HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #4681
PERIOD COVERED: 5am August 22 - 5am August 25, 2008 (DOY
235/0900z-238/0900z)
OBSERVATIONS SCHEDULED
SIGNIFICANT EVENTS: (None)
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.
NIC2 11548
NICMOS Imaging of Protostars in the Orion A Cloud: The
Role of
Environment in Star Formation
We propose NICMOS observations of a sample of 252
protostars identified
in the Orion A cloud with the Spitzer Space Telescope.
These
observations will image the scattered light escaping the
protostellar
envelopes, providing information on the shapes of outflow
cavities, the
inclinations of the protostars, and the overall
morphologies of the
envelopes. In addition, we ask for Spitzer time to obtain
55-95 micron
spectra of 75 of the protostars. Combining these new data
with existing
3.6 to 70 micron photometry and forthcoming 5-40 micron
spectra measured
with the Spitzer Space Telescope, we will determine the
physical
properties of the protostars such as envelope density,
luminosity,
infall rate, and outflow cavity opening angle. By
examining how these
properties vary with stellar density (i.e. clusters vs
groups vs
isolation) and the properties of the surrounding molecular
cloud; we can
directly measure how the surrounding environment
influences protostellar
evolution, and consequently, the formation of stars and
planetary
systems. Ultimately, this data will guide the development
of a theory of
protostellar evolution.
NIC3 11545
A NICMOS Survey of Newly-Discovered Young Massive Clusters
We are on the cusp of a revolution in massive star
research triggered by
2MASS and Spitzer/GLIMPSE, and now is the ideal time to
capitalize on
these projects by performing the first survey of massive
stars in young
stellar clusters throughout the Galactic plane. A search
of the 2MASS
and GLIMPSE surveys has produced over 450 newly-identified
massive
stellar cluster candidates in the Galactic plane which are
hidden from
our view at optical wavelengths due to extinction. Here we
propose a
program of 29 orbits to image the most promising candidate
clusters in
broad and narrow band filters using HST/NICMOS. We will be
complementing
these observations with approved Spitzer and Chandra
programs,
numerous approved and planned ground-based spectroscopic
observations,
and state-of-the-art modeling. We expect to substantially
increase the
numbers of massive stars known in the Galaxy, including
main sequence
stars and post-main sequence stars in the Red Supergiant,
Luminous Blue
Variable and Wolf-Rayet stages. Ultimately, this program
will address
many of the fundamental topics in astrophysics: the slope
to the initial
mass function (IMF), an upper-limit to the masses of
stars, the
formation and evolution of the most massive stars,
gamma-ray burst (GRB)
progenitors, the chemical enrichment of the interstellar
medium, and
nature of the first stars in the Universe.
NIC1/NIC2/NIC3 11330
NICMOS Cycle 16 Extended Dark
This takes a series of Darks in parallel to other
instruments.
ACS/SBC 11322
BEA UV Contamination Monitor
The observations consist of imaging and spectroscopy with
ACS/SBC of the
scaled
with the F122M, F150LP, F165LP filters and the PR130L
prism. The
observations will allow any UV contamination to be
monitored by
comparing these data with identical observations to be
obtaining during
the BEA phase of SMOV4. Also included are a suite of
internal Deuterium
lamp flat fields to be acquired shortly before the
servicing mission for
comparison with exactly the same set to be acquired in
SMOV/11398.
WFPC2 11218
Snapshot Survey for Planetary Nebulae in Globular Clusters
of the Local
Group
Planetary nebulae {PNe} in globular clusters {GCs} raise a
number of
interesting issues related to stellar and galactic
evolution. The number
of PNe known in Milky Way GCs, 4, is surprisingly low if
one assumes
that all stars pass through a PN stage. However, it is
likely that the
remnants of stars now evolving in Galactic GCs leave the
AGB so slowly
that any ejected nebula dissipates long before the star
becomes hot
enough to ionize it. Thus there should not be ANY PNe in
Milky Way
GCs--but there are four! It has been suggested that these
PNe are the
result of mergers of binary stars within GCs, i.e., that
they are
descendants of blue stragglers. The frequency of
occurrence of PNe in
external galaxies poses more questions, because it shows a
range of
almost an order of magnitude. I propose a Snapshot survey
aimed at
discovering PNe in the GC systems of Local Group galaxies
more distant
than the Magellanic Clouds. These clusters, some of which
may be much
younger than their counterparts in the Milky Way, might
contain many
more PNe than those of our own galaxy. I will use the
standard technique
of emission-line and continuum imaging, which easily
discloses PNe.
