NASA Hubble Space Telescope Daily Report #4093

Status Report From: Space Telescope Science Institute
Posted: Monday, April 17, 2006


HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science


PERIOD COVERED: UT April 14,15,16, 2006 (DOY 104,105,106)



Quit winking: Jupiter opens its other eye

This week {March 6} a new red spot on Jupiter was announced, dubbed "Red Spot Jr.'' by the press. It appears to be White Oval BA, the remanant of the three White Ovals that merged during 1998-2000. The new spot is deep red like the Great Red Spot {GRS} rather than bright white as were the ovals. We believe that the color change of the oval from white to red is indicative of a temperature change, as predicted by one of us in a Nature paper in 2004. The goal of our proposed observations is to test our theory of jovian climate change through observations of dynamical features of Red Spot Jr. and its surroundings, which provide indirect measurements of changes in the temperature and stratification of the jovian weather layer.

ACS/WFC 10775

An ACS Survey of Galactic Globular Clusters

We propose to conduct an ACS/WFC imaging survey of Galactic globular clusters. We will construct the most extensive and deepest set of photometry and astrometry to-date for these systems reaching a main sequence mass of ~0.2 solar mass with S/N >= 10. We will combine these data with archival WFPC2 and STIS images to determine proper motions for the stars in our fields. The resultant cleaned cluster CMDs will allow us to study a variety of scientific questions. These include [but are not limited to] 1} the determination of cluster ages and distances 2} the construction of main sequence mass functions and the issue of mass segregation 3} the internal motions and dynamical evolution of globular clusters, and 4} absolute cluster motions, orbits, and the Milky Way gravitational potential. We anticipate that the unique resource provided by the proposed treasury archive will play a central role in the field of globular cluster studies for decades, with a stature comparable to that of the Hubble Deep Field for high redshift studies.


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 10736

ACS UV contamination monitor

The observations consist of imaging and spectroscopy with SBC and HRC of the cluster NGC 6681 in order to monitor the temporal evolution of the UV sensitivity of the SBC and the HRC. All UV modes except for SBC PR130L will be used.

S/C/NIC1 10724

NICMOS Focus Monitoring

The purpose of this proposal is to determine the best focus for all three NICMOS detectors. The program will be executed every ~6 weeks. Each execution will concern a single detector, except two occasions which will include NIC3. In total NIC1 and NIC2 will be monitored 4 times each during the current cycle, while NIC3 will only be monitored twice. The program starts with a focus sweep using only the NIC1 camera {visit 11}. The following observation is with the NIC2 camera {visit 12} after about 45 days. This pattern is repeated throughout the period except for Jan 1-8 and Jul 1-8 where also the NIC3 camera is used. In total this will result in 10 orbits. Notice that VISIT #1 #2 refers to visits for #1 sequential visit number for a given camera #2 camera in question visit 32 is therefore the third visit for camera 2. Some tweaking of dates and sources are necessary to ensure visibility under 2-gyro mode. These are the dates and targets for Cycel14: Visit 11: Oct 01-08 NIC1 NGC1850 Visit 12: Nov 15-22 NIC2 NGC3603 Visit 21: Jan 01-15 NIC1 NGC3603 Visit 13: Jan 01-15 NIC3 NGC3603 Visit 22: Feb 15-22 NIC2 NGC3603 Visit 31: Apr 01-15 NIC1 NGC1850 Visit 32: May 22-31 NIC2 NGC3603 Visit 41: Jun 15-22 NIC1 NGC1850 Visit 23: Jun 15-22 NIC3 NGC1850 Visit 42: Aug 07-22 NIC2 NGC3603

