Status Report

NASA Hubble Space Telescope Daily Report #3992

By SpaceRef Editor
November 21, 2005
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NASA Hubble Space Telescope Daily Report #3992

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science


PERIOD COVERED: UT November 18, 19, 20, 2005 (DOY 322, 323, 324)



NICMOS Post-SAA calibration – CR Persistence Part 1.

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.

ACS/WFC 10740

Absolute Photometric & Spectrophometric Calibration

This program has several goals: 1.}Verify repeatability of the ACS instrumentation on a single bright star to +/-0.2%. 2.}Determine any shift in the filter bandpasses since the preflight lab measurements. 3.}Determine the relative magnitude of the 3 primary WD calibrators to 0.1%. 4.}Refine the sensitivity calibration of the CCD prism and grisms at field center and determine the repeatability accuracy of this calibration. 5.}Determine the level of variability of the three HST red standard stars: VB-8 {M7}, 2M0038+18 {L3.5} and 2M0559-14 {T5}, and also measure their short wavelength {<7000A} fluxes. 6.}Cross calibrate with a faint STIS and NICMOS standard WD and solar analog star.


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 10635

Galaxy Transformation as probed by Morphology and Velocity Fields of Distant Cluster Galaxies

We seek to obtain ACS imaging of four distant {0.3

ACS/WFC 10634

White Dwarf Cooling Physics: Calibrating the Clock

We know approximate ages for the Galactic disk from white dwarf cooling theory applied to local white dwarfs and for the Galactic halo from main sequence stellar evolutionary theory applied to star clusters. However, the two chronometers are not cross-calibrated to the same absolute scale; our observations will perform this cross-calibration and improve the precision of both chronometers. We propose to use HST/ACS photometry of white dwarfs in five moderately old open cluster {0.6-2.2 Gyr}, along with all available up-to-date white dwarf interior and atmosphere models and a powerful new statistical approach, to compare main sequence evolutionary theory and white dwarf cooling theory. This comparison will be done in such a manner as to test white dwarf crystallization and carbon/oxygen phase separation, as well as main sequence models in the range where they are sensitive to the degree of core overshooting and where PP burning transitions to CNO burning. This confrontation is essential before we can accurately and precisely apply white dwarf cosmochronometry to the disk and halo field populations and to globular clusters. Past support by HST for white dwarf ages in globular clusters {123 orbits for M4 and a similarly large scheduled campaign for NGC 6397} will only be fully levereged by ensuring that both stellar chronometers are calibrated to the same age scale. Only then can white dwarf chronometers live up to their potential as fundamental, independent, and new age estimators for the Galaxy.

ACS/WFC 10626

A Snapshot Survey of Brightest Cluster Galaxies and Strong Lensing to z = 0.9

We propose an ACS/WFC snapshot survey of the cores of 150 rich galaxy clusters at 0.3 < z < 0.9 from the Red Sequence Cluster Survey {RCS}. An examination of the galaxian light in the brightest cluster galaxies, coupled with a statistical analysis of the strong-lensing properties of the sample, will allow us to contrain the evolution of both the baryonic and dark mass in cluster cores, over an unprecedented redshift range and sample size. In detail, we will use the high- resolution ACS images to measure the metric {10 kpc/h} luminosity and morphological disturbances around the brightest clusters galaxies, in order to calibrate their accretion history in comparison to recent detailed simulations of structure formation in cluster cores. These images will also yield a well-defined sample of arcs formed by strong lensing by these clusters; the frequency and detailed distribution {size, multiplicity, redshifts} of these strong lens systems sets strong constraints on the total mass content {and its structure} in the centers of the clusters. These data will also be invaluable in the study of the morphological evolution and properties of cluster galaxies over a significant redshift range. These analyses will be supported by extensive ongoing optical and near-infrared imaging, and optical spectroscopy at Magellan, VLT and Gemini telescope, as well as host of smaller facilities.