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.
NIC1 11205
The Effects of Multiplicity on the Evolution of Young
Stellar Objects: A
NICMOS Imaging Study
We propose to use NICMOS to investigate the multiplicity
of young
stellar objects (YSOs) in the Orion B molecular cloud.
Previous
observations with the Spitzer Space Telescope have
revealed a remarkable
star forming filament near the NGC 2068 reflection nebula.
The
population of YSOs associated with the filament exhibit a
surprisingly
wide range of circumstellar evolutionary states, from
deeply embedded
protostars to T Tauri accretion disks. Many of the circumstellar
disks
themselves show evidence for significant dust evolution,
including grain
growth and settling and cleared inner holes, apparently in
spite of the
very young age of these stars. We will estimate the binary
fraction of a
representative sample of objects in these various stages
of evolution in
order to test whether companions may play a significant
role in that
evolution.
WFPC2 11178
Probing Solar System History with Orbits, Masses, and
Colors of
Transneptunian Binaries
The recent discovery of numerous transneptunian binaries
{TNBs} opens a
window into dynamical conditions in the protoplanetary
disk where they
formed as well as the history of subsequent events which
sculpted the
outer Solar System and emplaced them onto their present
day heliocentric
orbits. To date, at least 47 TNBs have been discovered,
but only about a
dozen have had their mutual orbits and separate colors
determined,
frustrating their use to investigate numerous important
scientific
questions. The current shortage of data especially
cripples scientific
investigations requiring statistical comparisons among the
ensemble
characteristics. We propose to obtain sufficient
astrometry and
photometry of 23 TNBs to compute their mutual orbits and
system masses
and to determine separate primary and secondary colors,
roughly tripling
the sample for which this information is known, as well as
extending it
to include systems of two near-equal size bodies. To make
the most
efficient possible use of HST, we will use a
optimally schedule our observations.
NIC1/NIC2 11172
Defining Classes of Long Period Variable Stars in M31
We propose a thrifty but information-packed investigation
{1440
exposures total} with NICMOS F205W, F160W and F110W
providing crucial
information about Long Period Variables in M31, at a level
of detail
that has recently allowed the discovery of new variable
star classes in
the Magellanic Clouds, a very different stellar
population. These
observations are buttressed by an extensive map of the
same fields with
ACS and WFPC2 exposures in F555W and F814W, and a massive
ground-based
imaging patrol producing well-sampled light curves for
more than 400,000
variable stars. Our primary goal is to collect sufficient
NIR data in
order to analyze and classify the huge number of
long-period variables
in our catalog {see below} through Period-Luminosity {P/L}
diagrams. We
will produce accurate P/L diagrams for both the bulge and
a progression
of locations throughout the disk of M31. These diagrams will
be similar
in quality to those currently in the Magellanic Clouds,
with their lower
metallicity, radically different star formation history,
and larger
spread in distance to the variables. M31 offers an
excellent chance to
study more typical disk populations, in a manner which
might be extended
to more distant galaxies where such variables are still
visible, probing
a much more evenly spread progenitor age distribution than
cepheids {and
perhaps useful as a distance scale alternative or
cross-check}. Our data
will also provide a massive and unique color-magnitude
dataset, and
allow us to confirm the microlensing nature of a large
sample of
candidate lensed sources in M31. We expect that this study
will produce
several important results, among them a better
understanding of P/L and
P/L-color relations for pulsating variables which are
essential to the
extragalactic distance ladder, will view these variables
at a common
distance over a range of metallicities {eliminating the
distance- error
vs. metallicity ambiguity between the LMC and SMC}, allow
further
insight into possible faint-variable mass-loss for higher
metallicities,
and in general produce a sample more typical of giant disk
galaxies
predominant in many studies.
