Status Report

NASA Hubble Space Telescope Daily Report #4171

By SpaceRef Editor
August 7, 2006
Filed under , ,
NASA Hubble Space Telescope Daily Report #4171
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COMPLETED OPS REQUEST:

17878-0 – Genslew for proposal 10828- slot 5 @ 216/1513z

17879-0 – Genslew for proposal 10828- slot 6 @ 216/1514z

COMPLETED OPS NOTES: (None)

                          SCHEDULED      SUCCESSFUL 
FGS GSacq                28                      27 
FGS REacq                16                      16 
OBAD with Maneuver   88                      88 

SIGNIFICANT EVENTS:

Battery 1 Capacity Test Final Flash Report

At approximately 2006/216 16:55 GMT (12:55 pm local), Battery 1 was successfully commanded back on-line in FSW. The remaining commanding of the Battery 1 Reconditioning script was completed at approximately 2006/216 17:20 GMT (1:20 pm local).

EPS SEs monitored the system for 2 orbits after restoring EPS to a 6-battery FSW configuration and observed that the FSW SOC vs pressure-based SOC variance is ~24 AH. If this condition persists for the next 2 orbits with the delta greater than 15 AH, per the contingency plan, EPS SE will increase the SOC2 safemode limit by 5 AH (from 152 AH to 157 AH). Nominal system performance was observed for the rest of the EPS system. Battery temperatures are still cycling within nominal limits with battery 5 the warmest at 3.90 DegC.

HUBBLE SPACE TELESCOPE – Continuing to collect World Class Science

DAILY REPORT # 4171

PERIOD COVERED: UT August 4,5,6, 2006 (DOY 216,217,218)

OBSERVATIONS SCHEDULED

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/WFC 10911

Calibration of ACS F814W Surface Brightness Fluctuations

The surface brightness fluctuations {SBF} method has emerged as the primary distance indicator for mapping local large-scale structures {Virgo, Fornax}, as well as the velocity field out to nearly 15,000 km/s {z < 0.05}. This is because other precision distance indicators either lack the requisite depth {Cepheids, TRGB} or are too rare for adequate sampling {supernovae}, while more traditional methods {Tully-Fisher, fundamental plane} lack the necessary precision. The SBF method is now being used with great success in several major ACS Wide Field Camera programs. However, whereas the band of choice for the nearby structure studies has been F850LP, for the distant large-scale flow studies it is F814W because of its much greater throughput. As a result, the current calibration for the more distant studies is inadequate. We propose to establish the first systematic calibration of the SBF method in the important F814W ACS WFC bandpass. We will do this by measuring SBF in an optimized sample of galaxies in the nearby compact Fornax cluster. Given the large amount of effort and HST time being dedicated to F814W SBF measurements, it is imperative that we correct this outstanding calibration problem while time remains. For an extremely modest expenditure of orbits, we will remove a significant systematic error and vastly improve the overall accuracy of the ongoing ACS F814W SBF work. These data will also greatly enhance the legacy value of the HST archive for future SBF studies.

NIC2 10847

Coronagraphic Polarimetry of HST-Resolved Debris Disks

We propose to take full advantage of the recently commissioned coronagraphic polarimetry modes of ACS and NICMOS to obtain imaging polarimetry of circumstellar debris disks that were imaged previously by the HST coronagraphs, but without the polarizers. It is well established that stars form in gas-rich protostellar disks, and that the planets of our solar system formed from a circum-solar disk. However, the connection between the circumstellar disks that we observe around other stars and the processes of planet formation is still very uncertain. Mid-IR spectral studies have suggested that disk grains are growing in the environments of young stellar objects during the putative planet- formation epoch. Furthermore, structures revealed in well resolved images of circumstellar disks suggest gravitational influences on the disks from co-orbital bodies of planetary mass. Unfortunately, existing imaging data provides only rudimentary information abou the disk grains and their environments. Our proposed observations, which can be obtained only with HST, will enable us to quantitatively determine the sizes of the grains and optical depths as functions of their location within the disks {i.e., detailed tomography}. Armed with these well-determine physical and geometrical systemic parameters, we will develop a set of self-consistent models of disk structures to investigate possible interactions between unseen planets and the disks from which they formed. Our results will also calibrate models of the thermal emission from these disks, that will in turn enable us to infer the properties of other debris disks that cannot be spatially resolved with current or planned instruments and telescopes.

