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Daily 3880
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3880 PERIOD COVERED: UT June 12-13, 2005 (DOY 163-164) OBSERVATIONS SCHEDULED WFPC2 9740 CIII] Imagery of Planetary Nebulae and HII Regions -- A Snap Program We propose to undertake a SNAP program of WFPC2 imagery of several planetary nebulae and extragalactic HII regions with the F185W filter to study the spatial variation of the CIII] 1909 Angstrom emission lines across the nebulae. Much of our current knowledge of carbon abundances in planetary nebulae and HII regions are based on UV spectroscopic observations of this line yet there have not been any studies of its spatial variations in nebulae compared to several of the prominent optical lines {e.g. [OIII] 5007 Angstroms}. Such observations, coupled with photoionization modeling of the nebulae, will enable us to assess the utility of using the CIII] line in abundance calculations of C/O and C/H in nebulae and possibly permit improved empirical emission-line diagnostic techniques for ionization corrections to get the elemental carbon abundances from C++/O++ observations based on CIII]/[OIII] 1909/5007. We also plan to study the spatial variation of the CIII] 1909 Angstrom collisionally excited lines against the CII 4267 Angstrom permitted line in many of the nebulae using previous and planned ground-based longslit echelle spectroscopy coupled with the HST WFPC2 F185W imagery. NIC1/NIC2/NIC3 8792 NICMOS Post-SAA calibration - CR Persistence Part 3 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. NIC3 10709 Linearity Test for Long Grism Integrations In cycle 12, 24 orbits were used to measure the NICMOS grism mode sensitivities and to establish a set of IR flux standards with a goal of 1% accuracy. However, the short wavelength response shows a 5.6%/dex apparent non-linearity in the overlap region {Bohlin, Lindler, & Riess NICMOS ISR 2005-02}. Studies of the _ima files for both the grism data and for stellar photometry suggest that the NICMOS count rates are a monotonically rising function of integration time. The typical integration time of the grism observations are typically 1-2min with a maximum of 3min, while the most interesting science observations are typically 5-10x longer. At a declination of +72deg, a previous observation of WD1057+719 obtained 04Apr2 reached at an exposure time of ~3min for each of 15 dither positions. By reducing the dithers to 2, exposure times of 20-25min will be obtained. This program addresses the NICMOS count rate growth from 0.8-1.9microns as a function of integration times that are relevant for faint source science. Results will include count rate growth curves for several wavelength bins covering the range of maximum non-linearity around 1micron to where the previously measured non-linearity disappears around 1.7microns. The count rates for the existing short integrations can be attached seamlessly to those for the new long integrations, because NICMOS sensitivities are constant with time to 1%. A definitive answer is expected to the question of whether the count rates rise enough with exposure time to explain the full apparent grism non-linearity for short exposure times and whether the rise is enough to explain the apparent lack of any non-linearity in the prime science from photometry of faint point sources. II. NICMOS Non-Linearity Measurement as a Function of Wavelength WD1057+719 is one of two faint stars used by {Bohlin, Lindler, & Riess NICMOS ISR 2005-02} to establish the wavelength dependence of the non-linearity. However, the uncertainty in the linearity correction vs. wavelength is as big as 3%/dex at 1.8microns. These new data should reduce that uncertainty by sqrt{2} and answer the crucial question of whether the non-linearity changes slope from positive to negative longward of 1.7microns. S/C 10706 SMS spanning anneal for Flight Software Update {ACS} This is an anneal that will take the place of the regularly scheduled anneal, and will span a calendar boundary. 1. Visit 1 must be scheduled to start within 6 hours of an SMS boundary. ACS/WFC 10493 A Survey for Supernovae in Massive High-Redshift Clusters We propose to measure, to an unprecedented 30% accuracy, the SN-Ia rate in a sample of massive z=0.5-0.9 galaxy clusters. The SN-Ia rate is a poorly known observable, especially at high z, and in cluster environments. The SN rate and its redshift dependence can serve as powerful discrimiminants for a number of key issues in astrophysics and cosmology. Our observations will: 1. Put clear constraints on the characteristic SN-Ia "delay time, " the typical time between the formation of a stellar population and the explosion of some of its members as SNe-Ia. Such constraints can exclude entire categories of SN-Ia progenitor models, since different models predict different delays. 2. Help resolve the question of the dominant source of the high metallicity in the intracluster medium {ICM} - SNe-Ia, or core-collapse SNe from an early stellar population with a top-heavy IMF, perhaps those population III stars responsible for the early re-ionization of the Universe. Since clusters are excellent laboratories for studying enrichment {they generally have a simple star-formation history, and matter cannot leave their deep potentials}, the results will be relevant for understanding metal enrichment in general, and the possible role of first generation stars in early Universal enrichment. 