SFR in UVLGs, 2}
artificially
redshift the FUV images to z=1-4 and compare morphologies
with
those in similarly sized samples of LBGs at the same rest-frame
wavelengths
in e.g. GOODS, UDF, and COSMOS, 3} determine the presence
and
morphology of significant stellar mass in "pre-burst" stars, and 4}
study
their immediate environment. Together with our Spitzer
{IRAC+MIPS},
GALEX, SDSS and radio data, the HST observations will form
a
unique union of data that may for the first time shed light on how the
earliest
major episodes of star formation in high redshift galaxies came
about.
This proposal was adapted from an ACS HRC+WFC proposal to meet
the
new Cycle 16 observing constraints, and can be carried out using the
ACS/SBC
and WFPC2 without compromising our original science goals.
NIC3
11082
NICMOS
Imaging of GOODS: Probing the Evolution of the Earliest Massive
Galaxies,
Galaxies Beyond Reionization, and the High Redshift Obscured
Universe
(uses
ACS/SBC and WFPC2)
Deep
near-infrared imaging provides the only avenue towards
understanding
a host of astrophysical problems, including: finding
galaxies
and AGN at z > 7, the evolution of the most massive galaxies,
the
triggering of star formation in dusty galaxies, and revealing
properties
of obscured AGN. As such, we propose to observe 60 selected
areas
of the GOODS North and South fields with NICMOS Camera 3 in the
F160W
band pointed at known massive M > 10^11 M_0 galaxies at z > 2
discovered
through deep Spitzer imaging. The depth we will reach {26.5
AB
at 5 sigma} in H_160 allows us to study the internal properties of
these
galaxies, including their sizes and morphologies, and to
understand
how scaling relations such as the Kormendy relationship
evolved.
Although NIC3 is out of focus and undersampled, it is currently
our
best opportunity to study these galaxies, while also sampling enough
area
to perform a general NIR survey 1/3 the size of an ACS GOODS field.
These
data will be a significant resource, invaluable for many other
science
goals, including discovering high redshift galaxies at z > 7,
the
evolution of galaxies onto the Hubble sequence, as well as examining
obscured
AGN and dusty star formation at z > 1.5. The GOODS fields are
the
natural location for HST to perform a deep NICMOS imaging program,
as
extensive data from space and ground based observatories such as
Chandra,
GALEX, Spitzer, NOAO, Keck, Subaru, VLT, JCMT, and the VLA are
currently
available for these regions. Deep high-resolution
near-infrared
observations are the one missing ingredient to this
survey,
filling in an important gap to create the deepest, largest, and
most
uniform data set for studying the faint and distant universe. The
importance
of these images will increase with time as new facilities
come
on line, most notably WFC3 and ALMA, and for the planning of future
JWST
observations.
NIC1
11057
Cycle
15 NICMOS dark current, shading profile, and read noise monitoring
program
The
purpose of this proposal is to monitor the dark current, read noise,
and
shading profile for all three NICMOS detectors throughout the
duration
of Cycle 15. This proposal is a slightly modified version of
proposal
10380 of cycle 13 and 9993 of cycle12 and is the same as Cycle
14.
that we cut down some exposure time to make the observation fit
within
24 orbits.
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
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.
NIC3
10874
Search
for Extremely Faint z>7 Galaxy Population with Cosmic Lenses
Deep
UDF/NICMOS observations find a significant decrease in the number
of
galaxy candidates between redshift z=6 and 7, but the sample at z>7
is
too small to draw conclusions. From our observations of 15 clusters
we
have found a number of bright z-dropouts, aided by the lensing
amplification.
We propose deep NICMOS observations of the best cases of
cluster
centers where a rare combination of a significant lensing effect
and
the richness in z-band dropouts in background may dramatically
increase
the discovery rate. The NICMOS images will reach an
unprecedented depth of
AB~27.8, or AB~30 in nonlensed intrinsic
magnitude,
and may find many faint {~0.05L*} galaxies at z=7-10, at a
level
that the UDF reaches for z~6 objects. We produce precision mass
distribution
maps from weak-lensing models, which enable us to derive
the
candidates' intrinsic magnitudes and their luminosity function. The
knowledge
of such faint galaxy population at z>7 will facilitate the
models
of the IGM reionization and future JWST planning.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
11141
- REAcq (1,2,1) failed to RGA Hold
At 014/03:17:03, REAcq (1,2,1) scheduled from 03:13:33 - 03:20:34
failed
to RGA Hold. Received both QF2STOPF & QSTOP flags.
Pre-acquisition OBAD
#1 RSS = 1075.68 a-s. Pre-acquisition OBAD #2 RSS = 12.67 a-s.
Post-acquisition OBAD MAP was not scheduled. FGS 2 achieved
finelock at
03:16:51 but, lost it at 03:17:01.
11142
- REAcq (1,2,1) resulted in fine lock back-up (1,0,1)
REAcq (1,2,1) scheduled from 014/08:52:14 - 08:59:29 resulted in
fine
lock back-up (1,0,1) using FGS 1. Received QF2STOPF & QSTOP
flags.
Pre-acquisition OBAD #1 data unavailable due to a scheduled loss
of
signal. Pre-acquisition OBAD #2 RSS = 8.37 a-s. Post-acquisition
OBAD
MAP RSS = 9.41 a-s.
COMPLETED
OPS REQUEST:
18170-1
- Uplink new FGS Alignment and Calibration tables
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
19
19
FGS
REacq
20
19
OBAD
with Maneuver 78
78
SIGNIFICANT
EVENTS:
OPS
Flash Report:
The
FGS Alignment and Calibration table uplink
activity
scheduled for 014/00:15 was successfully completed. The guide
star
acquisition at 01:37 was nominal.