Status Report

NASA Hubble Space Telescope Daily Report #4214

By SpaceRef Editor
October 6, 2006
Filed under , ,
NASA Hubble Space Telescope Daily Report #4214


– Continuing to collect World Class Science

PERIOD COVERED: UT October 05, 2006 (DOY 278)


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/WFC 10633

GRB afterglows and host galaxies at very high redshifts

Cosmology is beginning to constrain the nature of the earliest stars and galaxies to form in the universe, but direct observation of galaxies at z>6 remains highly challenging due to their scarcity, intrinsically small size, and high luminosity distance. GRB afterglows, thanks to their extreme luminosities, offer the possibility of circumventing these normal constraints by providing redshifts and spectral information which couldn’t be obtained by direct observation of the hosts themselves. In addition, the association of GRBs with massive stars means that they are a tracer of star formation, and that their hosts are likely responsible for a large proportion of the ionizing radiation during that era. Our collaboration is mounting a campaign to rapidly identify and study candidate very high redshift bursts, bringing to bear a network of 2, 4 and 8m telescopes with nIR instrumentation. The capabilities of Swift to detect faint, distant GRBs, and to report accurate positions for many bursts in near real-time makes our program now feasible. HST is crucial to this endeavour, allowing us {a} to monitor the late time afterglows and hence compare them to lower-z bursts and test the use of GRBs as standard candles; and {b} characterise the basic properties, luminosities, and in some cases morphologies, of the hosts, which is essential to understanding these primordial galaxies and their relationship to other populations.

ACS/WFC 10848

Relating the host galaxies of type-2 quasars to their infrared properties

The obscured quasar population has been found to consist of a wide variety of objects. In this proposal, we wish to study the host galaxies of six z~0.6 type-2 quasars selected via their mid- infrared emission. Infrared spectra and photometry of these objects show that they include both actively star-forming and non-starforming galaxies, and have dust columns to the AGN ranging from moderate to high. We will relate the host galaxy properties to the infrared properties of these type-2 quasars, and to the host galaxies of type-1 quasars of similar redshift and bolometric luminosity. These observations will thus help us to understand how the different types of obscured quasars are related to each other, and to the normal quasar population.

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.

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.

NIC2 10906

The Fundamental Plane of Massive Gas-Rich Mergers: II. The QUEST QSOs

We propose deep NICMOS H-band imaging of a carefully selected sample of 23 local QSOs. This program is the last critical element of a comprehensive investigation of the most luminous mergers in the nearby universe, the ultraluminous infrared galaxies {ULIRGs} and the quasars. This effort is called QUEST: Quasar / ULIRG Evolutionary STudy. The high-resolution HST images of the QUEST QSOs will complement an identical set of images on the ULIRG sample obtained during Cycle 12, an extensive set of ground-based data that include long-slit NIR spectra from a Large VLT Program, and a large set of mid-infrared spectra from a Cycle 1 medium-size program with Spitzer. This unique dataset will allow us to derive with unprecedented precision structual, kinematic, and activity parameters for a large unbiased sample of objects spanning the entire ULIRG/QSO luminosity function. These data will refine the fundamental plane of massive gas-rich mergers and enable us to answer the following quesitons: {1} Do ultraluminous mergers form elliptical galaxies, and in particular, giant ellipticals? {2} Do ULIRGs evolve into optical bright QSOs? The results from this detailed study of massive mergers in the local universe will be relevant to understanding the basic physical processes involved in creating massive early-type host on the one hand, and growing/feeding embedded massive black holes on the other, in major galaxy mergers. This is an important question since 50% of cosmic star formation at high-z and most of the big BHs appear to be formed in this process.


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

HSTARS: (None)



                           SCHEDULED      SUCCESSFUL 
FGS GSacq                 09                     09 
FGS REacq                 05                     05 
OBAD with Maneuver    28                     28 


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