Notice: For the foreseeable future, the daily reports may contain

apparent discrepancies between some proposal descriptions and the listed

instrument usage. This is due to the conversion of previously approved

ACS WFC or HRC observations into WFPC2, or NICMOS observations

subsequent to the loss of ACS CCD science capability in late January.

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT      # 4357

PERIOD COVERED: UT May 07, 2007 (DOY 127)

OBSERVATIONS SCHEDULED

WFPC2 10800

Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have

relatively fragile test particles which can be used as tracers of the

early dynamical evolution of the outer Solar System. We propose to

continue a Snapshot program using the ACS/HRC that has a demonstrated

discovery potential an order of magnitude higher than the HST

observations that have already discovered the majority of known

transneptunian binaries. With this continuation we seek to reach the

original goals of this project: to accumulate a sufficiently large

sample in each of the distinct populations collected in the Kuiper Belt

to be able to measure, with statistical significance, how the fraction

of binaries varies as a function of their particular dynamical paths

into the Kuiper Belt. Today's Kuiper Belt bears the imprints of the

final stages of giant-planet building and migration; binaries may offer

some of the best preserved evidence of that long-ago era.

WFPC2  10832

Solving the microlensing puzzle: An HST high-resolution imaging approach

We propose to use the HST Advanced Camera for Surveys High Resolution

Channel to obtain high resolution imaging data for 10 bona-fide LMC

microlensing events seen in the original MACHO survey. The purpose of

this survey will be to assess whether or not the lens and source stars

have separated enough to be resolved since the original microlensing

event took place - about a decade has passed since the original MACHO

survey and the HST WFPC2 follow-up observations of the microlensing

events. If the components of the lensing event are resolved, we will

determine the apparent magnitude and color of both the lens and the

source stars. These data, in combination with Spitzer/IRAC data and

Magellan near-IR JHK data, will be used to ascertain the basic

properties of the lens stars. With the majority of the microlensing

events in the original MACHO survey observed at the highest spatial

resolution currently possible, we will be able to draw important

conclusions as to what fraction of these events have lenses which belong

to some population of dwarf stars in the disk and what fraction must be

due to lenses in the halo or beyond. These data will greatly increase

our understanding of the structure of the Galaxy by characterizing the

stellar population responsible for the gravitational microlensing.

WFPC2  10877

A Snapshot Survey of the Sites of Recent, Nearby Supernovae

During the past few years, robotic {or nearly robotic} searches for

supernovae {SNe}, most notably our Lick Observatory Supernova Search

{LOSS}, have found hundreds of SNe, many of them in quite nearby

galaxies {cz < 4000 km/s}. Most of the objects were discovered before

maximum brightness, and have follow-up photometry and spectroscopy; they

include some of the best-studied SNe to date. We propose to conduct a

snapshot imaging survey of the sites of some of these nearby objects, to

obtain late-time photometry that {through the shape of the light and

color curves} will help reveal the origin of their lingering energy. The

images will also provide high-resolution information on the local

environments of SNe that are far superior to what we can procure from

the ground. For example, we will obtain color-color and color-magnitude

diagrams of stars in these SN sites, to determine the SN progenitor

masses and constraints on the reddening. Recovery of the SNe in the new

HST images will also allow us to actually pinpoint their progenitor

stars in cases where pre- explosion images exist in the HST archive.

This proposal is an extension of our successful Cycle 13 snapshot survey

with ACS. It is complementary to our Cycle 15 archival proposal, which

is a continuation of our long-standing program to use existing HST

images to glean information about SN environments.

WFPC2  11024

WFPC2 CYCLE 15 INTERNAL MONITOR

This calibration proposal is the Cycle 15 routine internal monitor for

WFPC2, to be run weekly to monitor the health of the cameras. A variety

of internal exposures are obtained in order to provide a monitor of the

integrity of the CCD camera electronics in both bays {both gain 7 and

gain 15 -- to test stability of gains and bias levels}, a test for

quantum efficiency in the CCDs, and a monitor for possible buildup of

contaminants on the CCD windows. These also provide raw data for

generating annual super-bias reference files for the calibration

pipeline.

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 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

images. Each observation will need its own CRMAP, as different SAA

passages leave different imprints on the NICMOS detectors.

NIC1/NIC3 10924

Constraints on the Assembly and Dynamical Masses of z~2 Galaxies

We propose deep NICMOS/NIC2 F160W imaging of seven star-forming galaxies

at z~2. These galaxies comprise an entirely unique sample, with not only

redshifts measured from optical and near-IR spectra, but also

SINFONI/VLT near-IR integral field spectroscopic measurements providing

kinematic maps of H-alpha emission out to radii of >=10 kpc. We aim to

determine the dynamical masses and evolutionary states of these systems,

as part of the larger goal of understanding how mass is assembled in

distant galaxies. In order to interpret our novel H-alpha integral field

maps in terms of mass, we require detailed knowledge of the structural

parameters of our target objects at rest-frame optical wavelengths and

on ~1 kpc scales. We want to establish if the mass is distributed in a

disk, bulge, or merging sub-units, and if we can detect tidal features

associated with a merger. F160W imaging with NICMOS/NIC2 provides the

perfect combination of sensitivity and resolution to address these

questions, and arrive at the fundamental quantity: the dynamical mass.

