HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4547
PERIOD COVERED: UT February 13, 2008 (DOY 044)
OBSERVATIONS SCHEDULED
ACS/SBC 10862
Comprehensive Auroral Imaging of
Jupiter and Saturn during the
International Heliophysical Year
A comprehensive set of observations of the auroral emissions from
Jupiter and Saturn is proposed for the International Heliophysical Year
in 2007, a unique period of
especially concentrated measurements of
space physics phenomena throughout
the solar system. We propose to
determine the physical relationship of
the various auroral processes at
Jupiter and Saturn with conditions
in the solar wind at each planet.
This can be accomplished with campaigns of observations,
with a sampling
interval not to exceed one day, covering
at least one solar rotation.
The solar wind plasma density approaching Jupiter will be
measured by
the New Horizons spacecraft, and a
separate campaign near opposition in
May 2007 will determine the effect of large-scale
variations in the
interplanetary magnetic field {IMF} on the
Jovian aurora by
extrapolation from near-Earth solar wind
measurements. A similar Saturn
campaign near opposition in Jan. 2007
will combine extrapolated solar
wind data with measurements from a
wide range of locations within the
Saturn magnetosphere by Cassini. In the course of making these
observations, it will be possible to fully
map the auroral footprints of
Io and the other satellites to determine both the local
magnetic field
geometry and the controlling factors in
the electromagnetic interaction
of each satellite with the corotating magnetic field and plasma density.
Also in the course of making these observations, the auroral emission
properties will be compared with the
properties of the near-IR
ionospheric emissions {from ground-based
observations} and non thermal
radio emissions, from ground-based
observations for Jupiter's decametric
radiation and Cassini plasma wave
measurements of the Saturn Kilometric
Radiation {SKR}.
ACS/SBC 11154
Optical-UV Spectrum of the Middle-aged Pulsar B1055-52
The middle-aged radio, X-ray and gamma-ray pulsar B1055-52
is one of the
few pulsars that allow a multiwavelength study of pulsar radiation. An
optical counterpart of the pulsar has
been detected with the HST FOC,
but it was observed in only one
filter (F342W, m=24.9). To understand
the nature of the pulsar radiation,
its spectrum must be measured in a
broad wavelength range. We propose
imaging observations of the pulsar's
counterpart with WFPC2 in the red part of
the spectrum and ACS/SBC in
the UV part to measure the
broadband spectral distribution, compare it
with the X-ray spectrum, and
investigate the thermal and magnetospheric
components of the pulsar's radiation.
ACS/SBC 11220
Mapping the FUV Evolution of Type IIn
Supernovae
We will use the PR110L prism on the SBC of ACS to map the
FUV evolution
of Type IIn
supernovae {SNe}. The main goal of this proposal is
to
measure the FUV continuum, Ly-a
emission line flux, and their evolution
to {1} quantify and interpret Type
IIn SN transient event detections at
high redshift
and {2} dramatically improve current high redshift
Type
IIn selection
criteria.
We show that the inherent properties of Type IIn
SNe facilitate high redshift detection. We will observe the rest-frame
FUV of a sample of eight 0.02 < z < 0.33 Type IIn SNe to directly
measure the survival of Ly-alpha
photons in low to intermediate redshift
Type IIn SNe
environments and extrapolate the results to high redshift.
We will calibrate relationships such as FUV luminosity vs.
emission line
flux and measure emission line
evolution vs. FUV light evolution. The
intent is to categorize and improve
the utility of Type IIn SNe.
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.
NIC3 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.
WFPC2 11083
The Structure, Formation and Evolution of Galactic Cores
and Nuclei
A surprising result has emerged from the ACS Virgo Cluster
Survey
{ACSVCS}, a program to obtain ACS/WFC gz
imaging for a large, unbiased
sample of 100 early-type galaxies in
the Virgo Cluster. On subarcsecond
scales {i.e., <0.1"-1"},
the HST brightness profiles vary systematically
from the brightest giants {which
have nearly constant surface brightness
cores} to the faintest dwarfs {which
have compact stellar nuclei}.
Remarkably, the fraction of galaxy mass contributed by the
nuclei in the
faint galaxies is identical to that
contributed by supermassive black
holes in the bright galaxies {0.2%}.
These findings strongly suggest
that a single mechanism is
responsible for both types of Central Massive
Object: most likely internally or externally modulated gas
inflows that
feed central black holes or lead to
the formation of "nuclear star
clusters". Understanding the
history of gas accretion, star formation
and chemical enrichment on subarcsecond scales has thus emerged as the
single most pressing question in the
study of nearby galactic nuclei,
either active or quiescent. We propose
an ambitious HST program {199
orbits} that constitutes the next,
obvious step forward:
high-resolution, ultraviolet {WFPC2/F255W} and
infrared {NIC1/F160W}
imaging for the complete ACSVCS sample.
By capitalizing on HST's unique
ability to provide high-resolution
images with a sharp and stable PSF at
UV and IR wavelengths, we will leverage the existing
optical HST data to
obtain the most complete picture
currently possible for the history of
star formation and chemical
enrichment on these small scales. Equally
important, this program will lead to a
significant improvement in the
measured structural parameters and
density distributions for the stellar
nuclei and the underlying galaxies,
and provide a sensitive measure of
"frosting" by young
stars in the galaxy cores. By virtue of its superb
image quality and stable PSF, NICMOS
is the sole instrument capable of
the IR observations proposed here.
In the case of the WFPC2
observations, high-resolution UV imaging
{< 0.1"} is a capability unique
to HST, yet one that could be lost
at any time.
WFPC2 11103
A Snapshot Survey of The Most
Massive Clusters of Galaxies
We propose the continuation of our highly successful SNAPshot survey of
a sample of 125 very X-ray
luminous clusters in the redshift range
0.3-0.7. As demonstrated by the
25 snapshots obtained so far in Cycle14
and Cycle15 these systems
frequently exhibit strong gravitational
lensing as well as spectacular examples
of violent galaxy interactions.
The proposed observations will provide important
constraints on the
cluster mass distributions, the
physical nature of galaxy-galaxy and
galaxy-gas interactions in cluster cores,
and a set of optically bright,
lensed galaxies for further 8-10m
spectroscopy. All of our primary
science goals require only the
detection and characterization of
high-surface-brightness features and are thus
achievable even at the
reduced sensitivity of WFPC2. Because
of their high redshift and thus
compact angular scale our target
clusters are less adversely affected by
the smaller field of view of WFPC2
than more nearby systems.
Acknowledging the broad community interest in this sample
we waive our
data rights for these observations.
Due to a clerical error at STScI our
approved Cycle15 SNAP program was barred
from execution for 3 months and
only 6 observations have been
performed to date - reinstating this SNAP
at Cycle16 priority is of
paramount importance to reach meaningful
statistics.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal
performance that will be investigated.)
HSTARS:
11189 - GSACQ(2,1,2) fine lock
backup on FGS 2
GSACQ(2,1,2) at 045/06:48:56 acquired in fine lock backup on
FGS 2 only,
with QF1STOPF and QSTOP flags set on FGS 1 at 06:53:44. No
other flags
were seen.
COMPLETED OPS REQUEST: (None)
COMPLETED OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS GSacq
09
09
FGS REacq
06
06
OBAD with Maneuver
30
30
SIGNIFICANT EVENTS: (None)
-Lynn
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP Mission
Operations Manager
CHAMP Flight Operations Team 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