FGS 10610

Astrometric Masses of Extrasolar Planets and Brown Dwarfs

We propose observations with HST/FGS to estimate the astrometric elements {perturbation orbit semi-major axis and inclination} of extra-solar planets orbiting six stars. These companions were originally detected by radial velocity techniques. We have demonstrated that FGS astrometry of even a short segment of reflex motion, when combined with extensive radial velocity information, can yield useful inclination information {McArthur et al. 2004}, allowing us to determine companion masses. Extrasolar planet masses assist in two ongoing research frontiers. First, they provide useful boundary conditions for models of planetary formation and evolution of planetary systems. Second, knowing that a star in fact has a plantary mass companion, increases the value of that system to future extrasolar planet observation missions such as SIM PlanetQuest, TPF, and GAIA.

ACS/WFC 10592

An ACS Survey of a Complete Sample of Luminous Infrared Galaxies in the Local Universe

At luminosities above 10^11.4 L_sun, the space density of far-infrared selected galaxies exceeds that of optically selected galaxies. These `luminous infrared galaxies’ {LIRGs} are primarily interacting or merging disk galaxies undergoing enhanced star formation and Active Galactic Nuclei {AGN} activity, possibly triggered as the objects transform into massive S0 and elliptical merger remnants. We propose ACS/WFC imaging of a complete sample of 88 L_IR > 10^11.4 L_sun luminous infrared galaxies in the IRAS Revised Bright Galaxy Sample {RBGS: i.e., 60 micron flux density > 5.24 Jy}. This sample is ideal not only in its completeness and sample size, but also in the proximity and brightness of the galaxies. The superb sensitivity, resolution, and field of view of ACS/WFC on HST enables a unique opportunity to study the detailed structure of galaxies that sample all stages of the merger process. Imaging will be done with the F439W and F814W filters {B and I-band} to examine as a function of both luminosity and merger state {i} the evidence at optical wavelengths of star formation and AGN activity and the manner in which instabilities {bars and bridges} in the galaxies may funnel material to these active regions, {ii} the relationship between star formation and AGN activity, and {iii} the structural properties {AGN, bulge, and disk components} and fundamental parameters {effective radius and surface brightness} of LIRGs and their similarity with putative evolutionary byproducts {elliptical, S0 and classical AGN host galaxies}. This HST survey will also bridge the wavelength gap between a Spitzer imaging survey {covering seven bands in the 3.6-160 micron range} and a GALEX UV imaging survey of these galaxies, but will resolve complexes of star clusters and multiple nuclei at resolutions well beyond the capabilities of either Spitzer or GALEX. The combined datasets will result in the most comprehensive multiwavelength study of interacting and merging galaxies to date.

ACS/WFC 10579

ULX counterparts: the key to finding intermediate-mass black holes

The origin and formation mechanism for supermassive black holes {SMBHs} found in the centres of most, if not all, galaxies remains one of the outstanding questions in astrophysics. Most scenarios involve the presence of massive black holes in the early universe, formed by the collapse of primordial Population III stars. It is predicted that a relic of this population could still be present in galactic halos in the current epoch, possessing masses from a few hundred times solar mass upwards. However, to date no CONCLUSIVE evidence for such a class of “intermediate-mass” black holes has been found. The most likely current candidates are the ultraluminous X-ray sources {ULXs}, which show tantalising evidence for IMBHs {e.g. the extreme X-ray luminosities and low disk temperatures expected from accreting IMBHs}. We propose to address this issue by identifying optical counterparts for six of the nearest ULXs. We will use this programme as a pathfinder for future radial velocity measurements, which will allow the orbital parameters and hence the first undisputed mass constraints for these systems to be determined.

ACS/HRC 10556

Neutral Gas at Redshift z=0.5

Damped Lyman-alpha systems {DLAs} are used to track the bulk of the neutral hydrogen gas in the Universe. Prior to HST UV spectroscopy, they could only be studied from the ground at redshifts z>1.65. However, HST has now permitted us to discover 41 DLAs at z<1.65 in our previous surveys. Followup studies of these systems are providing a wealth of information about the evolution of the neutral gas phase component of the Universe. But one problem is that these 41 low-redshift systems are spread over a wide range of redshifts spanning nearly 70% of the age of the Universe. Consequently, past surveys for low-redshift DLAs have not been able to offer very good precision in any small redshift regime. Here we propose an ACS-HRC- PR200L spectroscopic survey in the redshift interval z=[0.37, 0.7] which we estimate will permit us to discover another 41 DLAs. This will not only allow us to double the number of low-redshift DLAs, but it will also provide a relatively high-precision regime in the low-redshift Universe that can be used to anchor evolutionary studies. Fortunately DLAs have high absorption equivalent width, so ACS-HRC-PR200L has high-enough resoultion to perform this proposed MgII-selected DLA survey.

