HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT #4774
PERIOD COVERED: 5am January 16 - 5am January 21, 2009 (DOY
016/1000z-021/1000z)
OBSERVATIONS SCHEDULED
WFPC2 11968
The Light Echoes Around V838 Monocerotis: Cycle 16 DD
This is a DD program in which we propose to obtain WFPC2
imaging of the
light echo around V838 Mon in late 2008 or early 2009. We
were awarded
Cycle 17 time to image the echo with ACS at 2 epochs (3+4
orbits). To
obtain data of similar quality with WFPC2 requires 7
orbits at 2
different pointings. Because of the SM4 delay, we are
therefore
requesting a 14-orbit DD program for Cycle 16, leaving the
Cycle 17
allocation unchanged for continued monitoring of the event
in late 2009
and 2010.
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,
quickly becoming
the most spectacular display of the phenomenon yet seen.
These light
echoes provide the means to accomplish three unique types
of
measurements based on continued HST imaging: (1) study MHD
turbulence at
high resolution and in 3 dimensions; (2) construct the
first unambiguous
and fully 3-D map of a circumstellar dust envelope; (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 a
novel geometric technique.
Because of the extreme rarity of light echoes, this
program of regular
monitoring provides the only opportunity to achieve such
results during
the HST lifetime. We propose WFPC2 imaging in late
2008/early 2009, in
order to continue the mapping of the circumstellar dust
and to
accomplish the other goals listed above.
WFPC2 11966
The Recent Star Formation History of SINGS Galaxies
The Spitzer Legacy project SINGS provided a unique view of
the current
state of star formation and dust in a sample of galaxies
of all Hubble
types. This multi-wavelength view allowed the team to
create current
star formation diagnostics that are independent of the
dust content and
increased our understanding of the dust in galaxies. Even
so, using the
SINGS data alone we can only make rough estimates of the
recent star
formation history of these galaxies. The lack of high
resolution
observations (especially U-band and H-alpha) means that it
is impossible
to estimate the ages of young clusters. In addition, the
low resolution
of the Spitzer and ground-based observations means that
what appear to
be individual Spitzer sources can actually be composed of
many
individual clusters with varying ages. We need to know the
ages, star
formation histories, and extinction of these individual
clusters to
understand how these clusters form and age and thus
influence the
evolution of the galaxy. In this proposal we address this
missing area
of SINGS by obtaining high-resolution WFPC2 UBVI &
H-alpha observations
to not only accurately locate and determine the ages of
the young
stellar clusters in the actively star forming SINGS
galaxies but to also
address a variety of other scientific issues. Over 500 HST
orbits and
500 hours of Spitzter observing time have been dedicated
to observations
of the SINGS sample. But the HST observations have not
been systematic.
By adding a relatively small fraction of this time for
these requested
observations, we will greatly enhance the legacy value of
the SINGS
observations by creating a uniform high resolution
multi-wavelength HST
archive that matches the quality of the lower resolution
SINGS archive.
WFPC2 11962
A New Supernova in the Antennae; Narrowing in on the
Hubble Constant and
Dark Energy
A measurement of the Hubble constant to a precision of a
few percent
would be a powerful aid to the investigation of the nature
of dark
energy and a potent "end-to-end" test of the
present cosmological model.
In Cycle 15 we constructed a new, streamlined distance
ladder utilizing
high-quality type Ia supernova data and observations of
Cepheids with
HST in the near-IR to minimize the dominant sources of
systematic
uncertainty in past measurements of the Hubble constant
and reduce its
total uncertainty to a little under 5%. Here we propose to
exploit this
new route with a rare opportunity to begin reducing the
remaining
uncertainty. SN 2007sr in the Antennae (NGC 4038/9) is the
rare SN Ia
which is suitable for increasing the precision of small
calibration
sample of
Cepheids are within range of observing with WFPC2 (and
NICMOS, should it
return to life). But we need to act fast as the window of
long
visibility and fixed orient runs from mid-early December
2008 to early
March 2009. We request 34 orbits with WFPC2 to find the Cepheids
in the
SN host. We also request 16 orbits to observe the Cepheids
we find with
Camera 2, F160W if NICMOS becomes available by April 2009
. (If NICMOS
does not return we would forgo these observations and ask
the TTRB to
let us make them with our own WFC3-IR allocation, though
we much prefer
the smaller pixel size of NIC2).
