Notice: Due to the conversion of some ACS WFC or HRC
observations into
WFPC2, or NICMOS observations after
the loss of ACS CCD science
capability in January, there may be an
occasional discrepancy between a
proposal's listed (and correct) instrument
usage and the abstract that
follows it.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4405
PERIOD COVERED: UT July 16, 2007 (DOY 197)
OBSERVATIONS SCHEDULED
ACS/WFC/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 OB star population, {2} constraint on
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.
FGS 11210
The Architecture of Exoplanetary
Systems
Are all planetary systems coplanar? Concordance cosmogony
makes that
prediction. It is, however, a prediction
of extrasolar planetary system
architecture as yet untested by direct
observation for main sequence
stars other than the Sun. To provide
such a test, we propose to carry
out FGS astrometric
studies on four stars hosting seven companions. Our
understanding of the planet formation process
will grow as we match not
only system architecture, but formed
planet mass and true distance from
the primary with host star
characteristics for a wide variety of host
stars and exoplanet
masses. We propose that a series of FGS astrometric
observations with demonstrated 1 millisecond
of arc per-observation
precision can establish the degree of coplanarity and component true
masses for four extrasolar
systems: HD 202206 {brown dwarf+planet}; HD
128311 {planet+planet}, HD
160691 = mu Arae {planet+planet}, and HD
222404AB = gamma Cephei {planet+star}. In each case the companion is
identified as such by assuming that the
minimum mass is the actual mass.
For the last target, a known stellar binary system, the
companion orbit
is stable only if coplanar with
the AB binary orbit.
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 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.
WFPC2 11022
WFPC2 Cycle 15 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.
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 Monte Carlo technique to
optimally schedule our observations.
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.
WFPC2 11289
SL2S: The Strong Lensing Legacy
Survey
Recent systematic surveys of strong galaxy-galaxy lenses
{CLASS, SLACS,
GOODS, etc.} are
producing spectacular results for galaxy masses roughly
below a transition mass M~10^13 Mo.
The observed lens properties and
their evolution up to z~0.2,
consistent with numerical simulations, can
be described by isothermal
elliptical potentials. In contrast, modeling
of giant arcs in X-ray luminous
clusters {halo masses M >~10^13 Mo}
favors NFW mass profiles, suggesting
that dark matter halos are not
significantly affected by baryon cooling.
Until recently, lensing
surveys were neither deep nor extended
enough to probe the intermediate
mass density regime, which is
fundamental for understanding the assembly
of structures. The CFHT Legacy
Survey now covers 125 square degrees, and
thus offers a large reservoir of
strong lenses probing a large range of
mass densities up to z~1. We have
extracted a list of 150 strong lenses
using the most recent CFHTLS data
release via automated procedures.
Following our first SNAPSHOT proposal in cycle 15, we
propose to
continue the Hubble follow-up targeting
a larger list of 130 lensing
candidates. These are intermediate mass
range candidates {between
galaxies and clusters} that are selected
in the redshift range of 0.2-1
with no a priori X-ray selection.
The HST resolution is necessary for
confirming the lensing
candidates, accurate modeling of the lenses, and
probing the total mass concentration in
galaxy groups up to z~1 with the
largest unbiased sample available to
date.
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)
SCHEDULED
SUCCESSFUL
FGS GSacq
07 07
FGS REacq
08
08
OBAD with Maneuver
30
30
COMPLETED OPS NOTES: (None)
SIGNIFICANT EVENTS: (None)
-Lynn
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission Operations
Manager
Lockheed Martin Mission Services (LMMS)
NASA GSFC PH#: 301-286-2876
"The Hubble Space Telescope is the
astronomical observatory and key to unlocking the most cosmic mysteries of the
past, present and future." - 7/26/6