Status Report

NASA Hubble Space Telescope Daily Report #4379

By SpaceRef Editor
June 8, 2007
Filed under , ,
NASA Hubble Space Telescope Daily Report #4379

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.


– Continuing to collect World Class Science

PERIOD COVERED: UT June 07, 2007 (DOY 158)


ACS/SBC 10862

Comprehensive Auroral Imaging of Jupiter and Saturn during the International Heliophysical Year

A comprehensive set of observations of the auroral emissions from Jupiter and Saturn is proposed for the International Heliophysical Year in 2007, a unique period of especially concentrated measurements of space physics phenomena throughout the solar system. We propose to determine the physical relationship of the various auroral processes at Jupiter and Saturn with conditions in the solar wind at each planet. This can be accomplished with campaigns of observations, with a sampling interval not to exceed one day, covering at least one solar rotation. The solar wind plasma density approaching Jupiter will be measured by the New Horizons spacecraft, and a separate campaign near opposition in May 2007 will determine the effect of large-scale variations in the interplanetary magnetic field {IMF} on the Jovian aurora by extrapolation from near-Earth solar wind measurements. A similar Saturn campaign near opposition in Jan. 2007 will combine extrapolated solar wind data with measurements from a wide range of locations within the Saturn magnetosphere by Cassini. In the course of making these observations, it will be possible to fully map the auroral footprints of Io and the other satellites to determine both the local magnetic field geometry and the controlling factors in the electromagnetic interaction of each satellite with the corotating magnetic field and plasma density. Also in the course of making these observations, the auroral emission properties will be compared with the properties of the near-IR ionospheric emissions {from ground-based observations} and non thermal radio emissions, from ground-based observations for Jupiter?s decametric radiation and Cassini plasma wave measurements of the Saturn Kilometric Radiation {SKR}.

ACS/SBC 11074

ACS/SBC Darks in Support of Specific SBC Science Observations

This program provides SBC DARK visits to be scheduled in conjuction with certain specific science observations which require the SBC to be turned on in the orbit preceeding the science observation.

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=3Ddate/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 11157

NICMOS Imaging Survey of Dusty Debris Around Nearby Stars Across the Stellar Mass Spectrum

Association of planetary systems with dusty debris disks is now quite secure, and advances in our understanding of planet formation and evolution can be achieved by the identification and characterization of an ensemble of debris disks orbiting a range of central stars with different masses and ages. Imaging debris disks in starlight scattered by dust grains remains technically challenging so that only about a dozen systems have thus far been imaged. A further advance in this field needs an increased number of imaged debris disks. However, the technical challege of such observations, even with the superb combination of HST and NICMOS, requires the best targets. Recent HST imaging investigations of debris disks were sample-limited not limited by the technology used. We performed a search for debris disks from a IRAS/Hipparcos cross correlation which involved an exhaustive background contamination check to weed out false excess stars. Out of ~140 identified debris disks, we selected 22 best targets in terms of dust optical depth and disk angular size. Our target sample represents the best currently available target set in terms of both disk brightness and resolvability. For example, our targets have higher dust optical depth, in general, than newly identified Spitzer disks. Also, our targets cover a wider range of central star ages and masses than previous debris disk surveys. This will help us to investigate planetary system formation and evolution across the stellar mass spectrum. The technical feasibility of this program in two-gyro mode guiding has been proven with on- orbit calibration and science observations during HST cycles 13, 14, and 15.

NIC3 11080

Exploring the Scaling Laws of Star Formation

As a variety of surveys of the local and distant Universe are approaching a full census of galaxy populations, our attention needs to turn towards understanding and quantifying the physical mechanisms that trigger and regulate the large-scale star formation rates {SFRs} in galaxies.