WFPC2 11956
Hubble Heritage: Side B
We propose a program of 39 orbits to observe 6 targets
with WFPC2
following a successful return to science using side B
electronics. These
observations will be used for Hubble Heritage releases in
the months
leading up to servicing mission 4. Because of launch
delays, our reserve
of releasable images is growing dangerously slim. We are
proposing here
to replenish one of our important lines of communication
with the
public.
We have carefully chosen targets that can efficiently use
single
pointings of WFPC2 to obtain images of visually striking
and
astrophysically interesting targets. Observations will reach
high S/N
and will be dithered and subsampled to improve the
resolution and pixel
scale to near ACS/WFC3 quality at a modest cost in
exposure time. Most
of the observations will schedule in the interim between a
return to
science and the availability of new science proposals that
may be
selected in response to an interim call for proposals.
WFPC2 11944
Binaries at the Extremes of the H-R Diagram
We propose to use HST/Fine Guidance Sensor 1r to survey
for binaries
among some of the most massive, least massive, and oldest
stars in our
part of the Galaxy. FGS allows us to spatially resolve
binary systems
that are too faint to observe using ground-based, speckle
or optical
long baseline interferometry, and too close to resolve
with AO. We
propose a SNAP-style program of single orbit FGS TRANS
mode observations
of very massive stars in the cluster NGC 3603, luminous
blue variables,
nearby low mass main sequence stars, cool subdwarf stars,
and white
dwarfs. These observations will help us to (1) identify
systems suitable
for follow up studies for mass determination, (2) study
the role of
binaries in stellar birth and in advanced evolutionary
states, (3)
explore the fundamental properties of stars near the main
sequence-brown
dwarf boundary, (4) understand the role of binaries for
X-ray bright
systems, (5) find binaries among ancient and nearby
subdwarf stars, and
(6) help calibrate the white dwarf mass - radius relation.
FGS 11943
Binaries at the Extremes of the H-R Diagram
We propose to use HST/Fine Guidance Sensor 1r to survey
for binaries
among some of the most massive, least massive, and oldest
stars in our
part of the Galaxy. FGS allows us to spatially resolve
binary systems
that are too faint for ground-based, speckle or optical
long baseline
interferometry, and too close to resolve with AO. We
propose a
SNAP-style program of single orbit FGS TRANS mode
observations of very
massive stars in the cluster NGC 3603, luminous blue
variables, nearby
low mass main sequence stars, cool subdwarf stars, and
white dwarfs.
These observations will help us to (1) identify systems
suitable for
follow up studies for mass determination, (2) study the
role of binaries
in stellar birth and in advanced evolutionary states, (3)
explore the
fundamental properties of stars near the main
sequence-brown dwarf
boundary, (4) understand the role of binaries for X-ray
bright systems,
(5) find binaries among ancient and nearby subdwarf stars,
and (6) help
calibrate the white dwarf mass - radius relation.
WFPC2 11793
WFPC2 Cycle 16 Internal Monitor
This calibration proposal is the Cycle 15 routine internal
monitor for
WFPC2, to be run weekly to monitor the health of the
cameras. A variety
of internal exposures are obtained in order to provide a
monitor of the
integrity of the CCD camera electronics in both bays (both
gain 7 and
gain 15 -- to test stability of gains and bias levels), a
test for
quantum efficiency in the CCDs, and a monitor for possible
buildup of
contaminants on the CCD windows. These also provide raw
data for
generating annual super-bias reference files for the
calibration
pipeline.
WFPC2 11302
WFPC2 CYCLE 16 Standard Darks - Part III
This dark calibration program obtains dark frames every
week in order to
provide data for the ongoing calibration of the CCD dark
current rate,
and to monitor and characterize the evolution of hot
pixels. Over an
extended period these data will also provide a monitor of
radiation
damage to the CCDs.
ACS/SBC 11236
Did Rare, Large Escape-Fraction Galaxies Reionize the
Universe?
Lyman continuum photons produced in massive starbursts may
have played a
dominant role in the reionization of the Universe.
