NASA Hubble Space Telescope Daily Report #4778

HUBBLE SPACE TELESCOPE DAILY REPORT #4778

Continuing to collect World Class Science

PERIOD COVERED: 5am January 26 – 5am January 27, 2009 (DOY 026/1000z-027/1000z)

OBSERVATIONS SCHEDULED

ACS/SBC 11681

A Search for Ultraviolet Emission Filaments in Cool Core Clusters

We propose to use ACS SBC imaging to seek ultraviolet CIV emission filaments in clusters of galaxies exhibiting strong cool-core X-ray emission and optical line emission filaments. These short observations are crafted to test thermal conduction models for the filament excitation, and can significantly impact our understanding of the overall physical processes dominant in the galaxy cluster ISM.

ACS/SBC 11970

HST Observations of Titan’s Escaping Atmosphere in Transit and in Emission

We propose UV observations using the ACS/SBC of Titan’s extended escaping atmosphere for the Jan/Feb 2009 period of transits of Titan across Saturn. A combination of absorption of Saturn’s reflected solar UV emission in transit, and extended emissions primarily from H atoms away from transit, will yield new information about the structure of Titan’s extended upper atmosphere. These observations are expected to provide new constraints on theoretical models for a hydrodynamic flow of species through Titan’s exobase level, resulting from the interpretation of recent Cassini measurements at Titan.

WFPC2 11103

A Snapshot Survey of The Most Massive Clusters of Galaxies

We propose the continuation of our highly successful SNAPshot survey of a sample of 125 very X-ray luminous clusters in the redshift range 0.3-0.7. As demonstrated by the 25 snapshots obtained so far in Cycle14 and Cycle15 these systems frequently exhibit strong gravitational lensing as well as spectacular examples of violent galaxy interactions. The proposed observations will provide important constraints on the cluster mass distributions, the physical nature of galaxy-galaxy and galaxy-gas interactions in cluster cores, and a set of optically bright, lensed galaxies for further 8-10m spectroscopy. All of our primary science goals require only the detection and characterization of high-surface-brightness features and are thus achievable even at the reduced sensitivity of WFPC2. Because of their high redshift and thus compact angular scale our target clusters are less adversely affected by the smaller field of view of WFPC2 than more nearby systems. Acknowledging the broad community interest in this sample we waive our data rights for these observations.

WFPC2 11302

WFPC2 CYCLE 16 Standard Darks – Part III

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 11793

WFPC2 Cycle 16 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.

WFPC2 11966

The Recent Star Formation History of SINGS Galaxies

The Spitzer Legacy project SINGS provided a unique view of the current state of star formation and dust in a sample of galaxies of all Hubble types. This multi-wavelength view allowed the team to create current star formation diagnostics that are independent of the dust content and increased our understanding of the dust in galaxies. Even so, using the SINGS data alone we can only make rough estimates of the recent star formation history of these galaxies. The lack of high resolution observations (especially U-band and H-alpha) means that it is impossible to estimate the ages of young clusters. In addition, the low resolution of the Spitzer and ground-based observations means that what appear to be individual Spitzer sources can actually be composed of many individual clusters with varying ages. We need to know the ages, star formation histories, and extinction of these individual clusters to understand how these clusters form and age and thus influence the evolution of the galaxy. In this proposal we address this missing area of SINGS by obtaining high-resolution WFPC2 UBVI & H-alpha observations to not only accurately locate and determine the ages of the young stellar clusters in the actively star forming SINGS galaxies but to also address a variety of other scientific issues. Over 500 HST orbits and 500 hours of Spitzter observing time have been dedicated to observations of the SINGS sample. But the HST observations have not been systematic. By adding a relatively small fraction of this time for these requested observations, we will greatly enhance the legacy value of the SINGS observations by creating a uniform high resolution multi-wavelength HST archive that matches the quality of the lower resolution SINGS archive.

WFPC2 11991

Constraining the Late Time Lightcurve and Energy of GRB 090102

We propose to conduct a series of late time observations of the lightcurve of the bright gamma-ray burst GRB 090102. Declared a burst of interest by the Swift team, and with excellent broadband data covering the prompt emission (Swift and Fermi) and afterglow (Swift, TAROT, NOT, WHT, and several more), GRB 090102 offers a rare opportunity to probe the physics and energetics of GRBs. Its high energy budget (>2e53 ergs for isotropic emission) stretches plausible progenitor models, and as yet the signatures of jet-like emission have not been observed. Our late time observations will search for steepening of the afterglow due to lateral expansion of the jet. This will enable us, in tandem with the data already secured, to determine its total energy budget, and compare this to expectations for different progenitors models. HST is vital to this endeavour since it can reach depths essentially unattainable to ground based technology, while its invariant PSF will allow us to accurately remove underlying host contamination. Ultimately, the range and quality of data secured for this burst will enable us to accurately reconstruct the parameters of the explosion, and shed greater light on the physical processes which underlie the production of GRBs.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

11649 – REACQ(2,3,2) at 026/23:57:47 failed to RGA control at 027/00:01:36 with QF2STOPF and QSTOP flags set.

Observations affected: WFPC 32 to 33, proposal 11966

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                         SCHEDULED      SUCCESSFUL
FGS GSacq                05                  05
FGS REacq                07                  06
OBAD with Maneuver       22                  22

SIGNIFICANT EVENTS: (None)