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 10588

The Host Galaxies of Post-Starburst Quasars

We propose to use ACS to conduct a snapshot imaging survey of post-starburst quasars now being discovered in signficant numbers by the Sloan Digital Sky Survey. Post-starburst quasars are broad-lined AGN that also possess Balmer jumps and high-n Balmer absorption lines indicative of luminous stellar populations on order of 100 Myr old. These objects, representing a few percent of the z < 0.5 quasar population, may be an evolutionary stage in the transition of ultraluminous infrared galaxies into normal quasars, or a type of galaxy interaction that triggers both star formation and nuclear activity. These sources may also illustrate how black hole mass/bulge mass correlations arise. Ground-based imaging of individual poststarburst quasars has revealed merger remnants, binary systems, and single point sources. Our ACS snapshots will enable us to determine morphologies and binary structure on sub-arcsecond scales {surely present in the sample}, as well as basic host galaxy properties. We will be looking for relationships among morphology, particularly separation of double nuclei, the starburst age, the quasar black hole mass and accretion rate, that will lead to an understanding of the triggering activity and mutual evolution. This project will bring quantitative data and statistics to the previously fuzzy and anecdotal topic of the "AGN-starburst connection" and help test the idea that post-starburst quasars are an early evolutionary stage of normal quasars.

ACS/WFC 10587

Measuring the Mass Dependence of Early-Type Galaxy Structure

We propose two-color ACS-WFC Snapshot observations of a sample of 118 candidate early- type gravitational lens galaxies. Our lens-candidate sample is selected to yield {in combination with earlier results} an approximately uniform final distribution of 40 early-type strong lenses across a wide range of masses, with velocity dispersions {a dynamical proxy for mass} ranging from 125 to 300 km/s. The proposed program will deliver the first significant sample of low-mass gravitational lenses. All of our candidates have known lens and source redshifts from Sloan Digital Sky Survey data, and all are bright enough to permit detailed photometric and stellar- dynamical observation. We will constrain the luminous and dark-matter mass profiles of confirmed lenses using lensed-image geometry and lens-galaxy structural/photometric measurements from HST imaging in combination with dynamical measurements from spatially resolved ground-based follow-up spectroscopy. Hence we will determine, in unprecedented detail, the dependence of early-type galaxy mass structure and mass-to-light ratio upon galaxy mass. These results will allow us to directly test theoretical predictions for halo concentration and star-formation efficiency as a function of mass and for the existence of a cuspy inner dark- matter component, and will illuminate the structural explanation behind the fundamental plane of early-type galaxies. The lens-candidate selection and confirmation strategy that we propose has been proven successful for high-mass galaxies by our Cycle 13 Snapshot program {10174}. The program that we propose here will produce a complementary and unprecedented lens sample spanning a wide range of lens-galaxy masses.

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/WFC 10550

The Nature of LSB galaxies revealed by their Globular Clusters

Low Surface Brightness {LSB} galaxies encompass many of the extremes in galaxy properties. Their understanding is essential to complete our picture of galaxy formation and evolution. Due to their historical under-representation on galaxy surveys, their importance to many areas of astronomy has only recently began to be realized. Globular clusters are superb tracers of the formation histories of galaxies and have been extensively used as such in high surface brightness galaxies. We propose to investigate the nature of massive LSB galaxies by studying their globular cluster systems. No globular cluster study has been reported for LSB galaxies to date. Yet, both the presence or absence of globular clusters set very strong constraints on the conditions prevailing during LSB galaxy formation and evolution. Both in dwarf and giant high surface brightness {HSB} galaxies, globular clusters are known to form as a constant fraction of baryonic mass. Their presence/absence immediately indicates similarities or discrepancies in the formation and evolution conditions of LSB and HSB galaxies. In particular, the presence/absence of metal-poor halo globular clusters infers similarities/differences in the halo formation and assembly processes of LSB vs. HSB galaxies, while the presence/absence of metal-rich globular clusters can be used to derive the occurrence and frequency of violent events {such as mergers} in the LSB galaxy assembly history. Two band imaging with ACS will allow us to identify the globular clusters {just resolved at the selected distance} and to determine their metallicity {potentially their rough age}. The composition of the systems will be compared to the extensive census built up on HSB galaxies. Our representative sample of six LSB galaxies {cz < 2700 km/s} are selected such, that a large system of globular clusters is expected. Globular clusters will constrain phases of LSB galaxy formation and evolution that can currently not be probed by other means. HST/ACS imaging is the only facility capable of studying the globular cluster systems of LSB galaxies given their distance and relative scarcity.

