Daily Report # 4427

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***** # 4427

PERIOD COVERED: UT August 15, 2007 (DOY 227)

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.

NIC1 11063

NICMOS Focus Monitoring

This program is a version of the standard focus sweep used since cycle
7. It has been modified to go deeper and uses more narrow filters for
improved focus determination. For Cycle14 a new source has been added
in order to accommodate 2-gyro mode: the open cluster NGC1850. The old
target, the open cluster NGC3603, will be used whenever available and
the new target used to fill the periods when NGC3603 is not visible.
Steps: a} Use refined target field positions as determined from cycle
7 calibrations b} Use MULTIACCUM sequences of sufficient dynamic range
to account for defocus c} Do a 17- point focus sweep, +/- 8mm about
the PAM mechanical zeropoint for each cameras 1 and 2, in 1.0mm steps.
d} Use PAM X/Y tilt and OTA offset slew compensations refined from
previous focus monitoring/optical alignment activities.

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 11133

Late-Time Photometry of SN 2005hk: A New Kind of Type Ia Supernova

Our lack of understanding of Type Ia supernova {SN Ia} explosions
limits our confidence in their use for cosmology. While there is broad
agreement that these objects represent the explosions of white dwarfs,
the details of the explosion mechanism are not well- understood.
Recent observations have detected a previously unacknowledged variant
class of SNe Ia whose photometric and spectroscopic peculiarities make
them quite distinct from normal SNe Ia. These objects represent a
challenge for thermonuclear supernova models, as a complete theory of
exploding white dwarfs must allow for their existence. A particularly
well-studied example of this class of objects is the recent SN 2005hk,
whose properties in some respects resemble those of models which
invoke a subsonic burning front, called a deflagration. We propose to
test SN Ia models by obtaining late-time photometry for this extreme
SN Ia using WFPC2 and NICMOS on HST. We will accurately measure the
late-time photometric decline rate and spectral energy distribution
{SED}. These observations will allow us to test whether the ejecta
contain the large amount of oxygen predicted by certain models, the
efficiency of energy deposition by gamma rays and positrons, and
possibly detect major evolution of the SED expected due to a change in
the dominant cooling mechanism of the ejecta.

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.

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)