NIC2 11157
NICMOS Imaging Survey of Dusty Debris Around Nearby Stars
Across the
Stellar Mass Spectrum
Association of planetary systems with dusty debris disks
is now quite
secure, and advances in our understanding of planet
formation and
evolution can be achieved by the identification and
characterization of
an ensemble of debris disks orbiting a range of central
stars with
different masses and ages. Imaging debris disks in
starlight scattered
by dust grains remains technically challenging so that
only about a
dozen systems have thus far been imaged. A further advance
in this field
needs an increased number of imaged debris disks. However,
the technical
challenge of such observations, even with the superb
combination of HST
and NICMOS, requires the best targets. Recent HST imaging
investigations
of debris disks were sample-limited not limited by the
technology used.
We performed a search for debris disks from a
IRAS/Hipparcos cross
correlation which involved an exhaustive background
contamination check
to weed out false excess stars. Out of ~140 identified
debris disks, we
selected 22 best targets in terms of dust optical depth
and disk angular
size. Our target sample represents the best currently
available target
set in terms of both disk brightness and resolvability.
For example, our
targets have higher dust optical depth, in general, than
newly
identified Spitzer disks. Also, our targets cover a wider
range of
central star ages and masses than previous debris disk
surveys. This
will help us to investigate planetary system formation and
evolution
across the stellar mass spectrum. The technical
feasibility of this
program in two-gyro mode guiding has been proven with
on-orbit
calibration and science observations during HST cycles 13,
14, and 15.
WFPC2 11130
AGNs with Intermediate-mass Black Holes: Testing the Black
Hole-Bulge
Paradigm, Part II
The recent progress in the study of central black holes in
galactic
nuclei has led to a general consensus that supermassive
{10^6-10^9 solar
mass} black holes are closely connected with the formation
and
evolutionary history of large galaxies, especially their
bulge
component. Two outstanding issues, however, remain
unresolved. Can
central black holes form in the absence of a bulge? And
does the mass
function of central black holes extend below 10^6 solar
masses?
Intermediate-mass black holes {<10^6 solar masses}, if
they exist, may
offer important clues to the nature of the seeds of
supermassive black
holes. Using the SDSS, our group has successfully
uncovered a new
population of AGNs with intermediate-mass black holes that
reside in
low-luminosity galaxies. However, very little is known
about the
detailed morphologies or structural parameters of the host
galaxies
themselves, including the crucial question of whether they
have bulges
or not. Surprisingly, the majority of the targets of our
Cycle 14 pilot
program have structural properties similar to dwarf
elliptical galaxies.
The statistics from this initial study, however, are
really too sparse
to reach definitive conclusions on this important new
class of black
holes. We wish to extend this study to a larger sample, by
using the
Snapshot mode to obtain WFPC2 F814W images from a parent
sample of 175
AGNs with intermediate- mass black holes selected from our
final SDSS
search. We are particularly keen to determine whether the
hosts contain
bulges, and if so, how the fundamental plane properties of
the host
depend on the mass of their central black holes. We will
also
investigate the environment of this unique class of AGNs.
WFPC2 11113
Binaries in the Kuiper Belt: Probes of Solar System
Formation and
Evolution
The discovery of binaries in the Kuiper Belt and related
small body
populations is powering a revolutionary step forward in
the study of
this remote region. Three quarters of the known binaries
in the Kuiper
Belt have been discovered with HST, most by our snapshot
surveys. The
statistics derived from this work are beginning to yield
surprising and
unexpected results. We have found a strong concentration
of binaries
among low-inclination Classicals, a possible size cutoff
to binaries
among the Centaurs, an apparent preference for nearly
equal mass
binaries, and a strong increase in the number of binaries
at small
separations. We propose to continue this successful
program in Cycle 16;
we expect to discover at least 13 new binary systems,
targeted to
subgroups where these discoveries can have the greatest
impact.
NIC2 11101
The Relevance of Mergers for Fueling AGNs: Answers from
QSO Host
Galaxies
The majority of QSOs are known to reside in centers of
galaxies that
look like ellipticals. Numerical simulations have shown
that remnants of
galaxy mergers often closely resemble elliptical galaxies.
