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Daily #4058
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT #4058 PERIOD COVERED: UT February 24,25,26, 2006 (DOY 055,056,057) OBSERVATIONS SCHEDULED NIC1/NIC2/NIC3 8793 NICMOS Post-SAA calibration - CR Persistence Part 4 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. WFPC2 10779 WFPC2 WF4 Temperature Reduction Test #2 A serious anomaly has been found in images from the WF4 CCD in WFPC2. The WF4 CCD bias level appears to have become unstable, resulting in sporadic images with either low or zero bias level. The severity and frequency of the problem is rapidly increasing, and it is possible that WF4 will soon become unusable if no work-around is found. The other three CCDs {PC1, WF2, and WF3} appear to be unaffected and continue to operate properly. This is a second test to further reduce temperatures. Orbits: internal 26, external 1 NIC3 10761 The X-ray Spectral and Optical/IR Flux Variability in Magnetars In the last decade it has become clear that there exists a small subset of pulsars that are powered neither by rotation nor accretion but by the decay of their enormous magnetic fields -- magnetars. The origin of the X-ray emission from magnetar-candidate AXPs {Anomalous X-ray Pulsars} is fairly well understood within the framework of the magnetar model. However, where and how the optical/IR emission is produced is unclear. If, as recent models suggest, the optical/IR emission is magnetospheric, then any variation in the optical/IR flux should be accompanied by variation in the X-ray spectra. We therefore propose for joint Chandra-Hubble observations of two magnetar candidates in order to test the optical/IR emission models for magnetars. ACS/HRC/WFC 10729 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. 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/HRC 10599 Multi-color imaging of two 1 Gyr old debris disks within 20 pc of the Sun: Astrophysical mirrors of our Kuiper We report the first scattered light detections of two debris disk around an F star and a K star using optical coronagraphy and the Hubble Space Telescope. With ages ~1 Gyr, these are the oldest debris disks thus far seen in the optical. We propose deep, multi-roll angle coronagraphic imaging with HST ACS and NICMOS to confirm and characterize the disks in terms of structure and composition. The disks appear to have belt-like morphology that is consistent with the existence of planetary companions or other perturbing bodies. Since these disks are close to our Kuiper Belt in an evolutionary context, detailed understanding of their mass, structure and composition will provide a fresh perspective for inferring the history and properties of our own trans-Neptunian region. ACS/WFC 10597 Resolving the Connection Between Globular Clusters and Low-Mass X-ray Binaries Because of their high central densities, globular clusters {GCs} are efficient producers of low- mass X-ray binaries {LMXBs}. To shed light on the detailed formation mechanism of LXMBs in GCs, we propose to measure accurate structural parameters for hundreds of GCs in NGC 5128: the only giant elliptical galaxy within 5 Mpc of the Milky Way. We will carry out the first complete survey of GCs in the inner region of NGC 5128, measure GC structural parameters of unprecedented acccuracy, and derive GC luminosity profiles in the cluster cores. These measurement will allow us to determine precisely which GC structural properties control the presence of an X-ray source and thus probe the details of the LXMB formation process in GCs. We will additionally use the measured structural parameters to perform the most comprehensive study of the fundamental plane of GCs in early-type galaxies, a fundamental set of correlations which holds key information on GC formation and evolution. 