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Daily 3845
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3845 PERIOD COVERED: DOYs 112-114 OBSERVATIONS SCHEDULED ACS/HRC/WFPC2 9827 UV extinction by dust in unexplored LMC environments The ensemble of results from studies of the UV extinction in the Milky Way, Magellanic Clouds {MC}, M31 and M33, indicates a complex dependence of the dust properties with environment, where starburst activity and metallicity are relevant factors. Work in the LMC to date, based on IUE data, has several drawbacks: a} only supergiants could be used, b} they all have moderate extinction, c} the IUE S/N is limited, d} the large IUE slit may include light from other sources, such as scattered light from dust or faint companion stars, e} studies are confined to few {extreme} environments. We propose to obtain UV extinction curves more accurate than previous ones, sampling four environments in the LMC with different levels of star formation activity, including the general field, hitherto unexplored. The results will characterize the properties of dust in different conditions, at the LMC metallicity, which is useful to interpret integrated properties of distant galaxies, as well as GALEX upcoming UV surveys. A complementary study is planned with FUSE in the far-UV range. The combined results will provide insight on the properties of small grains. ACS/WFC 9811 Establishing the Metallicity Distribution in Normal Giant Ellipticals NGC 3377 and 3379, the Leo Group ellipticals at d=11 Mpc, are the nearest E galaxies commonly regarded to be structurally" normal", and as such, they are keystone objects for understanding the evolution and early star formation history of large ellipticals. The ACS/WFC camera now gives us the ability to obtain the metallicity distribution function {MDF} of their stellar population by direct resolution and photometry of their halo stars. To do this, we will follow the same highly successful techniques we have previously used for NGC 5128 with WFPC2 {V, I} imaging: the {V-I} colors of the brightest red-giant stars are highly sensitive to metallicity, and their locations in the color-magnitude diagram can be used for direct construction of the MDF. This will be a major step forward to understanding the formation history of these cosmologically dominant galaxies. 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. NIC1/NIC2/NIC3 10454 Extreme count rates linearity test for NICMOS This NICMOS calibration proposal tests the linearity of the detectors at count rates falling at the low and high extremes of what is feasible. This program is a response to the discovery that grism observations obtained with NIC3 show a systematic offset from spectra taken with STIS and ACS in the 0.8-1.0 micron overlap region. The observations are consistent with a NIC3 sensitivity that depends on incident flux, i.e. count rate. By observing one bright star {BD+17D4708, the Sloan Digital Sky Survey absolute standard} and two faint stars {SNAP-2, a solar analog star; WD1657+343, a white dwarf} in a number of filters we will check whether this is an intrinsic feature of the all NICMOS detectors, something intrinsic to NIC3, or a result of a not understood effect of the grism observations. We will furthermore be able to test whether the effect has a wavelength dependence. The data will be reduced in exactly the same fashion as has been done before for the photometric calibration program, so a direct comparison with previous data can be made. In addition, we will obtain extra spectroscopic data on WD1657+343, the faintest and best modeled white dwarf of the stars on which the original discovery of the non-linearity was made. This will reduce the errors in this spectrum from 5% to 2% and will allow a better estimate of the effect. In order to ease scheduling, there are no time constraints specified in the proposal. However, because of the potentially important implications of this effect, it is very important that these orbits be scheduled as soon as possible. They could be critical for the proper calibration of NICMOS The targets have visibility 1} BD+17D4708: 16 Apr - 17 Jan 2} SNAP-2: 3 Feb-1 Mar 3} WD1657+343: 3 Feb-26 Feb ACS/HRC/WFC 10438 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. ACS/HRC/WFC 10436 Black Hole Growth and the Black Hole Mass -- Bulge Relations for AGNs Recent work has shown that the mass of a black hole is tightly correlated with the bulge mass of its host galaxy. This relation needs to be understood in the context of black hole growth in its active phase. Highly accreting AGNs, like narrow line Seyfert 1 galaxies {NLS1s}, are found to lie below the black hole mass -- bulge velocity dispersion correlation of normal galaxies and broad line AGNs. This result was obtained using FWHM{[OIII]} as a surrogate for the bulge velocity dispersion. To test this result we propose to obtain high resolution images of 10 NLS1s that do not lie on the black hole mass--sigma relation and measure accurate bulge parameters {luminosity and effective radius}. We will obtain an alternate handle