ACS/HRC 10844

Following Eta Carinae’s Change of State

Eta Carinae is now known to be undergoing some unusually rapid changes on a timescale of several years. They are probably essential for modeling the star’s long-term recovery from its Giant Eruption 160 years ago — the prototype “supernova impostor” event. Since high spatial resolution is needed to isolate the central star, and the present state will probably not recur in the future, it is important to obtain HST data during the next two years. We propose a cost-effective set of ACS observations with three goals: {1} to obtain a continuing record of the star’s rapid UV and visual brightening; {2} to lengthen the temporal baseline of ACS images enough to settle an important question concerning ejecta ages; and {3} to extend the record of morphological changes in the inner ejecta past the midpoint of eta Car’s 5.5-year cycle.

NIC3 10839

The NICMOS Polarimetric Calibration

Recently, it has been shown that NICMOS possesses an instrumental polarization at a level of 1.2%. This completely inhibits the data reduction in a number of previous GO programs, and hampers the ability of the instrument to perform high accuracy polarimetry. In all, 90 orbits of HST data are affected, with potentially many more in Cycle 15. We propose to obtain high signal to noise observations of three polarimetric standards at the cardinal roll angles of the NICMOS polarizers for both NIC1 and NIC2. These observations are designed to fully characterize the instrumental polarization in order for NICMOS to reach its full potential by enabling high accuracy polarimetry of sources with polarizations around 1%. The residual polarization will also be determined as a function of position and spectral energy distribution. Our group will rapidly turn around the required data products and produce reports and software for the accurate representation of the instrumental polarization. These items will be presented to STScI and for dissemination among the wider astronomical community.

ACS/WFC 10829

Secular Evolution at the End of the Hubble Sequence

The bulgeless disk galaxies at the end of the Hubble Sequence evolve at a glacial pace relative to their more violent, earlier-type cousins. The causes of their internal, or secular evolution are important because secular evolution represents the future fate of all galaxies in our accelerating Universe and is a key ingredient to understanding galaxy evolution in lower-density environments at present. The rate of secular evolution is largely determined by the stability of the cold ISM against collapse, star formation, and the buildup of a central bulge. Key diagnostics of the ISM’s stability are the presence of compact molecular clouds and narrow dust lanes. Surprisingly, edge-on, pure disk galaxies with circular velocities below 120 km/s do not appear to contain such dust lanes. We propose to obtain ACS/WFC F606W images of a well-selected sample of extremely late-type disk galaxies to measure the characteristic scale size of the cold ISM and determine if they possess the unstable, cold ISM necessary to drive secular evolution. Our sample has been carefully constructed to include disk galaxies above and below the critical circular velocity of 120 km/s where the dust properties of edge-on disks change so remarkably. We will then use surface brightness profiles to search for nuclear star clusters and pseudobulges, which are early indicators that secular evolution is at work, as well as measure the pitch angle of the dust lanes as a function of radius to estimate the central mass concentrations.

ACS/HRC 10800

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 to continue a Snapshot program using the ACS/HRC that has a demonstrated discovery potential an order of magnitude higher than the HST observations that have already discovered the majority of known transneptunian binaries. With this continuation we seek to reach the original goals of this project: to accumulate a sufficiently large sample in each of the distinct populations collected in the Kuiper Belt to be able to measure, with statistical significance, how the fraction of binaries varies as a function 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/HRC 10796

A SNAP Image of the Circumstellar Ejecta of AE And in M31

The “supernova impostor” or Luminous Blue Variable AE Andromedae in M31 has a spectrum that more closely resembles eta Car than any other known LBV, including the presence of anomalously strong and peculiar Fe II emission. An early FOC ultraviolet image of AE And showed a faint, fuzzy extension of the presumed stellar object. This may be nebulosity from an earlier eruption, or a very nearby UV-bright star. Possibly AE And is embedded in a bipolar nebula. In any case, 2-color ACS/HRC imaging will show the nature of this object. The presence of ejecta will be relevant to understanding the anomalous emission. If nebulous, the shape and extent of the ejecta can provide information on the wind geometry. An extended bipolar structure, similar to eta Car, would be especially interesting as it may be a clue to the mechanism of the more energetic giant eruptions.