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 10582 Probing The Galaxy-wide Globular Cluster - Low Mass X-ray Binary Connection in Early-type Galaxies The combination of high-resolution imaging from Hubble {HST} and Chandra {CXO} has completely revolutionized our understanding of extragalactic low-mass X-ray binaries {LMXBs} and globular clusters {GCs}; however, studies have been limited by short X-ray exposures and relatively small fields. NGC 4697 amd NGC 4365 are relatively simple elliptical galaxies in the X- ray that will have deep CXO observations. We propose ACS observations in six flanking fields per galaxy to provide a study of the GC-LMXB connection in normal early-type galaxies with unprecedented depth, spatial resolution and areal coverage. Combined with existing central field observations, we will detect ~900 and ~2700 GCs GCs in most of NGC 4697 and all of NGC 4365. These two galaxies will have the greatest number of detected GC-LMXBs to date {~70 & 120}. We will measure the fraction of LMXBs found in GCs, and the fraction of GCs which contain LMXBs, as a function of X-ray luminosity, galactocentric distance, color, GC half-light radius, and local GC specific frequency. We will test existing models of GC formation/evolution and LMXB formation/evolution. Using the radial profile of optical light, GCs, and LMXBS, we will determine the percentage of field LMXBs which may have originated in GCs. 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 10557 Probing Asteroid Families for Evidence of Ultraviolet Space Weathering Effects We propose six HST orbits to obtain UV reflectance spectra covering 200-460 nm of two Vesta asteroid family members, asteroid 832 Karin, and two Karin family members. These observations extend work done under a Cycle 13 AR grant, where we analyzed all of the existing IUE and HST S-class asteroids in the MAST database to investigate the effects of space weathering at UV wavelengths. Our hypothesis is that the manifestation of space weathering at UV wavelengths is a spectral bluing, in contrast with a spectral reddening at visible-NIR wavelengths, and that UV wavelengths can be more sensitive to relatively small amounts of weathering than longer wavelengths. The proposed observations will address two objectives: {1} Measure the UV-visible spectra of 832 Karin and two members of the young Karin family {absolute age of 5.8 My}, in order to determine whether intermediate space weathering is observable in objects likely pristine when they originated from the interior of Karin's pa rent body. {2} Measure the UV-visible spectra of two members of the Vesta family to compare with our analysis of IUE Vesta spectra. These observations will probe Vesta's interior, and test our hypothesis by contrasting the apparent amount of alteration on the surfaces of Vestoids with excavated material on Vesta. ACS/WFC 10543 Microlensing in M87 and the Virgo Cluster Resolving the nature of dark matter is an urgent problem. The results of the MACHO survey of the Milky Way dark halo toward the LMC indicate that a significant fraction of the halo consists of stellar mass objects. The VATT/Columbia survey of M31 finds a similar lens fraction in the M31 dark halo. We propose a series of observations with ACS that will provide the most thorough search for microlensing toward M87, the central elliptical galaxy of the Virgo cluster. This program is optimized for lenses in the mass range from 0.01 to 1.0 solar masses. By comparing with archival data, we can detect lenses as massive as 100 solar masses, such as the remnants of the first stars. These observations will have at least 15 times more sensitivity to microlensing than any previous survey, e.g. using WFPC2. This is due to the factor of 2 larger area, factor of more than 4 more sensitivity in the I-band, superior pixel scale and longer baseline of observations. Based on the halo microlensing results in the Milky Way and M31, we might expect that galaxy collisions and stripping would populate the overall cluster halo with a large number of stellar mass objects. This program would determine definitively if such objects compose the cluster dark matter at the level seen in the Milky Way. A negative result would indicate that such objects do not populate the intracluster medium, and may indicate that galaxy harassment is not as vigorous as expected. We can measure the level of events due to the M87 halo: this would be the best exploration to date of such a lens population in an elliptical galaxy. Star-star lensing should also be detectable. About 20 erupting classical novae will be seen, allowing to determine the definitive nova rate for this giant elliptical galaxy. We will determine if our recent HST detection of an M87 globular cluster nova was a fluke, or indicative of a 100x higher rate of incidence of cataclysmic variables and nova eruptions in globulars than previously believed. We will examine the populations of variable stars, and will be able to cleanly separate them from microlensing. ACS/WFC 10496 Decelerating and Dustfree: Efficient Dark Energy Studies with