HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT #4669
PERIOD
COVERED: 5am August 6 - 5am August 7, 2008 (DOY 219/0900z-220/0900z)
OBSERVATIONS
SCHEDULED
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.
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
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.
NIC2
11135
Extreme
Makeovers: Tracing the Transformation of Massive Galaxies at
z~2.5
To
obtain a full spectroscopic census of the universe at z~2.5 we have
conducted
a near-infrared spectroscopic survey for K-selected galaxies.
We
found that, in contrast to the local universe, massive high-redshift
galaxies
span a wide range of properties, varying from (dusty) star
burst
to "red and dead" galaxies. This may imply that massive galaxies
transform
from star-forming to quiescent galaxies in the targeted
redshift
range. To understand whether the 9 quiescent galaxies in our
sample
are the progenitors of local elliptical, we are observing them in
the
current cycle with NIC2. For cycle 16 we propose to complete our
sample
of massive z~2.5 galaxies and image the remaining 10 galaxies,
which
all have emission lines. Based on emission-line diagnostics, 6 of
these
galaxies are identified as star-forming objects and 4 harbor an
active
galactic nucleus. The goals are to 1) determine whether star
formation
in massive z~2.5 galaxies takes place in disks or is triggered
by
merger activity, 2) derive the contribution of AGNs to the rest-frame
optical
emission, and 3) test whether the morphologies are consistent
with
the idea that the star-forming galaxies, AGNs, and quiescent
galaxies
represent subsequent phases of an evolutionary sequence. The
combination
of both programs will provide the first morphological study
of
a spectroscopically confirmed massive galaxy sample at z~2.5.
NIC2
11197
Sweeping
Away the Dust: Reliable Dark Energy with an Infrared Hubble
Diagram
We
propose building a high-z Hubble Diagram using type Ia supernovae
observed
in the infrared rest-frame J-band. The infrared has a number of
exceptional
properties. The effect of dust extinction is minimal,
reducing
a major systematic that may be biasing dark energy
measurements.
Also, recent work indicates that type Ia supernovae are
true
standard candles in the infrared meaning that our Hubble diagram
will
be resistant to possible evolution in the Phillip's relation over
cosmic
time. High signal-to-noise measurements of 16 type Ia events at
z~0.4
will be compared with an independent optical Hubble diagram from
the
ESSENCE project to test for a shift in the derived dark energy
equation
of state due to a systematic bias. In Cycle 15 we obtained
NICMOS
photometry of 8 ESSENCE supernovae and are awaiting template
observations
to place them on the IR Hubble diagram. Here we request
another
8 supernovae be studied in the final season of the ESSENCE
search.
Because of the bright sky background, H-band photometry of z~0.4
supernovae
is not feasible from the ground. Only the superb image
quality
and dark infrared sky seen by HST makes this test possible. This
experiment
may also lead to a better, more reliable way of mapping the
expansion
history of the universe with the Joint Dark Energy Mission.
NIC2/WFPC2
11142
Revealing
the Physical Nature of Infrared Luminous Galaxies at 0.3<z<2.7
Using
HST and Spitzer
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
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 individual
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
11122
Expanding
PNe: Distances and Hydro Models
We
propose to obtain repeat narrowband images of a sample of eighteen
planetary
nebulae {PNe} which have HST/WFPC2 archival data spanning time
baselines
of a decade. All of these targets have previous high
signal-to-noise
WFPC2/PC observations and are sufficiently nearby to
have
readily detectable expansion signatures after a few years. Our main
scientific
objectives are {a} to determine precise distances to these
PNe
based on their angular expansions, {b} to test detailed and highly
successful
hydrodynamic models that predict nebular morphologies and
expansions
for subsamples of round/elliptical and axisymmetric PNe, and
{c}
to monitor the proper motions of nebular microstructures in an
effort
to learn more about their physical nature and formation
mechanisms.
The proposed observations will result in high-precision
distances
to a healthy subsample of PNe, and from this their expansion
ages,
luminosities, CSPN properties, and masses of their ionized cores.
With
good distances and our hydro models, we will be able to determine
fundamental
parameters {such as nebular and central star masses,
luminosity,
age}. The same images allow us to monitor the changing
overall
ionization state and to search for the surprisingly
non-homologous
growth patterns to bright elliptical PNe of the same sort
seen
by Balick & Hajian {2004} in NGC 6543. Non-uniform growth is a sure
sign
of active pressure imbalances within the nebula that require
careful
hydro models to understand.
WFPC2
11203
A
Search for Circumstellar Disks and Planetary-Mass Companions around
Brown
Dwarfs in Taurus
During
a 1-orbit program in Cycle 14, we used
WFPC2
to obtain the first direct image of a circumstellar disk around a
brown
dwarf. These data have provided fundamental new constraints on the
formation
process of brown dwarfs and the properties of their disks. To
search
for additional direct detections of disks around brown dwarfs and
to
search for planetary-mass companions to these objects, we propose a
WFPC2
survey of 32 brown dwarfs in the Taurus star-forming region.
WFPC2
11796
WFPC2
Cycle 16 Decontaminations and Associated Observations
This
proposal is for the WFPC2 decons. Also included are instrument
monitors
tied to decons: photometric stability check, focus monitor,
pre-
and post-decon internals (bias, intflats, kspots, & darks), UV
throughput
check, VISFLAT sweep, and internal UV flat check.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
(None)
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
12
12
FGS
REacq
03
03
OBAD
with Maneuver 30
30
SIGNIFICANT
EVENTS: (None)