However, it
is still strongly debated whether the majority of QSO host
galaxies are
indeed the result of relatively recent mergers or whether
they are
completely analogous to inactive ellipticals to which
nothing
interesting has happened recently. To address this
question, we recently
obtained deep HST ACS images for five QSO host galaxies
that were
classified morphologically as ellipticals {GO-10421}. This
pilot study
revealed striking signs of tidal interactions such as
ripples, tidal
tails, and warped disks that were not detected in previous
studies. Our
observations show that at least some
"elliptical" QSO host galaxies are
the products of relatively recent merger events rather
than old galaxies
formed at high redshift. However, the question remains
whether the host
galaxies of classical QSOs are truly distinct from
inactive ellipticals
and whether there is a connection between the merger
events we detect
and the current nuclear activity. We must therefore place
our results
into a larger statistical context. We are currently
conducting an HST
archival study of inactive elliptical galaxies {
control sample. We now propose to obtain deep HST/WFPC2
images of 13
QSOs whose host galaxies are classified as normal
ellipticals. Comparing
the results for both samples will help us determine
whether classical
QSOs reside in normal elliptical galaxies or not. Our
recent pilot study
of five QSOs indicates that we can expect exciting results
and deep
insights into the host galaxy morphology also for this
larger sample of
QSOs. A statistically meaningful sample will help us
determine the true
fraction of QSO hosts that suffered strong tidal
interactions and thus,
whether a merger is indeed a requirement to trigger
nuclear activity in
the most luminous AGNs. In addition to our primary science
observations
with WFPC2, we will obtain NICMOS3 parallel observations
with the
overall goal to select and characterize galaxy populations
at high
redshifts. The imaging will be among the deepest NICMOS
images: These
NICMOS images are expected to go to a limit a little over
1 magnitude
brighter than HUDF-NICMOS data, but over 13 widely
separated fields,
with a total area about 1.5 times larger than HUDF-
NICMOS. This
separation means that the survey will tend to average out
effects of
cosmic variance. The NICMOS3 images will have sufficient
resolution for
an initial characterization of galaxy morphologies, which
is currently
one of the most active and promising areas in approaching
the problem of
the formation of the first massive galaxies. The depth and
area coverage
of our proposed NICMOS observations will also allow a
careful study of
the mass function of galaxies at these redshifts. This
provides a large
and unbiased sample, selected in terms of stellar mass and
unaffected by
cosmic variance, to study the on-going star formation
activity as a
function of mass {i.e. integrated star formation} at this
very important
epoch.
NIC3 11072
Measuring the Physical Properties of the First Two WASP
Transiting
Extrasolar Planets
We have recently discovered the first two transiting
extrasolar planets
from the Wide Angle Search for Planets {WASP} project and
confirmed both
as planets using SOPHIE radial velocity measurements. Both
WASP-1b and
WASP-2b orbit about stars brighter than V=12, and are thus
ideal targets
for HST follow up. WASP-1b is probably inflated in a
manner similar to
HD209458b but is in a closer orbit about the parent, which
itself is the
earliest-type parent star yet announced for a transiting
extrasolar
planet. At 0.03 AU from the parent star, WASP-2b is close
to the minimum
separation at which planets of this mass range are thought
to survive.
We request DD observations of WASP-1b and WASP-2b, to
constrain the
masses and radii of both objects to a precision of a few
tenths of a
percent. Both parent stars have very similar brightnesses
to the TrES-1
parent star, thus we will achieve equivalent photometric
precision to
previous successful observations of TrES-1b. As all
further physical
investigations {such as interior heating} depend on
precise mass- and
radius-determinations, this investigation is the essential
next step in
uncovering the physical characteristics of these planets
and their
parent stars. We have requested 12 orbits, though 9 orbits
would provide
the minimum acceptable coverage for our program. The
consortium will
formally announce the discoveries of WASP-1b and WASP-2b
on Tuesday 26th
September 2006. We ask that all material in this proposal
be kept
confidential until that date. We can supply the discovery
paper on
request after this date.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
11450 - GSACQ(1,2,2) fails
Upon acquisition of signal at 236/12:42:46 vehicle was in
gyro control,
GSACQ(1,2,2) at 12:29:29 did not acquire fine lock. #44
commands did not
change since previous acquisition.
REACQ(1,2,2) at 14:05:16 was successful.
Observations affected: NICMOS 89 to 96, proposal 11545.
11451 - GSACQ(1,3,3) failed while LOS
Upon acquisition of signal at 236/19:31:45 vehicle was in gyro control,
GSACQ(1,3,3) at 236/19:25:49 failed while vehicle was LOS.
Observations affected: NICMOS 110 to 113, proposal 11548.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq
31
29
FGS
REacq
12
12
OBAD with Maneuver
86
86
SIGNIFICANT EVENTS: (None)