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.


Kuiper Belt Binaries: Probes of Early Solar System Evolution

Binaries in the Kuiper Belt are a scientific windfall: in them we have relatively fragile test particles which can be used as tracers of the early dynamical evolution of the outer Solar System. We propose a Snapshot program using the ACS/HRC that has a potential discovery efficiency an order of magnitude higher than the HST observations that have already discovered the majority of known transneptunian binaries. By more than doubling the number of observed objects in dynamically hot and cold subpopulations we will be able to answer, with statistical significance, the question of whether these groups differ in the abundance of binaries as a result of their particular dynamical paths into the Kuiper Belt. Today's Kuiper Belt bears the imprints of the final stages of giant-planet building and migration; binaries may offer some of the best preserved evidence of that long-ago era.

ACS/SBC 10507

High resolution imaging of Jupiter's diffuse auroral emissions inside and outside the main oval during solar

The analysis of HST-STIS FUV images has greatly and quickly advanced our knowledge of the magnetospheric mechanisms producing the auroral emissions on the giant planets. However, these studies were limited to the brightest emissions and very little has been said about the fainter emissions, mainly because of the lower S/N. We propose to image the faint auroral emissions on Jupiter which could not be observed with STIS. We will take full advantage of ACS/SBC's higher sensitivity to observe the diffuse auroral FUV emissions appearing poleward and directly equatorward of Jupiter's main auroral oval in the northern hemisphere. This proposal has the potential to reveal new magnetosphere-ionosphere coupling mechanisms especially those involving solar wind interactions with a giant planet.

ACS/HRC 10488

The Most Massive Galaxies in the Universe: Color-Gradients and Texture

We are proposing an HST snapshot survey of 40 objects with velocity dispersion larger than 350 km/s, selected from the Sloan Digital Sky Survey and confirmed to be single massive galaxies by the ACS-HRC i-band imaging obtained during Cycle 13. This sample of the most massive galaxies in the Universe is interesting because these objects potentially harbor the most massive black holes, and because their existence places strong constraints on galaxy formation models. These objects are unusual for another reason than their abnormally large velocity dispersions: they appear to be bluer than expected from extrapolation of the color-velocity dispersion relation of normal early-types to these large velocity dispersions. The bluer than expected colors indicate that the formation histories of these objects are likely to be rather different than for normal early-types. This difference is also expected to manifest as abnormal color-gradients. ACS-HRC imaging in one other band {i.e. the g-band} will allow us not simply to analyze color gradients in these objects but also to study their color texture and topology. This study will provide important information about the formation history of galaxies.


A Search for Debris Disks in the Coeval Beta Pictoris Moving Group

Resolved observations of debris disks present us with the opportunity of studying planetary evolution in other solar systems. We propose to search for debris disks in the Beta Pictoris moving group {8-20 Myrs, 10-50 pc away} , which provides a coeval sample of multiple spectral types, and it has already produced two magnificent resolved debris disks: AU Mic and Beta Pic. Such coeval sample will provide us with a snapshop of the crucial time in disk evolution in which the disk makes the transition from optically thick to optically thin, and it will be useful to study the stellar mass dependence of the disk evolution.

ACS/SBC 10125

Where is the Wind in 1H0707-495?

