Date: October 27th 2006

HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science

DAILY REPORT # 4226

PERIOD COVERED: UT October 24, 2006 (DOY 297)

OBSERVATIONS SCHEDULED

ACS/HRC 10851

Solving the Riddle of the Red Rectangle: Proper Motion Study of a Bipolar Nebula around a Binary

We propose to use ACS to obtain second-epoch, high spatial-resolution images of the nearest Pre-Planetary nebula, the Red Rectangle {RR} The RR is a Rosetta Stone for testing our understanding of binarity in the evolution of AGB stars to bipolar planetary nebulae, because it is a known binary with well determined orbital and circumbinary disk characteristics, and because of its proximity {330-700 pc} Recent analysis of archival STIS data shows evidence for outflow motion of about 100 km/s Thus, 2nd epoch observations, in combination with those of 8 years ago, will yield a direct detection of proper motion of sharp nebular structures and the overall expansion rate of this nebula The observations will therefore detect and characterise for the first time, the outflow motions of a {possibly} disk-collimated outflow from an evolved binary shaping a bipolar nebula Deep narrow-band imaging of the RR using the HRC and WFC with the F658N filter will be used to trace H-alpha emission in the central and distant parts of RR, as a probe of the shocked gas We will run numerical simulations of two currently competing models for shaping the RR, using the FLASH MHD code This code has been implemented on the JPL supercomputer to study interacting wind processes in the formation of pre-planetary and planetary nebulae The model predictions of the proper motion vectors will be compared to the observed values, and we will investigate whether tuning of the model parameters is adequate to find fits to the data, or these models have to be abandoned in favor of new ones This study will help to improve our currently very limited understanding of the role of binarity in the tranformation of AGB stars to planetary nebulae

ACS/HRC 10878

An ACS Prism Snapshot Survey for z~2 Lyman Limit Systems

We propose to conduct a spectroscopic survey of Lyman limit absorbers at redshifts 1 7 < z < 2 2, using ACS/HRC and the PR200L prism We have selected 100 quasars at 2 3 < z < 2 6 from the Sloan Digital Sky Survey Spectroscopic Quasar sample, for which no BAL signature is found at the QSO redshift and no strong metal absorption lines are present at z > 2 3 along the lines of sight The survey has three main observational goals First, we will determine the redshift frequency dN/dz of the LLS over the column density range 16 3

ACS/WFC 10816

The Formation History of Andromeda's Extended Metal-Poor Halo

We propose deep ACS imaging in the outer spheroid of the Andromeda galaxy, in order to measure the star formation history of its true halo For the past 20 years, nearly all studies of the Andromeda "halo" were focused on the spheroid within 30 kpc of the galaxy's center, a region now known to host significant substructure and populations with high metallicity and intermediate ages However, two groups have recently discovered an extended metal-poor halo beyond 30 kpc; this population is distinct in its surface-brightness profile, abundance distribution, and kinematics In earlier cycles, we obtained deep images of the inner spheroid {11 kpc on the minor axis}, outer disk {25 kpc on the major axis}, and giant tidal stream, yielding the complete star formation history in each field We now propose deep ACS imaging of 4 fields bracketing this 30 kpc transition point in the spheroid, so that the inner spheroid and the extended halo populations can be disentangled, enabling a reconstruction of the star formation history in the halo A wide age distribution in the halo, as found in the inner spheroid, would imply the halo was assembled through ongoing accretion of satellite galaxies, while a uniformly old population would be a strong indication that the halo was formed during the early rapid collapse of the Andromeda proto-galaxy

