Status Report

NASA Hubble Space Telescope Daily Report #4210

By SpaceRef Editor
October 2, 2006
Filed under , ,
NASA Hubble Space Telescope Daily Report #4210


– Continuing to collect World Class Science

PERIOD COVERED: UT September 29,30, October 01, 2006 (DOY 272,273,274)


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.

NIC1 11001

Fallback Debris Disks Around Neutron Stars

Our Spitzer/IRAC discovery of a dusty debris disk around the young neutron star 4U 0142+61 is the first detection of a fallback disk around a neutron star. Fallback, the notion that some material from a supernova explosion could remain bound to the compact remnant, is a general prediction of core?collapse supernova models, yet until now there were few if any meaningful observational constraints on the size {or existence} of such disks. Here we propose to test the ubiquity of such disks with deep IRAC observations of two young neutron stars, each a representative of a different class of object {a rotation?powered pulsar and a radio?quiet neutron star in a supernova remnant}. We will examine whether fallback disks are common to all neutron stars or depend on the factors that separate these classes. Our proposed observations will pave the way for future surveys and in? depth investigations of individual objects.

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.

NIC3 10894

Probing the Birth of Super Star Clusters with NICMOS

The formation of “super star clusters” represents an extreme mode of star formation in the local universe. Star clusters with radii < 5pc and masses exceeding 10^4 solar masses are now known to be common in starbursts. These clusters are amazingly densely packed with massive stars, and can have a violent impact on their host galaxies and the surrounding IGM. The effects of massive star clusters perhaps were even more important in the earlier universe, when galaxy mergers and starbursts were common, and the formation of massive globular clusters was ubiquitous. However, our knowledge of the formation and early evolution of such massive clusters remains poorly understood, and observations have only begun to probe these stages. The near-IR fluxes and colors of natal clusters change dramatically in their early stages of evolution, providing important diagnostics. We will use NICMOS to explore the early evolution of massive star clusters through observations of a sample of nearby starburst galaxies containing the recently discovered ultra-young massive star clusters. First identified as compact optically- thick free-free radio sources, these natal clusters are still embedded in their birth material and obscured at optical wavelengths. Sensitive, high-resolution observations in the near-IR are critical for investigating the properties of these clusters as they evolve from being completely obscured by their natal clouds to fully emerged and optically visible. NICMOS F160W, F205W, F187N, and F190N {roughly H, K, and Pa-alpha} images will allow us to determine their ages, extinctions, ionizing fluxes, embedded stellar masses, and the morphological relationship between radio, mid-IR, and optically visible clusters. These results will ultimately provide insight into the earliest stages of super star cluster evolution and the properties of massive star formation throughout the universe.

NIC1 10879

A search for planetary-mass companions to the nearest L dwarfs – completing the survey

We propose to extend the most sensitive survey yet undertaken for very low-mass companions to ultracool dwarfs. We will use NICMOS to complete imaging of an all-sky sample of 87 L dwarfs in 80 systems within 20 parsecs of the Sun. The combination of infrared imaging and proximity allows us to search for companions with mass ratios q>0.25 at separations exceeding ~3 AU, while probing companions with q>0.5 at ~1.5 AU separation. This resolution is crucial, since no ultracool binaries are known in the field with separations exceeding 15 AU. Fifty L dwarfs from the 20-parsec sample have high-resolution imaging, primarily through our Cycle 13 HST proposal which identified six new binaries, including an L/T system. Here, we propose to target the remaining 30 dwarfs

WFPC2 10822

CIII] Imagery of Planetary Nebulae

We propose to image five planetary nebulae {PNe} with the F185W filter of WFPC2 in order to study the spatial distribution of the ultraviolet C III] 1909 Angstrom line relative to [O III] 5007 Angstrom and other optical lines. This program follows a Cycle 12 SNAP program {GO 9740} of WFPC2 F185W imaging of PNe and H II regions which validated the feasibility of obtaining images of bright PNe in C III] through careful continuum subtraction and calibrations based on archival IUE SWP and LWP/R spectra. However, in the SNAP program only short {10 minute} exposures of four PNe were taken; we now propose much longer exposures {60-72 minutes} to obtain the desired signal-to-noise to develop high quality C++ ionization maps for comparison with O++ and other ions via photoionization modeling. The five PNe chosen: NGC 2392, NGC 3242, NGC 6543, NGC 6720, and NGC 7662 were selected on the basis of their high surface brightness, extensive UV spectra available from IUE and HST, and numerous WFPC2 images in the archives in other emission lines. We expect the results of this study to impact the utility and accuracy of using the C III] 1909 lines compared to [O III] 5007 for C/O abundance derivations in PNe and H II regions.