ACS/HRC/WFC 10758

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.

NIC3 10728

Flats Stability

This calibration proposal is the Cycle 14 NICMOS flat field monitor program. A series of camera 1, 2, & 3 flat fields will be obtained to monitor the health of the cameras.

ACS/HRC 10623

HST Optical Snapshot Survey of Intermediate Redshift Ultraluminous Infrared Galaxies

Ultraluminous infrared galaxies {ULIGs} are commonly believed to be a transitory phase in the evolution of disk galaxy mergers into QSOs. However, a recently reported discrepancy between the morphological and structural properties of z < 0.13 ULIGs and z = 0.12-0.25 QSOs with M{V} < -23.5 has cast doubt on their evolutionary connection. We propose an ACS snapshot survey of a sample of 39 ULIGs with z = 0.35-1.0. These galaxies are the best suited for comparison with luminous z=0.12-0.25 QSOs because {1} they are at larger lookback times than local ULIGs, and thus are likely representative of the systems that evolve into lower redshift luminous QSOs, {2} they have luminosities comparable to luminous QSOs and, {3} they are selected in a manner that biases the sample towards harboring imbedded AGN, and thus are the most likely precursors to optical QSOs. High resolution HST ACS images will allow a determination of galaxy morphology and reveal the presence of bright AGN. The 2-D profile of each galaxy will be modeled using GALFIT, with the AGN comprising one component of the fit where applicable to better characterize the underlying galaxy. Fundamental parameters {effective radius and surface brightness, and F814W-band magnitude} of the underlying galaxy will thus be measured and compared with the host galaxies of the luminous QSO sample. This imaging campaign will consume a modest amount of HST time, but will provide for the first time a statistically significant view of ULIGs at look-back times of 30-65% the age of the universe, and sufficient resolution and sensitivity to conduct a meaningful comparison with z=0.12-0.25 QSOs, as well as with local {z < 0.3} IRAS-detected and distant {z > 2} SCUBA-detected ULIGs.

ACS/WFC 10546

The filaments of NGC1275

The spectacular H-0alpha filaments stretching over 100 kpc around the central galaxy in the nearby Perseus cluster of galaxies, NGC1275, resemble those found around distant radio galaxies and some protogalaxies. The origin and ionization of the filaments are poorly understood and relate to heating and cooling processes in galaxy formation and evolution. We propose here to image the filaments in order to reveal their true small-scale structure and to search for clumps of young stars along them. The observations will produce the first deep high resolution images of the whole filament system and, with our 1 Ms Chandra image, constrain both particle and photon ionization models for its ionization and excitation.

NIC2/ACS/WFC/WFPC 10532 2 Kinematics and morphology of the most massive field disk galaxies at z>1

We propose to obtain 1 orbit NIC-2 images of a sample of the 15 most massive galaxies found at $1 < z < 1.3$. These were culled from over 20, 000 Keck spectra collected as part of DEEP and are unique among high redshift massive galaxy samples in being kinematically selected. We intend to test whether these potentially very young galaxies are likely precursors to massive local disks, assuming no further merging. NIC-2 images provide rest-frame optical morphologies that will show whether they are normal disky systems or instead more disturbed looking objects with multiple subcomponents, mergers, peculiar structure, etc. NIC-2 provides near-IR resolutions sufficient to enable measurements of bulges and disks subcomponents. The near-IR will fill a critical gap in the broad-band SED photometry of the galaxy and its subcomponents to estimate mean stellar ages and stellar masses and to assess whether old stellar bulges and disks are in place at that time. Finally, this sample will yield the first statistically significant results on the $z > 1$ evolution of the Tully-Fisher relation for massive galaxies. In addition, we propose parallel observations with ACS WFC {V and I bands} and WFPC2 {I-band}. These will target up to 700 galaxies at redshifts 0.7 … 1.2 for which the DEEP2 survey has obtained precision redshifts and high-resolution kinematic data. The added HST morphology and color information will allow a variety of detailed studies on dynamical, structural, and photometric evolution of galaxies.