Starbursts are
important contributors to the ionizing metagalactic
background at lower
redshifts as well. However, their contribution to the
background depends
upon the fraction of ionizing radiation that escapes from
the intrinsic
opacity of galaxies below the Lyman limit. Current surveys
suggest that
the escape fraction is close to zero in most galaxies,
even among young
starbursts, but is large in 15-25% of them. Non-uniform
escape fractions
are expected as a result of violent events creating clear
paths in small
parts of galaxies. The number of galaxies observed with
high escape
fraction will result from the combination of the intrinsic
number with
clear lines of sight and their orientation with respect to
the observer.
We propose to measure the fraction of escaping Lyman
continuum radiation
in a large sample (47) of z~0.7 starbursts in the COSMOS
field. These
compact UV-luminous galaxies are good analogs to high
redshift LBGs.
Using the SBC/PR130L we can quickly (1-4 orbits) detect
relative escape
fractions (f_LC/f_1500) of 25% or more. This will be the
first
measurement of the escape fraction in sources between z=1
and the local
universe. We expect ~10 detections. Stacking will set
limits of <4% on
the relative escape fraction in the rest. We will
correlate the LC
detections with the properties of the galaxies. By
targeting z~0.7 in
COSMOS, we will have tremendous ancillary information on
those sources.
A non-detection in all sources would be significant (99%
confidence).
This would imply that QSOs provide the overwhelming
majority of ionizing
radiation at z<1, requiring substantial evolution in
the processes
within Lyman break galaxies which allow large escape
fractions at high
redshift.
ACS/SBC/WFPC2 11230
HST FUV Observations of Brightest Cluster Galaxies: The
Role of Star
Formation in Cooling Flows and BCG Evolution
The intracluster medium (ICM) now appears to be a very
dynamic place
where heating and cooling processes vie for dominance and
an uneasy
equilibrium is maintained. Since these same processes may
operate during
the process of galaxy formation, the centers of clusters
of galaxies
provide low redshift laboratories for studying the
critical processes
involved in galaxy formation and black hole growth. At the
present time,
the main questions are (1) How much gas is cooling out of
the ICM? (2)
How much star formation is ongoing? (3) What is the impact
of the gas
and star formation on the central BCG? In order to measure
the current
star formation in BCGs we have undertaken a program of
Spitzer IRAC and
MIPS observations. We are in process of obtaining
observations of a
sample of Brightest Cluster Galaxies in 70 clusters
selected from the
ROSAT all sky survey. In about 25% of the sources observed
so far, we
detect a mid-IR excess which we attribute to dust heated
by star
formation. We propose to obtain ACS/SBC observations of
the Lyman Alpha
emission line and the adjacent FUV continuum in 7 BCGs
which are in
cooling core clusters of galaxies and have a large mid-IR
excess. We
also propose WFPC2 F606W observations of the two clusters
without high
resolution imaging to allow us to image the dust on the
same scale as
the Far UV continuum. The FUV will allow us to confirm the
presence of
ongoing star formation in these BCGs and will allow us to
rule out an
AGN as the dominant contributor to the mid-IR. The
morphology and
spatial extent of the young stars and the heated dust and
CO will
constrain the spatial scale over which star formation
occurs and thus
where the cooling gas is deposited. The combination of our
FUV and IR
observations will allow us to estimate the star formation
rates which
must balance the rate at which cold gas is deposited in
the BCG. Our
proposed FUV observations will produce unique information
about the
cooling gas, the true mass accretion rates, and the star
formation rates
in BCGs and its effect on the galaxy.
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.
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.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal performance that will be
investigated.)
HSTARS:
11641 - NCC (NICMOS CRYO-COOLER) safed after restart @
017/0006z
11642 - GSAcq (2,3,2) failed to RGA Hold due to Search
Radius Limit
Exceeded on FGS-3 @017/17:57z
Observation affected: Astrometry Proposal 11944
COMPLETED OPS REQUEST:
18370-2 - Adjust NCS CPL Setpoint (20 1º steps) up to
15.0ºC
18382-4 - NCS Restart and Cooldown
18383-1 - 8051 History Buffer Snapshot
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
30
29
FGS
REacq
40
40
OBAD with Maneuver
126
125
SIGNIFICANT EVENTS:
FLASH Report NCC Compressor Restart:
At 016/14:47:32 UTC, the NCC compressor was successfully
restarted
At approximately 017/00:06:31, the NCC safed due to a
turboalternator
speed limit violation.