Notice: Due to the conversion of some ACS WFC or HRC
observations into
WFPC2, or NICMOS observations after
the loss of ACS CCD science
capability in January, there may be an
occasional discrepancy between a
proposal's listed (and correct) instrument
usage and the abstract that
follows it.
HUBBLE SPACE TELESCOPE - Continuing to collect World Class
Science
DAILY REPORT # 4426
PERIOD COVERED: UT August 14, 2007 (DOY 226)
OBSERVATIONS SCHEDULED
ACS/SBC 10840
The FUV fluxes of Tauri stars in
the Taurus molecular cloud
Present and forthcoming ground-based and space surveys of
the T Tauri
stars in the Taurus molecular cloud
will provide information from high
energy stellar and accretion radiation
to low energy solid state and
molecular emission from the disk, making
those stars perfect
laboratories to carry out self-consistent
studies of disk physics and
evolution. We propose to complete this
wealth of information by
obtaining ACS/FUV spectra for a
significant sample of Taurus T Tauri
stars, covering a range of accretion
properties and dust evolutionary
stages. FUV fluxes carry ~ 10 - 100
more energy than X-rays into these
disks and are thus crucial gas
heating agents and key to disk dispersal
by photoevaporation.
These observations are a pre-requisite to interpret
observations with Spitzer, SOFIA, Herschel,
and ALMA, and will become
one of the important legacies of
HST to the star formation community.
ACS/SBC 10864
Mapping the Gaseous Content of Protoplanetary
and Young Planetary
Systems with ACS
One of the key problems in planetary system formation is understanding
how rapidly, and over what time
interval Jovian planets can form. Dust
in the protoplanetary
disk is critical in planetesimal formation, but it
is the gas which produces giant
planets, and which is essential for
their migration. However, compared to
data on the circumstellar dust,
information on the gas component is sparse,
especially in the
planet-formation zone. This severely limits our
ability to put
observational constraints on giant planet
formation, except to note that
the process must be largely
complete by 12 Myr, given the paucity of
Herbig Ae or
classical T Tauri stars older than 10-12 Myr. In the FUV,
photo-excited molecular hydrogen transitions
have the requisite contrast
to the stellar photosphere,
accretion shock, and reflection nebulosity,
and can be traced 50-100 AU from
the exciting stars in both envelopes
and outflow cavities and protoplanetary disks. Central disk cavities, an
expected consequence of planet
formation, larger than 0.1" are directly
detectable in HST FUV spectra, while
smaller cavities may be detected by
comparison with protoplanetary
disks which are still accreting onto
their stars. We propose augmenting
existing HST coronagraphic imagery of
6 Herbig Fe and T Tauri disks with ACS Solar-Blind Channel Lyman alpha
imagery and slitless
spectroscopy simultaneously sampling the disk in
molecular hydrogen and small-grain
reflection nebulosity. These data
will be used to quantify the amount
of vertical stratification in these
disks, to map the mass-loss geometry
from the star, and to determine
whether removal of molecular material preceds, lags, or is contemporary
with clearing of the dust.
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.
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 witin
15 Mpc, each SN stands an excellent chance of
detection with
HST and Spitzer and of resolving potential light echoes.
FLIGHT OPERATIONS SUMMARY:
Significant Spacecraft Anomalies: (The following are
preliminary reports
of potential non-nominal
performance that will be investigated.)
HSTARS:
10948 - REACQ(2,3,3) failed, scan
step limit exceeded on FGS 2
REACQ(2,3,3) at 226/20:08:58 failed due to scan step limit
exceeded on
FGS 2.
10949 - ACS 779 Fold Mechanism Move was Blocked
A
series of ACS 779 Status Buffer Messages "Fold Mechanism Move Was
Blocked" were received beginning at 20:17:06. This was the result of a
failed REACQ(2,3,3) at 20:08:58 (HSTAR 10948) which caused
the Take Data
Flag to be down when the fold mechanism move to the SBC position was
commanded.
COMPLETED OPS REQUEST:
18121-1 - Patch WF2 UIDLE
replacement htr set point, adjustment #4
COMPLETED OPS NOTES: None
SCHEDULED
SUCCESSFUL
FGS GSacq
08
08
FGS REacq
06
05
OBAD with Maneuver
28
28
SIGNIFICANT EVENTS:
The 4th in-flight adjustment of the WF/PC-II replacement
heater
temperature control was successfully
completed with the execution of Ops
Request 18121-1 at 226/14:07. All activities proceeded
nominally.
The UIDLE dead band control range was shifted from 8.7 -
9.99 to 7.83 -
9.05 degC. The behavior of the replacement
heaters under the control of
UIDLE and the optical bench temperatures will continue to
be monitored
in real-time until such time as
the new settings are functionally
verified. Another Flash Report will be
sent following this verification.
At 226/22:48:08 the replacement heaters were observed
turning on when
Bay1 fell to 7.83 degs, ~ 7
minutes later they were disables when Bay1
reached 9.05 deg as expected,
functionally verifying the patches.
-
____________________________________________________________
Lynn F. Bassford
Hubble Space Telescope
CHAMP
CHAMP Flight Operations Team Manager
Lockheed Martin
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