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)