Status Report

NASA Hubble Space Telescope Daily Status Report #4251

By SpaceRef Editor
December 5, 2006
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NASA Hubble Space Telescope Daily Status Report #4251


– Continuing to collect World Class Science

PERIOD COVERED: UT DECEMBER 01,02,03, 2006 (DOY 335,336,337)


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.

ACS/HRC 11047

ACS CCD Flash Calibration

This activity provides a set of CCD FLASH exposure reference images for each current level/shutter-side/detector combination, for the pair of FLASH LEDs on the instrument side currently in use. It also tests the short-term repeatability at the shortest FLASH exposure times that are expected to be used {1.0 sec}.

ACS/HRC 11041

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. For cycle 15 the program will cover 18 months 12.1.06->05.31.08 and it has been divied into three different proposal each covering six months. The three poroposals are 11041-11042-11043.

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.

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.

ACS/WFC 10882

Emission Line Snapshots of 3CR Radio Galaxies

Radio galaxies are an important class of extragalactic objects: they are one of the most energetic astrophysical phenomena and they provide an exceptional probe of the evolving Universe, lying typically in high density regions but well-represented across a wide redshift range. In earlier Cycles we carried out extensive HST observations of the 3CR sources in order to acquire a complete and quantitative inventory of the structure, contents and evolution of these important objects. We discovered new optical jets, dust lanes, and revealed point-like nuclei whose properties support AGN unified schemes. Here, we propose to obtain ACS emission line images at low and high excitation of 3CR sources with z<0.3, both low- and classical high- power radio galaxies, as a major enhancement to an already superb dataset. We aim to probe fundamental relationships between warm optical line-emitting gas, radio source structure {jets and lobes} and X-ray coronal halos. We will combine our existing UV images with new emission- line images to establish quantitative star formation characteristics and their relation to dust and merging, and with emission-line excitation maps, test theories on ionization beam patterns and luminosities from active nuclei. We will seek jet induced star formation and knowing optical emission-line physics, investigate quantitative jet physics. The nuclear emission line properties of the galaxies will themselves be established and used as ingredients in continuing tests of unified AGN theories. The resulting database will be an incredibly valuable resource to the astronomical community for years to come.

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.

ACS/WFC 10521

ACS Imaging of a Unique Spitzer Field: Morphology of mid-IR Variable Sources

We propose to observe the IRAC Dark Field, an extragalactic field 15 arcminutes in diameter near the north ecliptic pole, using 50 orbits of ACS imaging at I-band. This field is extraordinarily deep and is uniquely suited to detecting variable objects in the mid-infrared. The high spatial resolution ACS imaging will be used to derive morphological information about the galaxies in the field, which will then be correlated with mid-infrared variable objects {specifically AGN and supernovae} we have discovered. This field is the dark current calibration target for the Spitzer Space Telescope, the infrared counterpart to HST. Because the field is observed frequently as part of routine operations, it is now similar in size and depth to the infrared component of the GOODS program, and is confusion-limited in the mid-infrared. More importantly, due to the periodicity of the observations, the Spitzer observations are sensitive to variability on week timescales, ultimately spanning a baseline of five years, and are the only mid-infrared dataset that will ever have this capability at this depth. By complementing our wide range of lower resolution imaging at optical and infrared wavelengths, we hope to exploit one of HST’s most unique capabilities – unparalleled spatial resolution in the optical. While our specific interest lies in analysis of variable sources, we will request no proprietary period on the ACS data so that it may be used by the community to complement the publicly available Spitzer data.

ACS/HRC 10508

Orbits, Masses, and Densities of Three Transneptunian Binaries

The subset of transneptunian objects {TNOs} having natural satellites offers unique opportunities for physical studies of these distant relics from the outer parts of the protoplanetary nebula. HST/ACS is ideally suited to determining orbits of TNO satellites, resulting in the system masses. In conjunction with thermal emission observations by Spitzer, which provides sizes, we can determine the densities of TNOs. Densities offer a powerful window into their bulk compositions and interior structures.


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


10536 – REACQ(2,3,2) failed to RGA control REACQ(2,3,2) at 335:21:20:15 failed to RGA control during LOS period. Upon acquisition of signal at 21:44:00 vehicle was in gyro control with QF3STOPF and QSTOP flags set. No other flags were seen. Two 1805 ESB messages (T2G Moving Target Detected) occurred while vehicle was LOS. Primary GSACQ(2,3,2) at 19:45:15 was successful.

10537 – ACS 935 SEMAPHORE_TIMEOUT At 337/09:39:54 we received a ACS 935 status buffer message P=35 T=58833. This is a routine status buffer message. This is Semaphone_Timeout. This results when the take data flag goes down during CCD Post-Flash or a Filter wheel,Fold Mechanism, or Calibration door move.

10538 – GSAcq(2,3,2) failed to RGA control @337/1714z At AOS (337/17:13:52) GSAcq (2,3,2) scheduled 337/16:32:43-16:39:59 was observed to have failed to RGA control. QSTOP flag was received on FGS 2, no other flags noted. No 486 ESB messages noted at AOS. OBAD #1: data currently unavailable due to LOS. OBAD #2: V1 -2.04, V2 -6.24, V3 -1.56, RSS 6.75 OBAD Map: not scheduled.



                         SCHEDULED      SUCCESSFUL
FGS GSacq               21                     20
FGS REacq               24                     24
OBAD with Maneuver  90                     90


SpaceRef staff editor.