HUBBLE
SPACE TELESCOPE - Continuing to collect World Class Science
DAILY
REPORT # 4582
PERIOD
COVERED: UT April 03, 2008 (DOY 094)
OBSERVATIONS
SCHEDULED
NIC1/NIC2/NIC3
8795
NICMOS Post-SAA calibration - CR Persistence Part 6
A new
proceedure proposed to alleviate the CR-persistence problem of
NICMOS.
Dark frames will be obtained immediately upon exiting the SAA
contour
23, and everytime 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
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
11120
A
Paschen-Alpha Study of Massive Stars and the ISM in the Galactic
Center
The
Galactic center (GC) is a unique site for a detailed study of a
multitude
of complex astrophysical phenomena, which may be common to
nuclear
regions of many galaxies. Observable at resolutions
unapproachable
in other galaxies, the GC provides an unparalleled
opportunity
to improve our understanding of the interrelationships of
massive
stars, young stellar clusters, warm and hot ionized gases,
molecular
clouds, large scale magnetic fields, and black holes. We
propose
the first large-scale hydrogen Paschen alpha line survey of the
GC
using NICMOS on the Hubble Space Telescope. This survey will lead to
a
high resolution and high sensitivity map of the Paschen alpha line
emission
in addition to a map of foreground extinction, made by
comparing
Paschen alpha to radio emission. This survey of the inner 75
pc
of the Galaxy will provide an unprecedented and complete search for
sites
of massive star formation. In particular, we will be able to (1)
uncover
the distribution of young massive stars in this region, (2)
locate
the surfaces of adjacent molecular clouds, (3) determine
important
physical parameters of the ionized gas, (4) identify compact
and
ultra-compact HII regions throughout the GC. When combined with
existing
Chandra and Spitzer surveys as well as a wealth of other
multi-wavelength
observations, the results will allow us to address such
questions
as where and how massive stars form, how stellar clusters are
disrupted,
how massive stars shape and heat the surrounding medium, and
how
various phases of this medium are interspersed.
WFPC2
11029
WFPC2
CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly
Monitor
Intflat
observations will be taken to provide a linearity check: the
linearity
test consists of a series of intflats in F555W, in each gain
and
each shutter. A combination of intflats, visflats, and earthflats
will
be used to check the repeatability of filter wheel motions.
{Intflat
sequences tied to decons, visits 1-18 in prop 10363, have been
moved
to the cycle 15 decon proposal xxxx for easier scheduling.} Note:
long-exposure
WFPC2 intflats must be scheduled during ACS anneals to
prevent
stray light from the WFPC2 lamps from contaminating long ACS
external
exposures.
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
11121
Proper
Motion of the Remarkable Irradiated Jet HH399 in the Trifid
Nebula
The
Trifid nebula has recently been of much interest because of its
identification
with a large number of massive protostars, as well as
young
stellar objects. HH 399 is one of the most spectacular Herbig-Haro
flows
recognized to be irradiated by the UV flux of the massive O7.5
star
in the Trifid nebula. The irradiated jet, which is propagating in a
fully
ionized medium, contains numerous knots along the jet and also
shows
evidence for a number of isolated knots running immediately
outside
the jet. Two different HST observations of the nebula, with
different
scientific goals, were carried out in 1997 and 2002, having
sensitivities
that differed by a factor of 10. We performed preliminary
proper
motion measurements of the jet based on these observations and
discovered
a continuous velocity structure of the bright knots of about
230
km/sec. Here we propose four WFPC2 orbits to reobserve HH 399 in
order
to carry out accurate proper motion measurements over the full
extent
of the jet, based on observations spanning more than 10 years and
having
equally deep sensitivity. The proposed observations are not
simply
a repeat of previous measurements, as this will be the first
highly
accurate proper motion measurement of an irradiated jet based on
two
identical epochs of WFPC2 observations. The observations will
improve
the accuracy of proper motion measurements for HH 399 by more
than
a factor of five and will address important questions beyond our
preliminary
result. Currently measured velocity differences between the
jet
features are barely significant. The factor of 5 increase in
accuracy
will establish the evidence for deceleration along the jet and
the
lateral motion of the jet. In addition, these measurements will
address
the kinematics of individual entrained and isolated blobs of the
jet
as it propagates into an HII region associated with the nebula. This
is
the last opportunity to perform this experiment before WFPC2 is
removed
from HST.
WFPC2
11128
Time
Scales Of Bulge Formation In Nearby Galaxies
Traditionally,
bulges are thought to fit well into galaxy formation
models
of hierarchical merging. However, it is now becoming well
established
that many bulges formed through internal, secular evolution
of
the disk rather than through mergers. We call these objects
pseudobulges.
Much is still unknown about pseudobulges, the most
pressing
questions being: How, exactly, do they build up their mass? How
long
does it take? And, how many exist? We are after an answer to these
questions.