NIC2 10849

Imaging Scattered Light from Debris Disks Discovered by the Spitzer

Space Telescope around 21 Sun-like Stars

We propose to use the high-contrast capability of the NICMOS coronagraph

to image a sample of newly discovered circumstellar disks associated

with Sun-like stars. These systems were identified by their strong

thermal infrared {IR} emission with the Spitzer Space Telescope as part

of the Spitzer Legacy Science program titled "The Formation and

Evolution of Planetary Systems" {FEPS, P.I.: M.Meyer}. Modeling of the

thermal excess emission from the spectral energy distributions alone

cannot distinguish between narrowly confined high-opacity disks and

broadly distributed, low-opacity disks. By resolving light scattered by

the circumstellar material, our proposed NICMOS observations can break

this degeneracy, thus revealing the conditions under which planet

formation processes are occuring or have occured. For three of our

IR-excess stars that have known radial-velocity planets, resolved

imaging of the circumstellar debris disks may further offer an

unprecedented view of planet-disk interactions in an extrasolar

planetary system. Even non-detections of the light scattered by the

circumstellar material will place strong constraints on the disk

geometries, ruling out disk models with high optical depth. Unlike

previous disk imaging programs, our program contains a well-defined

sample of ~1 solar mass stars covering a range of ages from 3 Myr to 3

Gyr, thus allowing us to study the evolution of disks from primordial to

debris for the first time. The results from our program will greatly

improve our understanding of the architecture of debris disks around

Sun-like stars, and will create a morphological context for the

existence of our own solar system. This proposal is for a continuation

of an approved Cycle 14 program {GO/10527, P.I.: D. Hines}.

WFPC2 11002

A Census of LIRGs in Clusters of Galaxies in the First Half of the

Universe from the IRAC Shallow Survey

The incidence of LIRGs and ULIRGs is roughly two orders of magnitude

higher in the field at redshift z > 1, and at these redshifts such

objects dominate the global star formation activity. Mergers which fuel

such activity might be expected to enhance the frequency of LIRGs in

dense environments. We propose to use MIPS to obtain a census of LIRGs

in z > 1 galaxy clusters from a well defined sample found in the IRAC

Shallow Survey. Supporting IRAC and HST ACS data are also requested.

WFPC2 11023

WFPC2 CYCLE 15 Standard Darks - part 1

This dark calibration program obtains dark frames every week in order to

provide data for the ongoing calibration of the CCD dark current rate,

and to monitor and characterize the evolution of hot pixels. Over an

extended period these data will also provide a monitor of radiation

damage to the CCDs.

WFPC2 11075

The 2006 outburst of RS Oph - Second epoch HST observations of evolving

structures

We propose to use second epoch HST DD time to perform high resolution

optical imaging of the 2006 outburst of the Recurrent Nova RS Ophiuchi,

which underwent its last recorded outburst in 1985. In this system, high

velocity ejecta from a WD near the Chandrasekhar mass impact the

companion red giant wind, setting up shock systems analogous to those in

SNR. Our first epoch observations in July 2006 {day 155} revealed for

the first time what appear to be the sub-arcsecond optical counterparts

of the "jets" we have observed in the radio. A striking similarity to

the double rings of SN 1987A is however evident. In addition, previously

unseen structures ~1 arcsec to the East and South are apparent. In

addition to determining the true source geometry and disentagling the

contributions different regions of the source make to unresolved

spectra, the specific aims of our second epoch observations are to

determine {i} the expansion rate of the inner extended features,

allowing comparison with simple shock models and helping to constrain

the distance to RS Oph; {ii} whether the eastern "arc" and southern

"blob" show any motion, helping to determine whether they are the result

of previous outbursts, and {iii} the rate of change of emission in the

observed lines, for direct comparison with shock models, and also to

compare with the overall changes in line fluxes seen in infrared,

optical and uv spectroscopy. Our work on RS Oph has far wider-ranging

importance which includes furthering our understanding of the outbursts

of novae, the structure of red giant winds, jet ejection and collimation

in astrophysical sources, the progenitors of Type Ia supernovae and the

evolution of supernova remnants. Continued HST observations complement

our multi-frequency observing campaign, in particular our unrivalled

coverage of this event with VLBI.

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:

18072-1 - PCS KF OOT Support

18069-3 - MSS/CSS/Gyro2 KF Initialization Convergence Testing for SMS 127

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL

FGS GSacq               07                  07               

FGS REacq               07                  07              

OBAD with Maneuver 27                  27              

SIGNIFICANT EVENTS:

Evaluation of Universal Kalman Filter performance continued. Details

follow.

The KF was halted at 127/18:15 (OR 18069-3). The filter was restarted at

127/18:18 with the CSS disabled, the Gyro2 input enabled, during orbit

day, during a vehicle slew and during an M2G guiding interval and during

a slow changing B-field. All UKF parameters showed nominal operation.

The test was an MSS/Gyro2 Initialization test case during a vehicle slew

with a slow changing B-field (M_G2_IVS, Test #35).

The KF was reconfigured and restarted at 127/19:14 with the CSS and both

gyro inputs disabled to leave the filter in an MSS only configuration.

This configuration is to help provide a earlier baseline set of data for

PCS analysis and it will remain the default configuration outside of

other KF convergence testing for the remainder of the week.