HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4607
PERIOD
COVERED: 5am May 08 - 5am May 09, 2008 (DOY 129/0900z - 130/0900z)
OBSERVATIONS
SCHEDULED
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
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/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}.
S/C
11163
Accreting
Pulsating White Dwarfs in Cataclysmic Variables
Recent
ground-based observations have increased the number of known
pulsating
white dwarfs in close binaries with active mass transfer
{cataclysmic
variables} from 5 to 11 systems. Our past Cycles 8 and 11
STIS
observations of the first 2 known, followed by our Cycle 13 SBC
observations
of the next 3 discovered, revealed the clear presence of
the
white dwarf and increased amplitude of the pulsations in the UV
compared
to the optical. The temperatures derived from the UV spectra
show
4 systems are much hotter than non-interacting pulsating white
dwarfs.
A larger sample is needed to sort out the nature of the
instability
strip in accreting pulsators i.e. whether effects of
composition
and rotation due to accretion result in a well- defined
instability
strip as a function of Teff.
WFPC2
11216
HST
/ Chandra Monitoring of a Dramatic Flare in the M87 Jet
As
the nearest galaxy with an optical jet, M87 affords an unparalleled
opportunity
to study extragalactic jet phenomena at the highest
resolution.
During 2002, HST and Chandra monitoring of the M87 jet
detected
a dramatic flare in knot HST-1 located ~1" from the nucleus.
Its
optical brightness eventually increased seventy-fold and peaked in
2005;
the X-rays show a similarly dramatic outburst. In both bands HST-1
is
still extremely bright and greatly outshines the galaxy nucleus. To
our
knowledge this is the first incidence of an optical or X-ray
outburst
from a jet region which is spatially distinct from the core
source
-- this presents an unprecedented opportunity to study the
processes
responsible for non-thermal variability and the X-ray
emission.
We propose five epochs of HST/WFPC2 flux monitoring during
Cycle
16, as well as seven epochs of Chandra/ACIS observation {5ksec
each,
six Chandra epochs contemporary with HST}. At two of the HST/WFPC2
epochs
we also gather spectral information, and at one epoch we will map
the
magnetic field structure. The results of this investigation are of
key
importance not only for understanding the nature of the X-ray
emission
of the M87 jet, but also for understanding flares in blazar
jets,
which are highly variable, but where we have never before been
able
to resolve the flaring region in the optical or X-rays. These new
observations
will allow us to track the decay phase of the giant flare,
and
study smaller secondary flares such as seen late in 2006. Ultimately
we
will test synchrotron emission models for the X-ray outburst,
constrain
particle acceleration and loss timescales, and study the jet
dynamics
associated with this flaring component.
WFPC2
11551
When
degenerate stars collide: Understanding A New Explosion Phenomena
Explosive
events seen at extragalactic distances mark the end-state of
violent
and catastrophic physical processes. Most supernovae and
gamma-ray
bursts (GRBs), in particular, are thought to herald the death
of
massive stars and the birth of solar-mass black holes. A minority
fraction
of GRBs, however, have been circumstantially associated with
the
merger of degenerate systems (such as black holes and neutron
stars).
These short-duration bursts are rare and difficult to localize,
with
only about 2 dozen studied to any degree of detail to date. We
believe
that we have finally discovered, in the last few days, one of
the
tell-tale signatures of degenerate merger products --- a
"mini-supernova"
from the non-relativistic ejecta left over after
merger.
If true, this long-theorized phenomenon would be an entirely new
sort
of explosion in the universe. In several rapidly executed visits,
HST,
coupled with a recently approved Chandra DD proposal to search for
underlying
afterglow, could make a substantial contribution to our
understanding
of this phenomena by honing the physical parameters of the
event
and helping to rule out alternatives. If we are correct in our
hypothesis,
we have found the first clear cut observational signature in
the
electromagnetic spectrum of what are expected to the be the dominant
sources
of gravitational waves for advanced LIGO.
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
05
05
FGS
REacq
08
08
OBAD
with Maneuver 26
26
SIGNIFICANT
EVENTS: (None)