on the bulge velocity dispersion through the fundamental plane relations and also find the locus of these NLS1s on the black hole mass--bulge luminosity plane. Testing this result is crucial to understanding the role of accretion on black hole growth, the observed correlations of the black hole mass with the bulge, and the formation and evolution of galaxies. ACS/HRC 10434 Particle accelerators in space: resolving them for the first time The detection of optical counterparts of hot spots in radio galaxies has been a challenge in astrophysics since the 1960s. Being located at several 100 kpc away from the AGN, they represent the most striking sites of interaction between the AGN ejecta and the ambient inter-galactic medium. Particle acceleration is thought to drive their emission and therefore, due to their remote locations, hot spots are the best laboratories to study the physics of that mechanism in detail. Using carefully directed selection criteria and the VLT we have discovered hot spots in the optical at an unprecedented detection rate, all of them disclosing very intriguing structure. This structure pinpoints the regions where electrons are accelerated to highly relativistic energies -- the particle accelerators. With HST we aim at resolving these accelerators for the very first time. This will enable us to establish the nature and origin of these relativistic particles in the hot spots of radio galaxies. The results of these studies not only represent a key for understanding the evolution of radio sources but also provide important input to plasma acceleration problems in general. ACS/WFC 10412 The host galaxies of dust-reddened quasars We have used the 2MASS near-infrared and FIRST radio surveys, together with the Palomar Observatory Sky Survey plates to select a sample of dust-reddened, radio- intermediate quasars. We wish to use ACS to study the host galaxies of these quasars. The dust reddening of the quasars makes it possible to study the hosts at rest-frame optical-UV wavelengths much more easily than the hosts of normal quasars of similar bolometric luminosity. Our study will compare the hosts of our dust-reddened quasars to those of normal quasars from the HST archive to test the hypothesis that dust-reddened quasars are young objects, whose hosts still show morphological evidence of recent merger events which triggered the quasar. ACS/HRC 10391 Wavelength and Flux Calibration of the ACS prisms The wavelength calibration of the SBC {PR110L and PR130L} and HRC {PR200L} prisms will be established by observing a planetary nebula in the LMC and QSOs at carefully selected redshifts. Flux calibrations will be derived for each prism by observing white dwarf standards. ACS/HRC/WFC 10389 ACS CCDs daily monitor - Cycle 13 - Part 2 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. ACS/HRC 10377 ACS Earth Flats High signal sky flats will be obtained by observing the bright Earth with the HRC and WFC. These observations will be used to verify the accuracy of the flats currently used by the pipeline and will provide a comparison with flats derived via other techniques: L- flats from stellar observations, sky flats from stacked GO observations, and internal flats using the calibration lamps. Weekly coronagraphic monitoring is required to assess the changing position of the spots. ACS/WFC 10369 ACS internal CTE monitor The charge transfer efficiency {CTE} of the ACS CCD detectors will decline as damage due to on-orbit radiation exposure accumulates. This degradation will be closely monitored at regular intervals, because it is likely to determine the useful lifetime of the CCDs. All the data for this program is acquired using internal targets {lamps} only, so all of the exposures should be taken during Earth occultation time {but not during SAA passages}. This program emulates the ACS pre-flight ground calibration and post-launch SMOV testing {program 8948}, so that results from each epoch can be directly compared. Extended Pixel Edge Response {EPER} and First Pixel Response {FPR} data will be obtained over a range of signal levels for both the Wide Field Channel {WFC}, and the High Resolution Channel {HRC}. ACS/HRC 10330 Coronagraphic search for disks around nearby stars We will use the coronagraphic and imaging modes of the High Resolution camera to study of the role of circumstellar disks in planetary system formation over timescales of ~1-1000 Myr. Our targets comprise pre Main-Sequence {MS} and MS stars, selected by infrared excess, and targets selected from SIRTF surveys. Some targets, like Beta Pictoris have debris disks that have been detected at optical or near-IR wavelengths, while others have disks inferred from mid-IR or ISO observations. We will obtain multicolor images of each target's circumstellar environment for the purpose of {1} detecting and characterizing disk morphologies over all scales {including warps and regions of enhanced or depleted density}, and {2} seeking evidence of embedded planets. Direct and occulted images will be recorded for studying the disks within 2 arcseconds of these targets; the