WFPC2 10841

A Proper Motion Search for Intermediate Mass Black Holes in Globular Clusters {2nd Epoch Observations}

Establishing the presence or absence of intermediate-mass black holes {IMBH} in globular clusters is crucial for understanding the evolution of dense stellar systems. Observationally, this search has been hampered by the low number of stars with known velocities in the central few arcseconds. This limits our knowledge of the velocity dispersion in the region where the gravitational influence of any IMBH would be felt. In Cycle 13, we successfully obtained ACS/HRC images of the centers of five carefully chosen Galactic globular clusters {GO-10401} for a new proper motion study. Although the science case was approved and the first epoch images obtained, the requested future cycle observations were not granted {due to a general policy decision based on the strong uncertainties at the time concerning the immediate future of HST}. We have now assessed the quality of the first epoch observations. The HRC resolution reveals many isolated stars in to the very center of each cluster that remained blended or unresolved in previous WFPC2 data. Given a two year baseline, we are confident that we can achieve the proper motion precision required to place strict limits on the presence of an IMBH. Therefore, we request the second-epoch, follow-up observations to GO-10401 in order to measure the proper motions of stars in our target clusters. These velocity measurements will allow us to: {i} place constraints on the mass of a central black hole in each cluster; {ii} derive the internal velocity dispersion as a function of cluster radius; {iii} verify or reject previous reports of cluster rotation; and {iv} directly measure velocity anisotropy as a function of radius. If no second epoch data are obtained then the observing time already invested in the first epoch will have been wasted.

WFPC2 10873

The Radio-quiet Jet Flow in Markarian 34

The properties of AGN jet flows are notoriously difficult to ascertain. We are currently studying jets in Seyferts by combining emission-line diagnostics with radio observations. We have devised a method of analysis which — with only modest and reasonable assumptions — leads to a physical description of the jet flow: its mass, momentum and energy flux, along with its density, velocity and Mach number. We have applied this method to a rich dataset on Markarian 78 and discovered that its jet is very weak, slow, and dense relative to the kind of jets found in radio loud AGN {Whittle \& Wilson 2004, Whittle et al 2005, 2006}. Such a difference between radio quiet and radio loud jet flows would be a major result — if it were found to be generally true. We have more modest observations of a further six Seyferts with jets, but only one of these — Mkn 34 — approaches Mkn 78 as a clean enough case to allow our full analysis. Our existing VLA and STIS data are excellent, but the HST archive emission-line and continuum images are of poor quality and low resolution. We are requesting just 3 orbits to obtain higher S/N images at high resolution {ACS/HRC} in [OIII] 5007, [OII] 3727, green and red continuum, bringing the total dataset up to a par with that of Mkn 78. We will then be able to apply our full analysis to determine the nature of the jet flow in this second radio quiet AGN.


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

HSTARS: 10853 – GSACQ(2,1,1) failed GSACQ(2,1,1) at 159/02:18:36 failed to RGA control at 02:22:40 with QF2STOPF and QSTOP flags set.

10854 – GSACQ(1,0,1) failed GSACQ(1,0,1) at 159/03:56:14 failed to RGA control with QF1STOPF and QSTOP flags set. #44 commands did not update since previous REACQ(1,2,1) at 00:31:50.

COMPLETED OPS REQUEST: 18098-1 – Dump NICMOS memory after suspend @ 158/1054z 18099-0 – NICMOS Suspend Recovery @ 158/2005z

                       SCHEDULED      SUCCESSFUL

FGS GSacq               08                  06

FGS REacq               05                  05

OBAD with Maneuver 26                  26

COMPLETED OPS NOTES: 1615-0 – Exec 272 during NICMOS Suspend @ 158/1230z


Flash Reports

NICMOS suspended at 158/05:14:05 due to Filter Wheel #2 move out of tolerance. HST was in an LOS at the time of the anomaly, and engineering data has been dumped and is in the process of being analyzed.

NICMOS Recovery Complete: NICMOS successfully recovered to Operate mode at 158/18:42z. The NICMOS Filter Wheel #2 moved back to its blank position as expected. The PAM was moved to its intermediate position, PAM I at 158/20:09. NICMOS appears to be operating nominally.

At ~159/2:15 UTC several NICMOS observations (accums on cameras 1-3) were successfully collected and dumped to the SSR. No anomalous behavior was observed.

SpaceRef staff editor.