Status Report

NASA Hubble Space Telescope Daily Report #4247

By SpaceRef Editor
November 27, 2006
Filed under , ,
NASA Hubble Space Telescope Daily Report #4247


– Continuing to collect World Class Science

PERIOD COVERED: UT November 27, 2006 (DOY 331)



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 May, 31 2006- Oct, 1-2006. The first half of the program has a different proposal number: 10729.

ACS/SBC 10814

The Masses for ultraluminous X-ray sources

Ultraluminous X-ray sources are non-nuclear sources in normal disk galaxies that are either stellar mass black holes that are super-Eddington emitters, or 1E3-1E4 Msolar black holes emitting normally. We can distinguish between these models by obtaining constraints for the mass of the primary, which can be accomplished through UV objective prism spectra. This strategy begins with the optical identification of the secondary and identification of its spectral type in order to determine its mass and the Roche Lobe radius. Secondly, we need to determine whether an accretion disk is present and if its high ionization UV line luminosities point to a stellar mass black hole or a more massive object. Finally, if the black hole is 1E3-1E4 Msolar, the orbital velocity of the secondary is so large that a Doppler shift will be detectable, even at the modest resolution of the prism.

ACS/WFC 10881

The Ultimate Gravitational Lensing Survey of Cluster Mass and Substructure

We propose a systematic and detailed investigation of the mass, substructure, and thermodynamics of one hundred X-ray luminous galaxy clusters at 0.15 < z < 0.3. The primary goal is to test our recent suggestion that this population is dominated by dynamically immature disturbed clusters, and that the observed mass-temperature relation suffers strong structural segregation. If confirmed, this would represent a paradigm shift in our observational understanding of clusters, that were hitherto believed to be dominated by mature, undisturbed systems. The key observation to this endeavor is Hubble imaging of cluster cores to identify robustly tangential and radial multiple arcs and measure the shape of faint galaxies. These strong and weak lensing signals will give an accurate measure of the total mass and structure of the dark matter distribution that we will subsequently compare with X-ray and Sunyaev Zeldovich Effect observables. The broader applications of our project include 1} the calibration of mass-temperature and mass-SZE scaling relations which will be critical for the calibration of proposed dark energy experiments, and 2} the low redshift baseline study of the demographics of massive clusters to aid interpretation of future high redshift {z>1} cluster samples. For this ultimate cluster survey, we request ACS SNAPSHOTS through the F606W filter drawn from a target list of 143 clusters.

ACS/WFC 11003

Mixing It Up : Gas, Stars, Starbirth, and AGN in a Supercluster at z = 0.9

We propose a joint Spitzer/HST program to map the best-studied large scale structure at high redshift — a massive twelve-cluster supercluster at z = 0.9 which extends 15 Mpc x 100 Mpc. Because clusters are actively forming at this redshift, and significant evolution has already been observed in their galaxy populations, this survey will provide the crucial link between large scale structure and galaxy-scale physics. The supercluster is already the subject of a multi-faceted program including {1} deep r’i’z’K imaging from the Palomar 5-m to measure optical/near-IR colors, {2} spectroscopy with DEIMOS on the Keck 10-m to measure stellar content, [OII] equivalent widths, and internal velocities for over 330 supercluster members, {3} high-angular-resolution Chandra and VLA observations to study the starburst and AGN populations, and {4} an 80 ksec XMM observation to quantify the cluster gas properties and the amount of diffuse emission from the low-density filaments. The proposed 3.6-24 micron mapping is an essential complement to this program because it provides more accurate measures of stellar mass, star formation rate, and nuclear/starburst activity across the entire structure. The ACS observations will provide equal detail on galaxy structural properties and morphology. Together, the deep mid-infrared observations and the high-angular-resolution HST imagery {along with our coordinated ground and space-based data} will allow us to measure the stellar mass function, stellar population ages, and star formation rates over the full range of environmental densities; use galaxy morphology to determine what type of galaxies host AGN and which physical processes are responsible for gas-fueling events; quantify the IR/radio/X-ray correlations at z = 0.9; and determine the effect of large scale structure on the stellar and gas content of galaxies in the high-redshift Universe.