NIC2 10808

Morphologies of spectroscopically-confirmed “red and dead” galaxies at z~2.5

Using a combination of wide-field near-infrared imaging and very deep follow-up near-infrared spectroscopy we have identified a population of massive “red and dead” galaxies at z~2.5. The galaxies lack emission lines and have strong Balmer/4000 Angstrom breaks, demonstrating directly that they have evolved stellar populations. These objects are very likely progenitors of massive ellipticals today and may be descendants of the first generation of galaxies. We propose to image 10 of these objects with the NIC2 camera to determine their morphologies. The goals are to 1} determine whether they have the sizes of present-day early-types or are more compact, as predicted by models, 2} determine the morphology, using visual classification and quantitative methods, and 3} constrain the evolution of the Kormendy relation from z~2.5 to the present. These observations will show whether the oldest and most massive galaxies at z~2.5 were already fully formed or still in the process of assembly.

FGS 10613

Calibrating the Mass-Luminosity Relation at the End of the Main Sequence

We propose to use HST-FGS1R to calibrate the mass-luminosity relation {MLR} for stars less massive than 0.2 Msun, with special emphasis on objects near the stellar/brown dwarf border. Our goals are to determine M_V values to 0.05 magnitude, masses to 5 than double the number of objects with masses determined to be less than 0.20 Msun. This program uses the combination of HST-FGS3/FGS1R at optical wavelengths and ground-based infrared interferometry to examine nearby, subarcsecond binary systems. The high precision measurements with HST-FGS3/FGS1R {to 1 mas in the separations} for these faint targets {V = 10–15} simply cannot be equaled by any ground based technique. As a result of these measurements, we are deriving high quality luminosities and masses for the components in the observed systems, and characterizing their spectral energy distributions from 0.5 to 2.2 Mum. Several of the objects included have M < 0.1 Msun, placing them at the very end of the stellar main sequence. Three of the targets are brown dwarf candidates, including the current low mass record holder, GJ 1245C, with a mass of 0.062 +/- 0.004 Msun. The payoff of this proposal is high because all 10 of the systems selected have already been resolved with HST- FGS3/FGS1R during Cycles 5--10 and contain most of the reddest objects for which masses can be determined.


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


10451 – Reacq (2,1,1) failed due to scan steps limit exceeded:

At AOS 272/14:52:39, telemetry showed the Reacq scheduled at 14:19:59 failed to scan steps limit exceeded. PCS mode was M2G, Sub mode M2DAttHld. (RGA Hold). OBAD @ 14:07:09 was during LOS. OBAD @ 14:15:03 showed errors of V1= 8.09, V2= -1.09, V3= 3.83, RSS= 9.02.

10452 – REacq (2,1,1) failed to RGA hold due to Stop flag on FGS 2:

Upon Acquisition 17:40:00 REacq (2,1,1) scheduled at 17:31:20 failed to RGA hold due to stop flag for FGS 2. QF2STOPF and QSTOP were the only mnemonics out of limits. OBAD @ 17:19:04; V1= -32.26, V2= -58.99, V3= -15.75, RSS= 69.09. OBAD @ 17:26:59; V1= 6.52, V2= 3.13, V3= -7.53, RSS= 10.44.

10453 – REAcq (2,1,1) failed to RGA control due to Search Radius Limit Exceeded on FGS 1:

At AOS @ 273/07:31:08 REAcq (2,1,1)scheduled from 273/06:54:11-07:01:38 was observed to have failed due to search radius limit exceeded on FGS 1. Received 486 ESB’s “1805” (x5)FHST moving target detected and “a05” Exceeded_SRL. OBAD #1 not seen due to LOS. OBAD #2: V1 -7.05, V2 -5.19, V3 4.80, RSS 9.99 OBAD MAP: V1, -56.96, V2 151.57, V3 -38.61, RSS 166.46


17936-2 – ACS HRC Relay Test

17937-1 – Recover ACS from Suspend to Operate (WFC CCD only)


                          SCHEDULED      SUCCESSFUL 
FGS GSacq                15                     15 
FGS REacq                19                     16 
OBAD with Maneuver   68                     68 


Flash Report

At 273/12:50 OPS Request 17937 was executed successfully to recover ACS from Suspend Mode to Operate Mode (WFC only) to allow for science intercept on Sunday evening with the start of SMS SA275Q02.

During the recovery process, the HRC Amp A Summing Wells (“JHSWALO”) unexpectedly flagged out-of-limits low to -7.03 V and HRC Amp C Summing Wells (“JHSWCLO”) did not flag out-of-limits low to -7.03 V as expected. After reviewing data, SI SE contacted STScI, 442 and Ball engineers who concurred that it acceptable to leave ACS in the current “operate” state and proceed with ACS WFC science operations in the 2006/275 SMS. Ball Engineers are continuing the investigation and will contact the SISE with any new information.

ACS Day 275 science SMS intercept

ACS successfully intercepted the SMS at 275/00:31 with a WFC Full Frame Bias Exposure and Readout. This image and the next five ACS WFC images are scheduled for playback off the SSR1 at 275/07:26.

SpaceRef staff editor.