ACS/HRC 10549

SAINTS – Supernova 1987A INTensive Survey

SAINTS is a program to observe SN 1987A, the brightest supernova in 384 years, as it morphs into the youngest supernova remnant at age 18. HST is the unique and perfect tool for spatially- resolved observations of the many physical components of SN 1987A. A violent encounter is underway between the fastest-moving debris and the circumstellar ring, exciting hotspots seen with HST that are suddenly lighting up. The optical and X-ray flux from the ring are both rising rapidly: HST and Chandra observations taken together are needed to understand the physics of these shocked regions. In Cycle14, the hotspots may fuse as the shock fully enters the ring. Photons from these shocks may excite previously hidden gas outside the ring, revealing the true extent of the mass loss that preceded the explosion. The inner debris of the explosion itself, still excited by radioactive isotopes produced in the explosion, is now well resolved by ACS and seen to be aspherical, providing direct clues to the mechanism of the explosion. Our search for a compact remnant is beginning to eliminate some theoretical possibilities and we have the opportunity in Cycle 14 to place much more stringent limits with NICMOS. Many questions about SN 1987A remain unanswered. How did the enigmatic three rings form in the late stages of Sanduleak -69 202? Precisely what took place in the center during the core collapse and bounce? Is a black hole or a neutron star left behind in the debris? SAINTS has been a continuous program since HST was launched– we propose to extend this rich and deep data set for present use and future reference to answer these central questions in the science of supernovae.

NIC2 10527

Imaging Scattered Light from Debris Disks Discovered by the Spitzer Space Telescope Around 20 Sun-like Stars

We propose to use the high contrast capability of the NICMOS coronagraph to image a sample of newly discovered circumstellar disks associated with sun-like stars. These systems were identified by their strong thermal infrared emission with the Spitzer Space Telescope as part of the Spitzer Legacy Science program titled, “The Formation and Evolution of Planetary Systems {FEPS}.” Modelling of the thermal excess emission in the form of spectral energy distributions alone cannot distinguish between narrowly confined high opacity disks and broadly distributed, low opacity disks. However, our proposed NICMOS observations can, by imaging the light scattered from this material. Even non- detections will place severe constraints on the disk geometry, ruling out models with high optical depth. Unlike previous disk imaging programs, our program contains a well defined sample of solar mass stars covering a range of ages from ~10Myrs to a few Gyrs, allowing us to study the evolution of disks from primordial to debris for the first time. These results will greatly improve our understanding of debris disks around Sun- like stars at stellar ages nearly 10x older than any previous investigation. Thus we will have fit a crucial piece into the puzzle concerning the formation and evolution of our own solar system.

ACS/HRC 10525

Characterizing the Near-UV Environment of M Dwarfs: Implications for Extrasolar Planetary Searches and Astrobiology

We propose SNAP observations with the ACS HRC PR200L prism, designed to measure the near ultraviolet emission in a sample of 107 nearby M dwarfs. The sample spans the mass range from 0.1 – 0.6 solar masses {temperature range 2200K – 4000K} where the UV energy distributions vary widely between active and inactive stars. The strength and distribution of this UV emission can have critical consequences for the atmospheres of attendant planets. Our proposed observations will provide desperately needed constraints on models of the habitability zone and the atmospheres of possible terrestrial planets orbiting M dwarf hosts, and will be used to sharpen TPF target selection. In addition, the NUV data will be used in conjunction with existing optical, FUV and X-ray data to constrain a new generation of M dwarf atmospheric models, and to explore unanswered questions regarding the dynamo generation and magnetic heating in these low-mass stars.