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 10906

The Fundamental Plane of Massive Gas-Rich Mergers: II. The QUEST QSOs

We propose deep NICMOS H-band imaging of a carefully selected sample of 23 local QSOs. This program is the last critical element of a comprehensive investigation of the most luminous mergers in the nearby universe, the ultraluminous infrared galaxies {ULIRGs} and the quasars. This effort is called QUEST: Quasar / ULIRG Evolutionary STudy. The high-resolution HST images of the QUEST QSOs will complement an identical set of images on the ULIRG sample obtained during Cycle 12, an extensive set of ground-based data that include long-slit NIR spectra from a Large VLT Program, and a large set of mid-infrared spectra from a Cycle 1 medium-size program with Spitzer. This unique dataset will allow us to derive with unprecedented precision structual, kinematic, and activity parameters for a large unbiased sample of objects spanning the entire ULIRG/QSO luminosity function. These data will refine the fundamental plane of massive gas-rich mergers and enable us to answer the following quesitons: {1} Do ultraluminous mergers form elliptical galaxies, and in particular, giant ellipticals? {2} Do ULIRGs evolve into optical bright QSOs? The results from this detailed study of massive mergers in the local universe will be relevant to understanding the basic physical processes involved in creating massive early-type host on the one hand, and growing/feeding embedded massive black holes on the other, in major galaxy mergers. This is an important question since 50% of cosmic star formation at high-z and most of the big BHs appear to be formed in this process.

NIC2, ACS/WFC 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 10861

An ACS Treasury Survey of the Coma cluster of galaxies

We propose to use the unique spatial resolution of HST and ACS to construct a Treasury imaging survey of the core and infall region of the richest local cluster, Coma. We will observe samples of thousands of galaxies down to magnitude B=27.3 with the aim of studying in detail the dwarf galaxy population which, according to hierarchical models of galaxy formation, are the earliest galaxies to form in the universe. Our initial scientific objectives are: 1} A study of the structure of the dwarf galaxies, including scaling laws, nuclear structure and morphology, to compare with hierarchical and evolutionary models of their formation. 2} A study of the stellar populations from colors and color gradients, and how the internal chemical evolution of galaxies is affected by interaction with the cluster gaseous and galaxy environment. 3} To determine the effect of the cluster environment upon morphological features, disks, bulges and bars, by comparing these structure in the Coma sample with field galaxy samples. 4} Identification of dwarf galaxy samples for further study with the new generation of multi-object and integral-field spectrographs on 8-10 metre class telescopes such as Keck, Subaru, Gemini, and GTC. This is the first such survey of a nearby rich cluster. It will provide a key database for studies of galaxy formation and evolution, and a very needed reference for comparison with similar galaxy surveys both in lower density environments in the nearby universe, and in high density environments at high redshifts.

NIC3/ACS/WFC 10404

The Nature of Protocluster Galaxies at z=2.16: Morphology-Density and Color-Magnitude Relations

To establish the epoch when galaxy environment manifests itself as a large-scale evolutionary process, we propose to extend the study of galaxy colors and morphologies to a protocluster at z=2.16. Here the universe is only 3 Gyrs old and significant differences are expected between scenarios favoring a morphology-radius relation over a morphology-density relation. In addition, because the fractional age differences among cluster galaxies are larger, study of the color- magnitude relation provides considerable leverage for determining the epoch of early-type galaxy formation. To facilitate direct comparison to studies at lower redshift, one must probe the same rest-frame wavelengths with high photometric accuracy and at similar physical scales. Its near-infrared photometric stability {low, constant background} and ability to image large areas of sky at high angular-resolution {compared to adaptive optics} makes HST/NICMOS ideal for this program. Six pointings of NICMOS camera 3 will result in rest-frame optical, high resolution images of 16 confirmed protocluster members, and an additional 60 candidate protocluster members including 29 EROs. These galaxies were selected with a variety of techniques and span a range of projected radii within the protocluster. The proposed observations constitute a unique opportunity to extend the study of galaxies in overdense regions to an early time in cosmic history.

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.


Cycle 15 Focus Monitor

The focus of HST is measured primarily with ACS/HRC over full CVZ orbits to obtain accurate mean focus values via a well sampled breathing curve. Coma and astigmatism are also determined from the same data in order to further understand orbital effects on image quality and optical alignments. To monitor the stability of ACS to WFPC2 relative focii, we’ve carried over from previous focus monitor programs parallel observations taken with the two cameras at suitable orientations of previously observed targets, and interspersed them with the HRC CVZ visits.


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

HSTARS: (None)



                          SCHEDULED      SUCCESSFUL
FGS GSacq               10                     10
REacq               04                      04 

OBAD with Maneuver  27                      27


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