coronagraph will be used to image the outer regions of the disks. Together with existing infrared observations, we will provide constraints on the sizes, distribution, and composition of dust grains. Unconfirmed disks will first be imaged in F606W, and if they exist we may later observe them in F435W and F814W. ACS/HRC/WFC 10263 SAINTS - Supernova 1987A Intensive Survey SAINTS is a program to observe SN 1987A, the brightest supernova in 383 years, as it transforms into supernova remnant {SNR} 1987A, the youngest supernova remnant. HST is the unique and perfect match in scale and in field for spatially-resolved observations of SN 1987A. Rapid changes are taking place in a violent encounter between the fastest-moving debris and the circumstellar ring. This one-time-only event, leading to suddenly appearing hotspots and new emission that can reveal previously hidden gas, is powered by shocks that can be studied simultaneously with HST and with Chandra to great advantage. Both the optical and X-ray flux from the ring are rising rapidly so prompt observations are needed in Cycle 13. Our previous observations reveal a remarkable reverse shock moving upstream through the expanding debris. The reverse shock provides a powerful tool for dissecting the radial structure of the vanished star. The debris from the explosion itself, still excited by radioactivity, is now well resolved by ACS and seen to be aspherical, providing direct clues to the mechanism of the explosion. Many questions about SN 1987A remain unanswered. SAINTS is a comprehensive attempt to use HST to establish the facts of SN 1987A, help to answer interesting questions, and to observe the birth of SNR 1987A. ACS/HRC 10259 Planetary nebulae in the SMC: a study of stellar evolution and populations in an extremely low-metallicity environment The final phase of the evolution of low- and intermediate-mass stars, the planetary nebula {PN} ejection, is thought to largely contribute to the carbon and nitrogen enrichment in galaxies, in particular in old stellar populations. Stellar generations forming from a carbon- and nitrogen-enriched medium are a necessary condition for planetary and life formation. It is essential to understand how stars go through the process of shedding their chemically-enriched shells, and to test the predictions of stellar evolution theory on the relationship between stellar mass and elemental enrichment. Magellanic Cloud PNs are ideal probes for this study. Their abundances can be directly related to the mass of the central stars and to that of the stellar progenitor, without the great {distance and reddening} uncertainties that affect Galactic PNs. The UV lines are essential for calculating the abundances of the element related to stellar evolution {C, N, O} and to progenitor populations {e.g., Ne}. We propose to acquire UV spectroscopy of the SMC PNs whose morphology and central star properties has been previously determined by us with HST. We will derive the {C, N, O} abundance-to-mass relation, and determine the extent to which the mass of the progenitors of asymmetric PNs exceed that of symmetric PNs. We will also test the PN luminosity function, and probe cosmic recycling, in a very low-metallicity environment. ACS/HRC 10198 Probing the Dynamics of the Galactic Bar through the Kinematics of Microlensed Stars The observed optical depths to microlensing of stars in the Galactic bulge are difficult to reconcile with our present understanding of Galactic dynamics. The main source of uncertainty in those comparisons is now shifting from microlensing measurements to the dynamical models of the Galactic bar. We propose to constrain the Galactic bar models with proper motion observations of Bulge stars that underwent microlensing by determining both the kinematic identity of the microlensed sources and the importance of streaming motions. The lensed stars are typically farther than randomly selected stars. Therefore, our proper motion determinations for 36 targeted MACHO events will provide valuable constraints on the dynamics of bulge stars as a function of distance. The first epoch data for our proposed events is already available in the HST archive so the project can be completed within a single HST cycle. The exceptional spatial resolution of HST is essential for completion of the project. Constraints on the total mass in the bulge will ultimately lead to the determination of the amount of dark matter in inner Galaxy. ACS/WFC 10174 Dark-matter halos and evolution of high-z early-type galaxies Gravitational lensing and stellar dynamics provide two complementary methods to determine the mass distribution and evolution of luminous and dark-matter in early-type {E/S0} galaxies. The combined study of stellar dynamics and gravitational lensing allows one to break degeneracies inherent to each method separately, providing a clean probe of the internal structure of massive galaxies. Since most lens galaxies are at redshifts z=0.1-1.0, they also provide the required look-back time to study their structural and stellar-population evolution. We recently analyzed 