HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4523
PERIOD
COVERED: UT January 009, 2008 (DOY 009)
OBSERVATIONS
SCHEDULED
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
11219
Active
Galactic Nuclei in nearby galaxies: a new view of the origin of
the
radio-loud radio-quiet dichotomy?
Using
archival HST and Chandra observations of 34 nearby early-type
galaxies
{drawn from a complete radio selected sample} we have found
evidence
that the radio-loud/radio-quiet dichotomy is directly connected
to the
structure of the inner regions of their host galaxies in the
following
sense: [1] Radio-loud AGN are associated with galaxies with
shallow
cores in their light profiles [2] Radio-quiet AGN are only
hosted
by galaxies with steep cusps. Since the brightness profile is
determined
by the galaxy's evolution, through its merger history, our
results
suggest that the same process sets the AGN flavour. This
provides
us with a novel tool to explore the co-evolution of galaxies
and
supermassive black holes, and it opens a new path to understand the
origin
of the radio-loud/radio-quiet AGN dichotomy. Currently our
analysis
is statistically incomplete as the brightness profile is not
available
for 82 of the 116 targets. Most galaxies were not observed
with
HST, while in some cases the study is obstructed by the presence of
dust
features. We here propose to perform an infrared NICMOS snapshot
survey
of these 82 galaxies. This will enable us to i} test the reality
of
the dichotomic behaviour in a substantially larger sample; ii} extend
the
comparison between radio-loud and radio-quiet AGN to a larger range
of
luminosities.
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
11104
The
nature of radio transients
We
have conducted the first ever blind, wide-field survey for radio
transients (Levinson et al. 2002; Gal-Yam et al. 2006). We have
discovered
four radio transients and explored their nature using radio
and
optical follow-up observations. One is a known pulsar, one is a
z~0.1
AGN, and one is most probably an optically obscured radio
supernova
(SN) in the nearby galaxy NGC 4216 (the first such event to be
discovered
by a wide field radio survey). The last source appears not to
be
associated with a bright host galaxy (to a limit of R < 24.5 mag). We
request
4 orbits of WFPC2 F606W imaging to check whether we can
establish
an association between this radio transient and any of three
nearby
faint resolved galaxies we have detected from the ground. If the
source
is associated with any of these galaxies it would represent a new
type
of extra-galactic radio bursts, more luminous than, e.g., radio
afterglows
of gamma-ray bursts. Alternatively, ruling out an association
with
these galaxies would disfavor an extra-galactic nature of this
object,
and suggest instead that this is a radio outburst of a faint
Galactic
compact object, probably a new type of radio-flaring neutron
star.
If this is the case, the high luminosity (9 mJy) and relatively
high
galactic latitude (33 degrees) of this source may indicate it is
relatively
nearby. This single source represents a large population
(comparable
in sky density to AGN, pulsars, and radio SNe) and thus
merits
intensive study. A modest investment of HST time, leveraged by
massive
ground-based radio and optical efforts, will allow us to
identify
a new class of radio sources, and complete a census of the
variable
radio sky down to ~6 mJy, leaving no unidentified objects. This
result
can be directly scaled to predict the number and type of
transient
sources expected to be detected by future surveys with the
next
generation radio arrays, such as ATA and SKA. Since our science
critically
requires HST's spatial resolution (rather than sensitivity)
it
is perfectly suited to be carried out with WFPC2.
WFPC2
11217
The
Light Echoes around V838 Monocerotis
V838
Monocerotis, which burst upon the astronomical scene in early 2002,
is
a completely unanticipated new object. It underwent a large-amplitude
and
very luminous outburst, during which its spectrum remained that of
an
extremely cool supergiant. A rapidly evolving set of light echoes
around
V838 Mon was discovered soon after the outburst, and quickly
became
the most spectacular display of the phenomenon ever seen. These
light
echoes provide the means to accomplish three unique types of
measurements
based on continued HST imaging during the event: {1} Study
effects
of MHD turbulence at high resolution and in 3 dimensions; {2}
Construct
the first unambiguous and fully 3-D map of a circumstellar
dust
envelope in the Milky Way; {3} Study dust physics in a unique
setting
where the spectrum and light curve of the illumination, and the
scattering
angle, are unambiguously known. We have also used our HST
data
to determine the distance to V838 Mon through direct geometric
techniques.
Because of the extreme rarity of light echoes, this is
almost
certainly the only opportunity to achieve such results during the
lifetime
of HST. We propose two visits during Cycle 16, in order to
continue
the mapping of the circumstellar dust and to accomplish the
other
goals listed above.
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:
18169-0
Add G1 UKF Input Configuration
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
05
05
FGS
REacq
08
08
OBAD
with Maneuver
26
26
SIGNIFICANT
EVENTS:
Ops
Request 18169-0 execution succeeded at 2008/009 14:11:43. The Kalman
filter
was disabled, gyro 1 input was enabled, and the UKF was
re-initialized.
UKF performance was nominal following re-initialization;
peak
attitude estimate errors of about 3 degrees RSS occurred after
initialization
and steady-state performance exhibited less than 1 degree
error.
This UKF re-configuration establishes the OGS OOT input
configuration
for pre-test performance monitoring.