NASA Hubble Space Telescope Daily Report #4310

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.

HUBBLE SPACE TELESCOPE DAILY REPORT # 4310

– Continuing to collect World Class Science

PERIOD COVERED: UT March 01, 2007 (DOY 060)

OBSERVATIONS SCHEDULED

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 11050

ACS UV contamination monitor

The observations consist of imaging and spectroscopy with SBC of the cluster NGC 6681 in order to monitor the temporal evolution of the UV sensitivity of the SBC.

ACS/SBC 11056

Improved Sensitivity SBC Prisms

The flux calibration of the SBC {PR110L and PR130L} will be improved by observing for each prism white dwarf standards {WD1657+343 and LTT9491}. The blue standard star WD1657+343 has previously been observed with ACS/SBC and will serve as a reference point to track time dependent variations. LTT9491 is much redder and thus will be used to investigate the sensitivity curve of ?red? targets to check for a potential red leak of the SBC. Additionally, LTT9491 shows various strong absorption lines which can be used to confirm the wavelength calibration of the PR110L and PR130L prisms. The standard stars are observed at a variety of pointings across the SBC detector in order to map spatial variations. LTT9491 will also be observed with ACS/HRC PR200L to obtain an improved flux calibration from about 1800 A to 4000 A.

FGS 10931

Dynamical Masses and Radii of Four White Dwarf Stars

We will use FGS1R in its high angular resolution observing mode (TRANS) to resolve the white dwarf binary systems. Each exposure will be comprised of about 20 scans. The interferograms derived from each scan will be cross- correlated and co-added to yield a high SNR. To further surpress the noise (these targets are near the FGS’s faint limiting magnitude), the co-added inteferograms will be carefully smoothed by being represented as a piece-wise We will use FGS1R in its high angular resolution observing mode (TRANS) to resolve the white dwarf binary systems. Each exposure will be comprised of about 20 scans. The interferograms derived from each scan will be cross-correlated and co-added to yield a high SNR. To further surpress the noise(these targets are near the FGS’s faint limiting magnitude), the co-added inteferograms will be carefully smoothed by being represented as a piece-wise smooth segmanted polynomial. These observations will yield the separation and position angle of the binary components, as well as the brightness of each. In addition, the binary and field stars simultaneously in the FGS FOV will be observed in POS mode to accurately determine the relative positions of the stars. This will facilitate the construction of an inertial reference frame for the binary, thereby allowing the relative orbit that will be ultimately determined from the TRANS data to be converted into a physical orbit. This will allow us to determine the relative mass of each white dwarf in the binarty system. In addition, the POS mode data will give the proper motion and parallax of the binary, which will allow us to compute the mass and radius of each white dwarf.

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 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.

NIC3 10836

The Red Sequence at 1.3 < z < 1.4 in Galaxy Clusters

We propose to obtain NIC3/F160W imaging of three new IRAC-selected galaxy clusters at 1.3 < z < 1.5. In combination with deep ACS/F850LP images being obtained in Cycle 14, the resulting precision photometry in a rest ~U - R color will allow us to construct color- magnitude diagrams which can be used to measure the slope and scatter in the red sequence galaxies, thereby constraining the history of star formation in the early-type galaxies. The number of morphologically-selected early-type galaxies more luminous than L* will allow us to test the predictions of the hierarchical merging scenario for galaxy formation in clusters at the highest available redshifts in galaxy clusters.

WFPC2 10890

Morphologies of the Most Extreme High-Redshift Mid-IR-Luminous Galaxies

The formative phase of the most massive galaxies may be extremely luminous, characterized by intense star- and AGN-formation. Till now, few such galaxies have been unambiguously identified at high redshift, restricting us to the study of low-redshift ultraluminous infrared galaxies as possible analogs. We have recently discovered a sample of objects which may indeed represent this early phase in galaxy formation, and are undertaking an extensive multiwavelength study of this population. These objects are bright at mid-IR wavelengths {F[24um]>0.8mJy}, but deep ground based imaging suggests extremely faint {and in some cases extended} optical counterparts {R~24-27}. Deep K-band images show barely resolved galaxies. Mid-infrared spectroscopy with Spitzer/IRS reveals that they have redshifts z ~ 2-2.5, suggesting bolometric luminosities ~10^{13-14}Lsun! We propose to obtain deep ACS F814W and NIC2 F160W images of these sources and their environs in order to determine kpc-scale morphologies and surface photometry for these galaxies. The proposed observations will help us determine whether these extreme objects are merging systems, massive obscured starbursts {with obscuration on kpc scales!} or very reddened {locally obscured} AGN hosted by intrinsically low-luminosity galaxies.

WFPC2 11029

WFPC2 CYCLE 15 Intflat Linearity Check and Filter Rotation Anomaly Monitor

Intflat observations will be taken to provide a linearity check: the linearity test consists of a series of intflats in F555W, in each gain and each shutter. A combination of intflats, visflats, and earthflats will be used to check the repeatability of filter wheel motions. {Intflat sequences tied to decons, visits 1-18 in prop 10363, have been moved to the cycle 15 decon proposal xxxx for easier scheduling.} Note: long-exposure WFPC2 intflats must be scheduled during ACS anneals to prevent stray light from the WFPC2 lamps from contaminating long ACS external exposures.

WFPC2 11096

Hubble Heritage imaging of Jupiter during the New Horizons encounter HST Proposal 11096

WFPC2 images of Jupiter in Feb 2007 in support of New Horizons flyby of Jupiter. This Hubble Heritage DD program is working in concert with the existing GO programs by John Clarke {10862} and John Spencer {10871}.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10723 – GSACQ(2,1,2) failed, Search Radius Limit Exceeded on FGS 2 GSACQ(2,1,2) at 060/11:52:07 failed due to Search Radius Limit Exceeded on FGS 2 at 11:57:44.

10724 – GSAcq (2,1,1) results in Fine Lock Back-up (2,0,2) At 061/02:29:23 GSAcq (2,1,1) scheduled from 061/02:26:00-02:33:12 resulted in Fine Lock Back-up (2,0,2) using FGS 2, due to (QF1STOPF) stop flag indication on the secondary FGS. OBAD #1 RSS: 755.71

OBAD #2 RSS: 12.44

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                       SCHEDULED      SUCCESSFUL     
FGS GSacq               12                   12 
FGS REacq               02                   02               
OBAD with Maneuver 28                   28 

SIGNIFICANT EVENTS: (None)