ACS/WFC 10522

Calibrating Star Formation: The Link between Feedback and Galaxy Evolution

Stellar feedback – the return of mass and energy from star formation to the interstellar medium – is one of the primary engines of galaxy evolution. Yet, the theoretical foundation of mechanical feedback is, to date, unconstrained by observations. We propose to investigate this fundamental aspect of star formation on a sample of two local actively star-forming galaxies, NGC4449, and Holmberg II. The two galaxies have been selected to occupy an unexplored, yet crucial for quantifying mechanical feedback, niche in the two-parameter space of star formation intensity and galaxy mass. ACS/WFC and WFPC2 narrow-band observations in the light of H-beta, [OIII], H-alpha, and [NII] will be obtained for both galaxies, in order to: {1} discriminate the feedback- induced shock fronts from the photoionization regions; {2} map the shocks inside and around the starburst regions; and {3} measure the energy budget of the star-formation-produced shocks. These observations, complemented by existing data, will yield: {1} the efficiency of the feedback, i.e. the fraction of the star formation’s mechanical energy that is transported out of the starburst volume rather than confined or radiated away; {2} the dependence of this efficiency on the two fundamental parameters of star formation intensity and stellar mass. The high angular resolution of HST is crucial for separating the spatially narrow shock fronts {~5 pc, ~0.25″ at 4 Mpc} from the more extended photoionization fronts. The legacy from this project will be the most complete quantitative measurement of the energetics associated with feedback processes. We will secure the first milestone for placing feedback mechanisms on a solid physical ground, and for understanding quantitatively their role on the energetics, structure, and star formation history of galaxies at all redshifts.


The Late Formation of Satellite Galaxies

Tiny isolated HII regions have been discovered up to 30 kpc from the closest galaxy in the NOAO Survey for Ionization in Neutral Gas Galaxies {SINGG}. These halo HII regions can be ionized by only a few OB stars and seem to be most commonly found in interacting systems. They may represent the beginning of the formation of satellite galaxies at low redshift and/or are the source of the numerous intracluster planetary nebula. The halo HII regions are a unique mode of star formation in a low density and low metallicity environment and high resolution HST images are required to identify their underlying stellar populations. Determining the stellar populations of these HII regions will establish whether in-situ star formation is a significant contributor to the stellar content and enrichment of galactic halos and intergalactic space. In particular, ACS/HRC observations are required for their resolution, UV sensitivity, and wide wavelength coverage, allowing young and intermediate age populations to be identified. Parallel ACS/WFC observations will explore the possibility of a further stellar population in the interactive debris. The results of this project have implications on the formation of satellite galaxies, the origin of Galactic halo B stars, IGM ionization and enrichment, and star formation principles.


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


10020 – OBAD Failed ID / REAcq (1,2,1) not attempted @ 322/12:20:47z OBAD1 scheduled @ 322/12:06:18 failed. At 12:08:02 recveived 486 ESB 1805(X2)(T2G Moving Target Detected) & 1902 (OBAD Failed ID). OBAD2 was successful and showed errors of: V1 -50.42, V2 2412.56, V3 -30.46, RSS 2413.28. REAcq (1,2,1) scheduled @ 12:20:47 was not attempted. Their were no indications of transitioning to M2G. MAP @ 12:28:07 showed errors of: V1=6.77, V2=9.76, V3=11.58, RSS=16.59.


17590-0 – Update Benchmark SOC, SOC1, SOC2, and Pressure Limits @ 322/1412z

17537-1 – Restore TMDIAG Slot 0 for VehConLaw.Integral Path Data @ 322/1415z

17591-0 – Full Memory Dump @ 322/1701z


                         SCHEDULED      SUCCESSFUL      FAILURE TIMES
FGS GSacq                23                    23
REacq                16                    15                 322/12:20:47 
(HSTAR #10020)
OBAD with Maneuver   78                     77                322/12:06:18 
(HSTAR #10020)



“Battery SOC Modifications”): On DOY 2005/322, Ops Request 17590-0 was successfully executed to update the benchmark SOC, SOC1, SOC2, and Pressure Limits. These updates were made because the six-battery benchmark SOC, SOC 1 and SOC 2 should be adjusted periodically to reflect changes in battery capacity. The Electrical Power Subsystem continues to perform as expected.

SpaceRef staff editor.