5 E/S0 lens galaxies between z=0.5 and 1.0, combining exquisite Hubble Space Telescope imaging data with kinematic data from ground-based Keck spectroscopy, placing the first precise constraints on the dark- matter mass fraction and its inner slope beyond the local Universe. To expand the sample to ~30 systems -- required to study potential trends and evolution in the E/S0 mass profiles -- we propose to target the 49 E/S0 lens-galaxy candidates discovered by Bolton et al. {2004} from the Sloan Digital Sky Survey {SDSS}. With the average lens rate being 40% and some systems having a lensing probability close to unity, we expect to discover ~20 strong gravitational lenses from the sample. This will triple the current sample of 9 E/S0 systems, with data in hand. With the sample of 30 systems, we will be able to determine the average slope of the dark-matter and total mass profile of E/S0 galaxies to 10% and 4% accuracy, respectively. If present, we can simultaneously detect 10% evolution in the total mass slope with 95% confidence. This will provide unprecedented constraints on E/S0 galaxies beyond the local Universe and allow a stringent test of their formation scenarios and the standard cosmological model. ACS/WFC/WFPC2 10129 Resolving Globular Clusters in NGC 1399 We intend to use the ACS/WFC to measure structural parameters {half light radius, King core radius and concentration parameter} of individual globular clusters {GCs} in NGC 1399. Very little is known about structural parameters of globular clusters as a function of radius outside the Local Group. The proposed observations, arranged in a 3x3 ACS mosaic, will allow us to perform the first detailed wide-field study of structural parameters of globular clusters in a giant elliptical galaxy. In particular we will: 1} study the size-galactocentric distance relation of globular clusters out to ~55 kpc {~1.6 eff. radius of the GCS} and determine whether the observed differences in sizes between metal-rich and metal-poor globular cluster in early-type galaxies are primordial and thereby reflect fundamental differences in formation, or are due to projection effects; 2} match the GC position observed with HST/ACS with X-ray binaries identified over the full Chandra field, and use the above sizes to constrain physical models for X-ray binary formation in GCs. 3} The wealth of ground-based data available for this system {photometry+spectroscopy}, will allow us to correlate the structural properties with other GC properties, such as their chemical composition, luminosity, etc. ACS/WFC/WFPC2 10092 The COSMOS 2-Degree ACS Survey We will undertake a 2 square degree imaging survey {Cosmic Evolution Survey -- COSMOS} with ACS in the I {F814W} band of the VIMOS equatorial field. This wide field survey is essential to understand the interplay between Large Scale Structure {LSS} evolution and the formation of galaxies, dark matter and AGNs and is the one region of parameter space completely unexplored at present by HST. The equatorial field was selected for its accessibility to all ground-based telescopes and low IR background and because it will eventually contain ~100, 000 galaxy spectra from the VLT-VIMOS instrument. The imaging will detect over 2 million objects with I 27 mag {AB, 10 sigma}, over 35, 000 Lyman Break Galaxies {LBGs} and extremely red galaxies out to z ~ 5. COSMOS is the only HST project specifically designed to probe the formation and evolution of structures ranging from galaxies up to Coma-size clusters in the epoch of peak galaxy, AGN, star and cluster formation {z ~0.5 to 3}. The size of the largest structures necessitate the 2 degree field. Our team is committed to the assembly of several public ancillary datasets including the optical spectra, deep XMM and VLA imaging, ground-based optical/IR imaging, UV imaging from GALEX and IR data from SIRTF. Combining the full-spectrum multiwavelength imaging and spectroscopic coverage with ACS sub-kpc resolution, COSMOS will be Hubble's ultimate legacy for understanding the evolution of both the visible and dark universe. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9787: GS Acq (1,2,1) Failure to RGA Control 5/113/11:19:28z. GSAcq (1,2,1) scheduled at 113/11:15:40 failed to enter Fine Lock, with Search Radius Limit Exceeded at 113/11:19:28. All subsequent attempts failed. Possible Observations affected: ACS 203-206, NIC 39-43 REAcq's scheduled at 113/12:51:30, 113/14:27:27, 113/16:03:23 all failed to RGA control due to Search Radius Limit Exceeded. Under investigation. COMPLETED OPS REQs: 17425-0 Genslew for Proposal 10263 Slot#3 @112/1705z 17426-0 R/T Map @113/1311z 17427-0 R/T Map @113/1612z OPS NOTES EXECUTED: 1331-0 Change JERRCNT Limit @111/2130z SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 24 23 @113/1119z (HSTAR#9787) FGS Reacq 22 19 @113/1251z,1427z,1603z (HSTAR#9787) FHST Update 40 40 LOSS of LOCK SIGNIFICANT EVENTS: The Hubble Space Telescope Team today celebrates the 15th anniversary of the launch of the Hubble Space Telescope (April 24, 1990). |
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