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.

NIC3/ACS/WFC 10504

Characterizing the Sources Responsible for Cosmic Reionization

Our group has demonstrated the role that massive clusters, acting as powerful cosmic lenses, can play in constraining the abundance and properties of low-luminosity star- forming sources beyond z~6; such sources are thought to be responsible for ending cosmic reionization. The large magnification possible in the critical regions of well- constrained clusters brings sources into view that lie at or beyond the limits of conventional exposures such as the UDF, as well as those in imaging surveys being undertaken with IRAC onboard Spitzer. We have shown that the combination of HST and Spitzer is particularly effective in delivering the physical properties of these distant sources, constraining their mass, age and past star formation history. Indirectly, we therefore gain a valuable glimpse to yet earlier epochs. Recognizing the result {and limitations} of the UDF exposure, we propose a systematic search through 6 lensing clusters with ACS and NICMOS for further z~6-7 sources in conjunction with existing deep IRAC data. Our survey will mitigate cosmic variance and extend the search both to lower luminosities and, by virtue of the NICMOS/IRAC combination, to higher redshift. The goal is to count and characterize representative sources at z~6-10 and to delineate the redshift range of activity for the planning of future observations.

ACS/WFC 10258

Tracing the Emergence of the Hubble Sequence Among the Most Luminous and Massive Galaxies

There is mounting evidence that the redshift range 1 < z < 2 was an important era when massive galaxies assembled their stellar content and assumed their present--day morphologies. Despite extensive HST imaging surveys, however, there is very little data in the optical rest frame {i.e., observed near--infrared} on the morphologies of the most luminous galaxies at these redshifts. We propose to image a carefully selected set of 20 of the most luminous, K--band selected GOODS galaxies at 1.3 < z < 2, using NICMOS camera 2. This offers diffraction--limited, critically sampled imaging at 1.6 microns to ensure the best angular resolution for comparison to ACS. The galaxies are chosen to span a simple 4--fold parameter space of morphological and spectral type, in order to provide the most information about the variety of massive galaxy properties in this redshift range. We will investigate the emergence of large scale--length disks, stable spiral structure, mature bulges with red stellar populations, central bar structures, the incidence of disturbed morphology, the existence {or lack thereof} of blue ellipticals, and other questions that concern the evolution and maturation of the brightest, largest, and most massive ordinary galaxies in this critical redshift range.

FGS 10103

FGS Astrometry of a Star Hosting an Extrasolar Planet: The Mass of Upsilon Andromedae d

We propose observations with HST/FGS to determine the astrometric elements {perturbation orbit semimajor axis and inclination} produced by the outermost extra-solar planet orbiting the F8V star Upsilon Andromedae. These observations will permit us to determine the actual mass of the planet by providing the presently unknown sin i factor intrinsic to the radial velocity method which discovered this object. An inclination, i = 30degrees, within the range of one very low precision determination using reanalyzed HIPPARCOS intermediate data products, would produce the observed radial velocity amplitude, K = 66 ms with a companion mass of ~8 M_Jupiter. Such a mass would induce in Upsilon Andromedae a perturbation semi-major axis, Alpha = 0arcs0012, easily within the reach of HST/FGS fringe tracking astrometry. The proposed observations will yield a planetary mass, rather than, as previous investigations have done, only suggest a planetary mass companion.

FLIGHT OPERATIONS SUMMARY:

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

HSTARS:

10390 – GSACQ(2,1,1) failed @ 217/1030z

GSAcq (1,2,2) scheduled at 08:45:11-08:52:30 failed to acquire lock RGA control with QF1STOPF and QSTOP flags set at 219.08:48:10. OBAD’s showed RSS values of 2442.68 & 15.70 respectively. OBAD MAP showed a RSS value of 5.36.

SpaceRef staff editor.