HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4609
PERIOD
COVERED: 5am May 12 - 5am May 13, 2008 (DOY 133/0900z-134/0900z)
OBSERVATIONS
SCHEDULED
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.
WFPC2
11024
WFPC2
CYCLE 15 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.
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 DARKs. 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.
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}.
WEPC2
11196
An
Ultraviolet Survey of Luminous Infrared Galaxies in the Local
Universe
At
luminosities above 10^11.4 L_sun, the space density of far-infrared
selected
galaxies exceeds that of optically selected galaxies. These
Luminous
Infrared Galaxies {LIRGs} are primarily interacting or merging
disk
galaxies undergoing starbursts and creating/fueling central AGN. We
propose
far {ACS/SBC/F140LP} and near {WFPC2/PC/F218W} UV imaging of a
sample
of 27 galaxies drawn from the complete IRAS Revised Bright Galaxy
Sample
{RBGS} LIRGs sample and known, from our Cycle 14 B and I-band ACS
imaging
observations, to have significant numbers of bright {23 < B < 21
mag}
star clusters in the central 30 arcsec. The HST UV data will be
combined
with previously obtained HST, Spitzer, and GALEX images to {i}
calculate
the ages of the clusters as function of merger stage, {ii}
measure
the amount of UV light in massive star clusters relative to
diffuse
regions of star formation, {iii} assess the feasibility of using
the
UV slope to predict the far-IR luminosity {and thus the star
formation
rate} both among and within IR-luminous galaxies, and {iv}
provide
a much needed catalog of rest- frame UV morphologies for
comparison
with rest-frame UV images of high-z LIRGs and Lyman Break
Galaxies.
These observations will achieve the resolution required to
perform
both detailed photometry of compact structures and spatial
correlations
between UV and redder wavelengths for a physical
interpretation
our IRX-Beta results. The HST UV data, combined with the
HST
ACS, Spitzer, Chandra, and GALEX observations of this sample, will
result
in the most comprehensive study of luminous starburst galaxies to
date.
WFPC2
10888
Complexity
in the Smallest Galaxies: Star Formation History of the
Sculptor
Dwarf Spheroidal
The
Sculptor dwarf spheroidal galaxy {Scl dSph} is one of the most
luminous
of the Milky Way dSph satellites, suffers virtually no
foreground
confusion or reddening because of its high galactic latitude,
and
is nearby at 80 kpc from the Sun. It is of great interest to
astronomy
to understand the detailed histories of dSph galaxies because
they
may be survivors of the hierarchical merging process that created
giant
galaxies like our own. Despite this, the age distribution of stars
in
Scl dSph remains remarkably poorly constrained because of a dearth of
high-quality
color-magnitude diagrams {CMDs} of its central regions. Scl
dSph
is known to be complex on the basis of shallower photometry, radial
velocity
studies, and investigations of the metallicity; however, the
age
range of significant star-formation and the proportion of stars
older
and younger than 10 Gyr is still completely unknown. The age of
the
centrally concentrated, metal-rich population has never been
measured.
We propose to obtain deep optical images of the core of Scl
dSph
with WFPC2 in order to measure the temporal evolution of its star-
formation
rate over its entire lifetime. The ONLY way to reliably
measure
the variation in star- formation rate on Gyr timescales at ages
of
10-13 Gyr is with photometry of a large number of stars at and below
the
oldest main-sequence turnoffs to magnitudes of {B,I} = {25.1, 24.5}.
Because
of the high stellar density and resulting image crowding, it is
impossible
to achieve the required level of photometric precision except
with
diffraction-limited imaging. These data will permit the first
reliable
measurement of the star-formation history of the main body of
Scl
dSph; limited inferences from WFPC2 data in an outer field have been
made,
but they were hindered not only by small number statistics but by
the
subsequent revelation of extremely strong population gradients in
Scl
dSph, such that the stars in the existing WFPC2 field are not
representative
of the galaxy as a whole. Our proposed program will shed
strong
new light on the formation processes of the smallest galaxies.
Only
by measuring the detailed early histories of galaxies like Scl dSph
can
we evaluate the impact of outside influences like ram-pressure
stripping,
tidal stirring, and photoionization feedback on the evolution
of
small galaxies.
WFPC2
11070
WFPC2
CYCLE 15 Standard Darks - part II
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.
WFPC2
11235
HST
NICMOS Survey of the Nuclear Regions of Luminous Infrared Galaxies
in
the Local Universe
At
luminosities above 10^11.4 L_sun, the space density of far-infrared
selected
galaxies exceeds that of optically selected galaxies. These
`luminous
infrared galaxies' {LIRGs} are primarily interacting or
merging
disk galaxies undergoing enhanced star formation and Active
Galactic
Nuclei {AGN} activity, possibly triggered as the objects
transform
into massive S0 and elliptical merger remnants. We propose
NICMOS
NIC2 imaging of the nuclear regions of a complete sample of 88
L_IR
> 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised
Bright
Galaxy Sample {RBGS: i.e., 60 micron flux density > 5.24 Jy}.
This
sample is ideal not only in its completeness and sample size, but
also
in the proximity and brightness of the galaxies. The superb
sensitivity
and resolution of NICMOS NIC2 on HST enables a unique
opportunity
to study the detailed structure of the nuclear regions,
where
dust obscuration may mask star clusters, AGN and additional nuclei
from
optical view, with a resolution significantly higher than possible
with
Spitzer IRAC. This survey thus provides a crucial component to our
study
of the dynamics and evolution of IR galaxies presently underway
with
Wide-Field, HST ACS/WFC and Spitzer IRAC observations of these 88
galaxies.
Imaging will be done with the F160W filter {H-band} to examine
as
a function of both luminosity and merger stage {i} the luminosity and
distribution
of embedded star clusters, {ii} the presence of optically
obscured
AGN and nuclei, {iii} the correlation between the distribution
of
1.6 micron emission and the mid- IR emission as detected by Spitzer
IRAC,
{iv} the evidence of bars or bridges that may funnel fuel into the
nuclear
region, and {v} the ages of star clusters for which photometry
is
available via ACS/WFC observations. The NICMOS data, combined with
the
HST ACS, Spitzer, and GALEX observations of this sample, will result
in
the most comprehensive study of merging and interacting galaxies to
date.
WFPC2
11518
Mutual
eclipses of a Kuiper belt-satellite system
Ground-based
observations two weeks ago strongly suggest that the orbit
of
the small inner satellite of 2003 EL61, the 5th largest known dwarf
planet,
is possibly precisely edge-on and thus somewhere in the middle
of
a ~3 year long cycle of mutual eclipses, occultations, and transits.
We
anticipate that with another year of ground-based observation we may
have
sufficient data to accurately predict the times and durations of
these
events, but by then the events may well be over. If events are
indeed
occuring, measurement of the timing and depths of such events
provides
a wealth of precise geometric information for constraining
sizes,
shapes, orbits, and dynamics of the system.
We propose
to obtain 5 quick WFPC2 visits to 2003 EL61 over the ~19 day
orbital
period of the inner satellite to determine a precise orbit and
predict
mutual event times. We will instantly (within ~1 day of the end
of
the observations) make these predictions public to allow the maximum
number
of attempts to collect the data as possible.
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
07
07
FGS
REacq
07
07
OBAD
with Maneuver
28
28
SIGNIFICANT
EVENTS: (None)