HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4570
PERIOD
COVERED: UT March 18, 2008 (DOY 078)
OBSERVATIONS
SCHEDULED
FGS
11295
Trigonometric
Calibration of the Distance Scale for Classical Novae
The
distance scale for classical novae is important for understanding
the
stellar physics of their thermonuclear runaways, their contribution
to
Galactic nucleosynthesis, and their use as extragalactic standard
candles.
Although it is known that there is a relationship between their
absolute
magnitudes at maximum light and their subsequent rates of
decline--the
well-known maximum-magnitude rate-of-decline {MMRD}
relation--it
is difficult to set the zero-point for the MMRD because of
the
very uncertain distances of Galactic novae. We propose to measure
precise
trigonometric parallaxes for the quiescent remnants of the four
nearest
classical novae. We will use the Fine Guidance Sensors, which
are
proven to be capable of measuring parallaxes with errors of ~0.2
mas,
well below what is possible from the ground.
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
11195
Morphologies
of the Most Extreme High-Redshift Mid-IR-luminous Galaxies
II:
The `Bump' Sources
The
formative phase of some of the most massive galaxies may be
extremely
luminous, characterized by intense star- and AGN-formation.
Till
now, few such galaxies have been unambiguously identified at high
redshift,
and thus far we have been restricted to studying the
low-redshift
ultraluminous infrared galaxies as possible analogs. We
have
recently discovered a sample of objects which may indeed represent
this
early phase in galaxy formation, and are undertaking an extensive
multiwavelength
study of this population. These objects are optically
extremely
faint {R>26} but nevertheless bright at mid-infrared
wavelengths
{F[24um] > 0.5 mJy}. Mid-infrared spectroscopy with
Spitzer/IRS
reveals that they have redshifts z~2, implying luminosities
~1E13
Lsun. Their mid-IR SEDs fall into two broad, perhaps overlapping,
categories.
Sources with brighter F[24um] exhibit power-law SEDs and SiO
absorption
features in their mid-IR spectra characteristic of AGN,
whereas
those with fainter F[24um] show a "bump" characteristic of the
redshifted
1.6um peak from a stellar population, and PAH emission
characteristic
of starformation. We have begun obtaining HST images of
the
brighter sources in Cycle 15 to obtain identifications and determine
kpc-scale
morphologies for these galaxies. Here, we aim to target the
second
class {the "bump" sources} with the goal of determining if these
constitute
morphologically different objects, or simply a "low-AGN"
state
of the brighter class. The proposed observations will help us
determine
whether these objects are merging systems, massive obscured
starbursts
{with obscuration on kpc scales!} or very reddened {locally
obscured}
AGN hosted by intrinsically low-luminosity galaxies.
NIC3
11333
NICMOS
non-linearity tests
This
program incorporates a number of tests to analyze the count rate
dependent
non-linearity seen in NICMOS spectro-photometric observations.
We
will observe a field with stars of a range in luminosity in NGC3603
with
NICMOS in NIC1: F090M, F110W, F140W, F160W NIC2: F110W, F160W,
F187W,
F205W, and F222M NIC3: F110W, F150W, F160W, F175W, and F222M. We
will
repeat the observations with flatfield lamp on, creating
artificially
high count-rates, allowing tests of NICMOS linearity as
function
of count rate. We first take exposures with the lamp off, then
exposures
with the lamp on, and repeat at the end with lamp off.
Finally,
we continue with taking darks during occultation.
We
will furthermore observe spectro-photometric standard P041C using the
G096,
G141, and G206 grisms in NIC3, and repeat the lamp off/on/off test
to
artificially create a high background.
WFPC2
11207
Star
Formation in the Perseus Cluster Cooling Flow
We
propose to obtain high resolution, UV/optical imaging of the
"accretion
populations" in the massive cooling flow of the Perseus
cluster
of galaxies. New GALEX observations show that the dominant
galaxy
in this nearby cluster, NGC 1275, has an extended network of
UV-bright
populations apparently formed recently from the intracluster
gas.
Cluster cooling flows are the most prominent of the environments
where
we can readily observe the cycle of gas accretion, star formation,
and
feedback from active nuclei that is thought to play a central role
in
the formation and evolution of galaxies. Because they can be readily
age-dated,
the accretion populations help to trace the sequence of
exchange
of material between galaxies and the intracluster medium. The
ACS/SBC
and WFPC2/PC cameras offer the highest spatial resolution and
best
panchromatic performance available to map the spatial and age
distribution
of the accretion populations and their relationship to
radio-emitting
plasma and the hot intracluster gas.
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
11343
Identifying
the host galaxies for optically dark gamma-ray bursts
We
propose to use the high spatial resolution capabilities of Chandra to
obtain
precise positions for a sample of Gamma-ray bursts (GRBs) with no
optical
afterglows, where the optical light is supresssed relative to
the
X-ray flux. These bursts are likely to be highly obscured and may
have
different environments from the optically bright GRBs. Our Chandra
observations
will (unlike Swift-XRT positions) allow for the unique
identification
of a host galaxy. To locate these host galaxies we will
follow
up our Chandra positions with deep optical and IR observations
with
HST. The ultimate aim is to understand any differences between the
host
galaxies of optically dark and bright GRBs, and how these affect
the
use of GRBs as tracers of starformation and galaxy evolution at high
redshift.
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
10
10
FGS
REacq
04
04
OBAD
with Maneuver
28
28
SIGNIFICANT
EVENTS: (None)