Supernovae and Clusters We propose a novel HST approach to obtain a dramatically more useful "dust free" Type Ia supernovae {SNe Ia} dataset than available with the previous GOODS searches. Moreover, this approach provides a strikingly more efficient search-and-follow-up that is primarily pre- scheduled. The resulting dark energy measurements do not share the major systematic uncertainty at these redshifts, that of the extinction correction with a prior. By targeting massive galaxy clusters at z 1 we obtain a five-times higher efficiency in detection of Type Ia supernovae in ellipticals, providing a well-understood host galaxy environment. These same deep cluster images then also yield fundamental calibrations required for future weak lensing and Sunyaev-Zel'dovich measurements of dark energy, as well as an entire program of cluster studies. The data will make possible a factor of two improvement on supernova constraints on dark energy time variation, and much larger improvement in systematic uncertainty. They will provide both a cluster dataset and a SN Ia dataset that will be a longstanding scientific resource. ACS/WFC 10486 A Cosmic String Lens Candidate We propose two-band imaging observations with ACS of a cosmic string lens candidate, CSL-1, to look for a feature predicted by the cosmic string model: a low-surface brightness discontinuity in between the two galaxy images. NIC1 10415 A Proper Motion Study of the Ionized Gas in the Vicinity of the Galactic Center Black Hole The Galactic Center's distance of only 8 kpc provides a unique opportunity to study the interaction of a supermassive black hole with its environment at a level of detail not possible for other galaxies. We propose to observe the inner parsec of the Galaxy in the Paschen alpha line with Camera 1 of NICMOS in order to study the kinematics of ionized gas in the vicinity of the supermassive black hole coincident with Sgr A*. Our previous GO program 7842 yielded detailed Pa alpha images revealing complex, filamentary structure at 0.16 arcsec {0.006 pc} resolution. However, proper motions could not be robustly derived from that data set due to the fact that the two epochs were spaced only 7 months apart. In order to follow up on preliminary results showing evidence for high proper motions within 2'' of Sgr A* and to characterize the rest of the central parsec, we propose to obtain two additional epochs within Cycle 13 so that the dataset will comprise independent measurements of the proper motions ranging from intervals of 5 months to 7 years, with the 7 year interval giving a 1 sigma accuracy of 45 km/s. These will be combined with existing radial velocity measurements to provide the first complete characterization of the kinematics of the ionized gas in the central parsec. This is crucial to interpreting the relative importance of gravitational forces, stellar winds, and possible accretion onto or outflow from the black hole. These observations may possibly lead to the first direct observation of gas in the process of accretion {or ejection via a jet} associated with the Galactic Center black hole. The kinematics of the gas may also imply that accretion may be inhibited, and this could explain the low luminosity of Sgr A*. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: 10146 - REacq (2,1,1) results in finelock backup (1,0,1) due to scan step limit exceeded FGS-2 @055/1237z The Target REacq(2,1,1) scheduled at 055/12:37:39 - 12:45:44 Z resulted in finelock backup (1,0,1)using FGS-1, due to scan step limit exceeded on FGS-2. Prior OBAD2 at 055/12:33:09 had total attitude correction (RSS) value of 7.05 arcseconds. 10147 - Gsacq(1,2,2) stop guiding @056/0628z GSacq(1,2,2) scheduled at 056/06:15:40 stop guiding at 06:27:57 and transition from F2G to T2G. There was a Genslew offset request at 06:25:36. 10148 - GSAcq (2,1,2) failed to RGA control @057/2026z GSAcq (2,1,2) scheduled at 057.20:22:12 failed to RGA control. No flags were evident other than already indicated. No ESB messages were received prior to or during Acq. OBAD #1: V1 195.65, V2 -2814.86, V3 -69.91, RSS 2822.51 OBAD #2: V1 -7.04, V2 -12.21, V3 -8.34, RSS 16.37 COMPLETED OPS REQUEST: (None) COMPLETED OPS NOTES: (None) SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 29 28 @057/2026z (HSTAR 10148) FGS REacq 13 13 OBAD with Maneuver 78 78 LOSS of LOCK @056/0628z (HSTAR 10147) SIGNIFICANT EVENTS: (None) |
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