ACS/WFC/NIC3 10632

Searching for galaxies at z>6 5 in the Hubble Ultra Deep Field

We propose to obtain deep ACS {F606W, F775W, F850LP} imaging in the area of the original Hubble Ultra Deep Field NICMOS parallel fields and - through simultaneous parallel observations - deep NICMOS {F110W, F160W} imaging of the ACS UDF area Matching the extreme imaging depth in the optical and near-IR bands will result in seven fields with sufficiently sensitive multiband data to detect the expected typical galaxies at z=7 and 8 Presently no such a field exist Our combined optical and near-IR ultradeep fields will be in three areas separated by about 20 comoving Mpc at z=7 This will allow us to give a first assessment of the degree of cosmic variance If reionization is a process extending over a large redshift interval and the luminosity function doesn't evolve strongly beyond z=6, these data will allow us to identify of the order of a dozen galaxies at 6 56 5 Conversely, finding fewer objects would be an indication that the bulk of reionization is done by galaxies at z=6 By spending 204 orbits of prime HST time we will capitalize on the investment of 544 prime orbits already made on the Hubble Ultra Deep Field {UDF} We have verified that the program as proposed is schedulable and that it will remain so even if forced to execute in the 2-gyro mode The data will be non-proprietary and the reduced images will be made public within 2 months from the completion of the observations

FGS 10989

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars These companions were originally detected by radial velocity techniques We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al 2004}, allowing us to determine companion masses Extrasolar planet masses assist in two ongoing research frontiers First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA

FGS 11018

Long Term Stability of FGS1r in Position Mode

It is known from our experience with FGS3, and later with FGS1r, that an FGS on orbit experiences long term evolution, presumably due to disorption of water from the instrument's graphite epoxy composits This manifests principly as a change in the plate scale and secondarily as a change in the geometric distortions These effects are well modeled by adjustments to the rhoA and kA parameters which are used to transform the star selector servo angles into FGS {x, y} detector space coordinates By observing the relative positions of selected stars in a standard cluster at a fixed telescope pointing and orientation, the evolution of rhoA and kA can be monitored and calibrated to preserve the astrometric performance of FGS1r

NIC1/NIC2/NIC3 8793

NICMOS Post-SAA calibration - CR Persistence Part 4

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

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}

NIC2, ACS/WFC 10802

SHOES-Supernovae, HO, for the Equation of State of Dark energy

The present uncertainty in the value of the Hubble constant {resulting in an uncertainty in Omega_M} and the paucity of Type Ia supernovae at redshifts exceeding 1 are now the leading obstacles to determining the nature of dark energy We propose a single, integrated set of observations for Cycle 15 that will provide a 40% improvement in constraints on dark energy This program will observe known Cepheids in six reliable hosts of Type Ia supernovae with NICMOS, reducing the uncertainty in H_0 by a factor of two because of the smaller dispersion along the instability strip, the diminished extinction, and the weaker metallicity dependence in the infrared In parallel with ACS, at the same time the NICMOS observations are underway, we will discover and follow a sample of Type Ia supernovae at z > 1 Together, these measurements, along with prior constraints from WMAP, will provide a great improvement in HST's ability to distinguish between a static, cosmological constant and dynamical dark energy The Hubble Space Telescope is the only instrument in the world that can make these IR measurements of Cepheids beyond the Local Group, and it is the only telescope in the world that can be used to find and follow supernovae at z > 1 Our program exploits both of these unique capabilities of HST to learn more about one of the greatest mysteries in science

WFPC2 10745

WFPC2 CYCLE 14 INTERNAL MONITOR

This calibration proposal is the Cycle 14 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

FLIGHT OPERATIONS SUMMARY:

Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated )

HSTARS: 10485 - GSAcq(1,3,1) failed to RGA Control Upon acquisition of signal at 298/00:43:39, GSAcq(1,3,1) scheduled at 298/00:43:34 - 00:51:38 was observed to have failed to RGA Hold due to search radius limit exceeded on FGS-3 One 486 ESB "a05" (FGS Coarse Track failed - Search Radius Limit Exceeded) was received Pre-acquisition OBAD1 attitude error correction (RSS) value not available due to LOS OBAD2 had (RSS) value of 16 98 arcseconds Post-acquisition OBAD/MAP had (RSS) value of 2991 48 arcseconds

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                      SCHEDULED      SUCCESSFUL

FGS GSacq 09 08 FGS REacq 04 04 OBAD with Maneuver 26 26

SIGNIFICANT EVENTS: (None)

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