Status Report

NASA Hubble Space Telescope Daily Report #4011

By SpaceRef Editor
December 20, 2005
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NASA Hubble Space Telescope Daily Report #4011
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HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT #4011

PERIOD COVERED: UT December 19, 2005 (DOY 353)

OBSERVATIONS SCHEDULED

ACS/HRC 10516

Host Galaxies of Reverberation-Mapped AGNs

We propose to obtain unsaturated ACS high-resolution images of four reverberation-mapped active galactic nuclei in order to remove the point-like nuclear light from each image, thus yielding a “nucleus-free” image of the host galaxy. This will allow investigation of host galaxy properties: our particular interest is determination of the host-galaxy starlight contribution to the reverberation-mapping observations. This is necessary {1} for accurate determination of the relationship between the AGN nuclear continuum flux and the size of the broad Balmer-line emitting regions of AGNs, which is important because this relationship is used in estimating black hole masses for large samples of QSOs, and {2} for accurate determination of the bolometric luminosity of the AGN proper. In a Cycle 12 SNAP program, we obtained images of 14 of the 36 reverberation-mapped AGNs for this purpose. This additional request is to complete this program through observations of the four important remaining sources.

ACS/HRC/WFC 10729

ACS CCDs daily monitor

This program consists of a set of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. The files, biases and dark will be used to create reference files for science calibration. This programme will be for the entire lifetime of ACS. Changes from cycle 13:- The default gain for WFC is 2 e-/DN. As before bias frames will be collected for both gain 1 and gain 2. Dark frames are acquired using the default gain {2}. This program cover the period Oct, 2 2005- May, 29-2006. The second half of the program has a different proposal number: 10758.

ACS/WFC 10582

Probing The Galaxy-wide Globular Cluster – Low Mass X-ray Binary Connection in Early-type Galaxies

The combination of high-resolution imaging from Hubble {HST} and Chandra {CXO} has completely revolutionized our understanding of extragalactic low-mass X-ray binaries {LMXBs} and globular clusters {GCs}; however, studies have been limited by short X-ray exposures and relatively small fields. NGC 4697 amd NGC 4365 are relatively simple elliptical galaxies in the X- ray that will have deep CXO observations. We propose ACS observations in six flanking fields per galaxy to provide a study of the GC-LMXB connection in normal early-type galaxies with unprecedented depth, spatial resolution and areal coverage. Combined with existing central field observations, we will detect ~900 and ~2700 GCs GCs in most of NGC 4697 and all of NGC 4365. These two galaxies will have the greatest number of detected GC-LMXBs to date {~70 & 120}. We will measure the fraction of LMXBs found in GCs, and the fraction of GCs which contain LMXBs, as a function of X-ray luminosity, galactocentric distance, color, GC half-light radius, and local GC specific frequency. We will test existing models of GC formation/evolution and LMXB formation/evolution. Using the radial profile of optical light, GCs, and LMXBS, we will determine the percentage of field LMXBs which may have originated in GCs.

ACS/WFC/NIC3/WFPC2 10530

Probing Evolution And Reionization Spectroscopically {PEARS}

While imaging with HST has gone deep enough to probe the highest redshifts, e.g. the GOODS survey and the Ultra Deep Field, spectroscopic identifications have not kept up. We propose an ACS grism survey to get slitless spectra of all sources in a wide survey region {8 ACS fields} up to z =27.0 magnitude, and an ultradeep field in the HUDF reaching sources up to z =28 magnitude. The PEARS survey will: {1} Find and spectrocopically confirm all galaxies between z=4-7. {2} Probe the reionization epoch by robustly determining the luminosity function of galaxies and low luminosity AGNs at z = 4 – 6. With known redshifts, we can get a local measure of star formation and ionization rate in case reionization is inhomogeneous. {3} Study galaxy formation and evolution by finding galaxies in a contiguous redshift range between 4 < z < 7, and black hole evolution through a census of low-luminosity AGNs. {4} Get a robust census of galaxies with old stellar populations at 1 < z < 2.5, invaluable for checking consistency with heirarchical models of galaxy formation. Fitting these galaxies' spectra will yield age and metallicity estimates. {5} Study star-formation and galaxy assembly at its peak at 1< z < 2 by identifying emission lines in star-forming galaxies, old populations showing the 4000A break, and any combination of the two. {6} Constrain faint white dwarfs in the Galactic halo and thus measure their contribution to the dark matter halo. {7} Derive spectro-photometric redshifts by using the grism spectra along with broadband data. This will be the deepest unbiased spectroscopy yet, and will enhance the value of the multiwavelength data in UDF and the GOODS fields to the astronomical community. To this end we will deliver reduced spectra to the HST archives.

NIC3/ACS/WFC 10504

Characterizing the Sources Responsible for Cosmic Reionization

Our group has demonstrated the role that massive clusters, acting as powerful cosmic lenses, can play in constraining the abundance and properties of low-luminosity star-forming sources beyond z~6; such sources are thought to be responsible for ending cosmic reionization. The large magnification possible in the critical regions of well-constrained clusters brings sources into view that lie at or beyond the limits of conventional exposures such as the UDF, as well as those in imaging surveys being undertaken with IRAC onboard Spitzer. We have shown that the combination of HST and Spitzer is particularly effective in delivering the physical properties of these distant sources, constraining their mass, age and past star formation history. Indirectly, we therefore gain a valuable glimpse to yet earlier epochs. Recognizing the result {and limitations} of the UDF exposure, we propose a systematic search through 6 lensing clusters with ACS and NICMOS for further z~6-7 sources in conjunction with existing deep IRAC data. Our survey will mitigate cosmic variance and extend the search both to lower luminosities and, by virtue of the NICMOS/IRAC combination, to higher redshift. The goal is to count and characterize representative sources at z~6-10 and to delineate the redshift range of activity for the planning of future observations.

NICMOS 8791

NICMOS Post-SAA calibration – CR Persistence Part 2

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.

WFPC2 10748

WFPC2 CYCLE 14 Standard Darks

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.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS: 10058 – Guide Star Acquisition Results in Fine Lock Back-up @ 354/05:47:00z GSacq(2,3,2) at 354/05:47:00 results in Fine Lock Back-up on FGS3 due to Scan Step Limit Exceeded on FGS2. Previous OBAD was successful with minimal RSS error of 9.97 arc seconds. ACS observations #s 39 and 40 may be affected.

COMPLETED OPS REQUEST: (None)

COMPLETED OPS NOTES: (None)

                        SCHEDULED      SUCCESSFUL
FGS GSacq               09                    09
FGS REacq               06                     06
OBAD with Maneuver  30                    30

SIGNIFICANT EVENTS: (None)

SpaceRef staff editor.