If pseudobulges form and evolve over longer periods than the
time
between mergers, then a significant population of pseudobulges is
hard
to explain within current galaxy formation theories. A pseudobulge
indicates
that a galaxy has most likely not undergone a major merger
since
the formation of the disk. The ages of pseudobulges give us an
estimate
for the time scale of this quiescent evolution. We propose to
use
24 orbits of HST time to complete UBVIH imaging on a sample of 33
nearby
galaxies that we have observed with Spitzer in the mid-IR. These
data
will be used to measure spatially resolved stellar population
parameters
{mean stellar age, metallicity, and star formation history};
comparing
ages to star formation rates allows us to accurately constrain
the
time scale of pseudobulge formation. Our sample of bulges includes
both
pseudo- and classical bulges, and evenly samples barred and
unbarred
galaxies. Most of our sample is imaged, 13 have complete UBVIH
coverage;
we merely ask to complete missing observations so that we may
construct
a uniform sample for studying bulge formation. We also wish to
compare
the stellar population parameters to a variety of bulge and
global
galaxy properties including star formation rates, dynamics,
internal
bulge morphology, structure from bulge-disk decompositions, and
gas
content. Much of this data set is already or is being assembled.
This
will allow us to derive methods of pseudobulge identification that
can
be used to accurately count pseudobulges in large surveys. Aside
from
our own science goals, we will present this broad set of data to
the
community. Thus, we waive proprietary periods for all observations.
WFPC2
11229
SEEDS:
The Search for Evolution of Emission from Dust in Supernovae with
HST
and Spitzer
The
role that massive stars play in the dust content of the Universe is
extremely
uncertain. It has long been hypothesized that dust can
condense
within the ejecta of supernovae {SNe}, however there is a
frustrating
discrepancy between the amounts of dust found in the early
Universe,
or predicted by nucleation theory, and inferred from SN
observations.
Our SEEDS collaboration has been carefully revisiting the
observational
case for dust formation by core- collapse SNe, in order to
quantify
their role as dust contributors in the early Universe. As dust
condenses
in expanding SN ejecta, it will increase in optical depth,
producing
three simultaneously observable phenomena: {1} increasing
optical
extinction; {2} infrared {IR} excesses; and {3} asymmetric
blue-shifted
emission lines. Our SEEDS collaboration recently reported
all
three phenomena occurring in SN2003gd, demonstrating the success of
our
observing strategy, and permitting us to derive a dust mass of up to
0.02
solar masses created in the SN. To advance our understanding of the
origin
and evolution of the interstellar dust in galaxies, we propose to
use
HST's WFPC2 and NICMOS instruments plus Spitzer's photometric
instruments
to monitor ten recent core-collapse SNe for dust formation
and,
as a bonus, detect light echoes that can affect the dust mass
estimates.
These space-borne observations will be supplemented by
ground-based
spectroscopic monitoring of their optical emission line
profiles.
These observations would continue our 2-year HST and Spitzer
monitoring
of this phenomena in order to address two key questions: Do
all
SNe produce dust? and How much dust do they produce? As all the SN
are
within 15 Mpc, each SN stands an excellent chance of detection with
HST
and Spitzer and of resolving potential light echoes.
WFPC2
11326
Polarizers
Closeout (Internal Observations)
Verify
stability of polarization calibration.
FLIGHT
OPERATIONS SUMMARY:
Significant
Spacecraft Anomalies: (The following are preliminary reports
of
potential non-nominal performance that will be investigated.)
HSTARS:
11239
- GSacq(2,1,2) failed, Search Radius Limit exceeded on FGS 2
Upon acquisition of signal at 12:55:55, vehicle was in gyro
control with
FGS2 search radius limit and stop flags set. GSACQ(2,1,2) at
12:11:54
failed to RGA control. One 486 status buffer "A05"
message (FGS Coarse
Track failed- Search Radius Limit exceeded) was received. OBAD at
11:59:49 prior to GSACQ had RSS error correction of 15.40 arc
seconds,
OBAD map at 12:57:29 after GSACQ had RSS error of 2340.74
arcseconds.
OBAD at 11:51:59 prior to GSACQ had RSS error correction of
5217.70
arc seconds.
11240
- GSacq(2,1,2) failed, Search Radius Limit exceeded on FGS 2
Upon acquisition of signal at 14:02:15, vehicle was in gyro
control with
FGS2 search radius limit and stop flags set. GSACQ(2,1,2) at
13:47:16
failed to RGA control. One 486 status buffer "A05"
message (FGS Coarse
Track failed- Search Radius Limit exceeded) was received. OBAD at
13:35:37 prior to GSACQ had RSS error correction of 11.12 arc
seconds,
OBAD map at 14:32:55 after GSACQ had RSS error of 1678.45
arcseconds.
*
11242
- GSAcq(2,1,2) failed
OTA SE review of PTAS processing revealed that GSAcq(2,1,2) at
086/23:42:09 failed to RGA Hold with a stop flag on FGS2.
COMPLETED
OPS REQUEST: (None)
COMPLETED
OPS NOTES: (None)
SCHEDULED
SUCCESSFUL
FGS
GSacq
10
08
FGS
REacq
03
03
OBAD
with Maneuver
28
28
SIGNIFICANT
EVENTS: (None)