We propose three observations using the narrow-line Seyfert 1 galaxy 1H 0707-495 to be coordinated with already-approved deep exposures using FUSE. A previous HST observation of 1H 0707-495 revealed strongly blueshifted high-ionization lines, suggesting an origin in an outflowing wind. Detailed photoionization modeling reveals that the wind line fluxes and ratios are consistent with two solutions: a high-density, high-column solution, originating close to the central engine, and a low-density, low-column solution, located much further out. These two locations, interestingly, correspond to those predicted by two different physical models for winds in AGNs. We can differentiate between these models by observing emission line variability on two time scales, and examining relative variability of OVI obtained by FUSE and CIV and other lines obtained by HST. We will also look for profile variability, constrain velocity ionization stratification through a detailed study of the profiles, and investigate metallicity, which has been suggested to be high in NLS1s. This program, requiring only a modest amount of time, is expected to make significant contributions to our understanding of outflows in AGN, and the structure, origin and metallicity of the broad-line region.


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


10221 - REacq(2,1,1) resulted in finelock backup (2,0,2) @ 104/1206z The REacq(2,1,1) scheduled at 104/12:03:16 resulted in finelock backup (2,0,2). Only mnemonics QF1STOPF and QSTOP flagged out of limits at 12:06:54. There were no indication of scan step limit exceeded.

10222 - GSAcq (2,3,3) failed due to Scan Step Limit Exceeded on FGS-2 @ 105/2344z
At AOS (105/23:44:32) GSAcq (2,3,3) scheduled at 105/22:53:23-23:00:14 showed failed due to scan step limit exceeded on FGS-2.
OBAD #1: V1 1390.42, V2 3621.44, V3 1285.93, RSS 4086.77
OBAD #2: V1 0.61, V2 -4.01, V3 -8.94, RSS 9.81

10223 - GSAcq (2,1,2) results in Fine Lock Back-up @ 106/0128z At AOS (106/01:27:45), GSAcq 2,1,2 (scheduled @ 106/00:26:59-00:33:59) had resulted in FIne Lock Back-up 2,0,2 on FGS-2.
OBAD #1: V1 -280.61, V2 4962.27, V3 -432.94, RSS 4989.02
OBAD #2: V1 -11.97, V2 -17.76, V3 -1.12, RSS 21.45
OBAD MAP: V1 3.82, V2 -4.89, V3 -0.01, RSS 6.20

10224 - REAcq (2,1,1) results in Fine Lock Back-up @ 106/0204z
REAcq (2,1,1) scheduled at (106/02:00:26-02:07:26) resulted in Fine Lock Back-up on FGS-2. There were no OBADs prior to acquisition.

10225 - HST Entered Inertial Hold @ 107/0309z
HST entered inertial hold on day 107:03:09:57 after failing a bright earth/moon avoidance test. Neg. Acq. on TDE support at 107/0415z. Acquired 4K ENG data at 107/0424 after GCMRs.


17708-0 - Null genslews for proposal 10992 - slots 1, 2, 6, 12, and 13 @ 104/1506z
17709-0 - Lower VTFE Curves to K1L4 - 100mV (High Sun) @ 104/1615z
17695-2 - Monitor VehConLaw.Integral Path Data via TMDIAG Slot 0 (Generic OR) @ 104/1622z
17712-0 - Disable 1-MHz output @ 107/0612z
17713-0 - Transition NICMOS to SAA Operate @ 107/0739z
17715-0 - GEA's Turn On @ 107/0835z


                           SCHEDULED      SUCCESSFUL      FAILURE TIMES
FGS GSacq                25                      22                (HSTAR # 
FGS REacq                15                      15
OBAD with Maneuver   80                      72


VTFE Curve Adjustment

The initial adjustment of lowering the VTFE curves by 50mV to mitigate battery temperature increases during high sun-time did not result in enough of a decrease in temperatures. Therefore, as per the high sun-time contingency, EPS SEs lowered the VTFE curves on all the batteries by 50mV to K1L4-100mV via Ops Request 17709 on DOY 2006/104 at 16:16 GMT.


HST entered inertial hold on day 107:03:10:00.5 after failing a bright earth/moon avoidance test. All SIs are up in operate mode with no out-of-limit conditions.

// end //

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