NASA Hubble Space Telescope Daily Report #4704

HUBBLE SPACE TELESCOPE DAILY REPORT #4704

Continuing to collect World Class Science

PERIOD COVERED: 5am September 25 – 5am September 26, 2008 (DOY 269/0900z-270/0900z)

OBSERVATIONS SCHEDULED

FGS 11213

Distances to Eclipsing M Dwarf Binaries

We propose HST FGS observations to measure accurate distances of 5 nearby M dwarf eclipsing binary systems, from which model-independent luminosities can be calculated. These objects have either poor or no existing parallax measurements. FGS parallax determinations for these systems, with their existing dynamic masses determined to better than 0.5%, would serve as model-independent anchor points for the low-mass end of the mass-luminosity diagram.

WFPC2 11113

Binaries in the Kuiper Belt: Probes of Solar System Formation and Evolution

The discovery of binaries in the Kuiper Belt and related small body populations is powering a revolutionary step forward in the study of this remote region. Three quarters of the known binaries in the Kuiper Belt have been discovered with HST, most by our snapshot surveys. The statistics derived from this work are beginning to yield surprising and unexpected results. We have found a strong concentration of binaries among low-inclination Classicals, a possible size cutoff to binaries among the Centaurs, an apparent preference for nearly equal mass binaries, and a strong increase in the number of binaries at small separations. We propose to continue this successful program in Cycle 16; we expect to discover at least 13 new binary systems, targeted to subgroups where these discoveries can have the greatest impact.

WFPC2 11130

AGNs with Intermediate-mass Black Holes: Testing the Black Hole-Bulge Paradigm, Part II

The recent progress in the study of central black holes in galactic nuclei has led to a general consensus that supermassive {10^6-10^9 solar mass} black holes are closely connected with the formation and evolutionary history of large galaxies, especially their bulge component. Two outstanding issues, however, remain unresolved. Can central black holes form in the absence of a bulge? And does the mass function of central black holes extend below 10^6 solar masses? Intermediate-mass black holes {<10^6 solar masses}, if they exist, may offer important clues to the nature of the seeds of supermassive black holes. Using the SDSS, our group has successfully uncovered a new population of AGNs with intermediate-mass black holes that reside in low-luminosity galaxies. However, very little is known about the detailed morphologies or structural parameters of the host galaxies themselves, including the crucial question of whether they have bulges or not. Surprisingly, the majority of the targets of our Cycle 14 pilot program have structural properties similar to dwarf elliptical galaxies. The statistics from this initial study, however, are really too sparse to reach definitive conclusions on this important new class of black holes. We wish to extend this study to a larger sample, by using the Snapshot mode to obtain WFPC2 F814W images from a parent sample of 175 AGNs with intermediate- mass black holes selected from our final SDSS search. We are particularly keen to determine whether the hosts contain bulges, and if so, how the fundamental plane properties of the host depend on the mass of their central black holes. We will also investigate the environment of this unique class of AGNs.

WFPC2 11289

SL2S: The Strong Lensing Legacy Survey

Recent systematic surveys of strong galaxy-galaxy lenses {CLASS, SLACS, GOODS, etc.} are producing spectacular results for galaxy masses roughly below a transition mass M~10^13 Mo. The observed lens properties and their evolution up to z~0.2, consistent with numerical simulations, can be described by isothermal elliptical potentials. In contrast, modeling of giant arcs in X-ray luminous clusters {halo masses M >~10^13 Mo} favors NFW mass profiles, suggesting that dark matter halos are not significantly affected by baryon cooling. Until recently, lensing surveys were neither deep nor extended enough to probe the intermediate mass density regime, which is fundamental for understanding the assembly of structures. The CFHT Legacy Survey now covers 125 square degrees, and thus offers a large reservoir of strong lenses probing a large range of mass densities up to z~1. We have extracted a list of 150 strong lenses using the most recent CFHTLS data release via automated procedures. Following our first SNAPSHOT proposal in cycle 15, we propose to continue the Hubble follow-up targeting a larger list of 130 lensing candidates. These are intermediate mass range candidates {between galaxies and clusters} that are selected in the redshift range of 0.2-1 with no a priori X-ray selection. The HST resolution is necessary for confirming the lensing candidates, accurate modeling of the lenses, and probing the total mass concentration in galaxy groups up to z~1 with the largest unbiased sample available to date.

WFPC2 11544

The Dynamical Legacy of Star Formation

We propose to use WFPC2 to conduct a wide-field imaging survey of the young cluster IC348. This program, in combination with archival HST observations, will allow us to measure precise proper motions for individual cluster members, characterizing the intra-cluster velocity dispersion and directly studying the dynamical signatures of star formation and early cluster evolution. Our projected astrometric precision (~1 mas in each epoch) will allow us to calculate individual stellar velocities to unprecedented precision (<0.5 mas/yr; <1 km/s) and directly relate these velocities to observed spatial substructure within the cluster. This survey will also allow us to probe small-scale star formation physics by searching for high-velocity stars ejected from decaying multiple systems, expanding our knowledge of multiplicity in dense environments, and identifying new substellar and planetary-mass cluster members based on kinematic membership tests.

WFPC2 11796

WFPC2 Cycle 16 Decontaminations and Associated Observations

This proposal is for the WFPC2 decons. Also included are instrument monitors tied to decons: photometric stability check, focus monitor, pre- and post-decon internals (bias, intflats, kspots, & darks), UV throughput check, VISFLAT sweep, and internal UV flat check.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11510 – GSAcq(1,2,1) failed to RGA Hold (Gyro Control)

Upon acquisition of signal at 269/20:33:00, the GSAcq(1,2,1) scheduled at 269/20:08:35 – 20:16:40 had failed to RGA Hold with (QF1STOPF) stop indication flag set on FGS-1.

Possible Observations affected: WFPC 45 thru 47, Proposal ID#11113.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                      SCHEDULED      SUCCESSFUL

FGS GSacq               13                   12
FGS REacq               00                   00
OBAD with Maneuver      26                   26

SIGNIFICANT EVENTS: (None)