3. Reveal, via nuclear variability, the AGN fraction in clusters at this redshift, to be compared with the field AGN fraction. This will be valuable input for understanding black-hole demographics, AGN evolution, and ICM energetics. 4. Potentially discover intergalactic cluster SNe, which can trace the stripped stellar population at high z. NIC2 10428 The colours of QSO host galaxies at z=2 and the evolution of their stellar masses We propose to use NICMOS imaging to measure the rest-frame optical/UV colours of a complete sample of 10 QSO host galaxies at redshifts between z=1.5 and z=2. From our cycle 11 HST observations {the GEMS project} we know that QSO host galaxies at redshifts of z~1 show blue colors despite having early-type morphologies. This is in excellent agreement with recent SDSS results on low-z AGN hosts, suggesting that QSO-type activity in galaxies correlates strongly with the presence of a young stellar population. Our proposed NICMOS observations will allow us to test the validity of this hypothesis out to z~2, by relating the observed QSO host colours to those of normal galaxies at similar redshifts taken from GOODS. We have already established within GEMS that the QSO hosts in our sample possess substantial UV luminosities, most likely originating from young stars. Knowing rest-frame colors, we can estimate stellar ages and stellar masses. For the first time will it be possible to determine the evolution of stellar masses in QSO host galaxies from z=2, the epoch of maximum QSO activity, to the present. Our results will shed light on the relation between nuclear activity and the star formation history of galaxies, and how these processes may jointly drive the cosmic evolution of QSOs and galaxies. 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/WFC/WFPC2 10402 The Formation and Evolution of Spirals: An ACS and WFPC2 Imaging Survey of Nearby Galaxies Over 50% of galaxies in the local universe are spirals. Yet the star formation histories and evolution of this crucial population remain poorly understood. We propose to combine archival data with new ACS/WFC and WFPC2 observations of 11 galaxies, to tackle a comprehensive investigation of nearby spirals covering the entire spiral sequence. The new observations will fill a serious deficiency in HST's legacy, and maximize the scientific return of existing HST data. The filter combination of UBVI, and Halpha is ideal for studying stellar populations, dust properties, and the ISM. Our immediate scientific objectives a {i} to use the resolved cluster populations, both young massive clusters and ancient globular clusters as a chronometer, to understand how spirals assembled as a function of time; {ii} study the rapid disruption properties of young clusters; and {iii} understand dust distributions in spirals from pc to kpc scales. Each of these goals provides an important step towards charting the evolution of galaxies, and an essential baseline for interpreting the galaxy populations being surveyed in both the early and present universe. The resolution of our survey, which exploits the excellent imaging capabilities of HST's two optical cameras, will enable us to understand the record of star cluster, and galaxy formation in a level of detail which is not possible for more distant systems. Finally, the proposed observations will provide a key to interpret an extensive, multiwavelength archive of space- and ground- based data at lower spatial resolution {SPITZER, CHANDRA, GALEX, NICMOS P alpha and H band imaging} for local spirals. ACS/HRC/WFC 10399 Accurate and Robust Calibration of the Extragalactic Distance Scale with the Maser Galaxy NGC4258 II The extragalactic distance scale {EDS} is defined by a comparison of Cepheid Period-Luminosity {PL} relations for nearby galaxies and the LMC, whose uncertain distance is thereby the SOLE anchor. Studies of masers orbiting the central black hole in NGC4258 have provided the most accurate extragalactic distance ever {7.2+/-0.5 Mpc}, and new radio data and analysis techniques will reduce the uncertainty to 3.5% {0.07 mag} by 2005. Since this distance is well determined and based on geometric arguments, NGC4258 can provide a much needed new anchor for the EDS. Ultimately, the combination of an independent measurement of H0 and measurements of CMB fluctuations {e.g., WMAP} can be used to directly constrain cosmological parameters including the equation of state of dark energy. In our Cycle 12 proposal, we defined a program spanning two cycles. The Cycle 12 portion was accepted. We have acquired WFC images and are constructing well sampled PL relations in 3 colors {BVI}. The purpose of the Cycle 13 observations is to address systematic sources of error and is crucial for the success of the entire program. To disentangle the effects of reddening and metallicity, and to characterize the effects of blending, we require 50 orbits to obtain H-band photometry {NICMOS/NIC2} and high resolution images {ACS/HRC}. 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 program will be for the entire lifetime of ACS. WFPC2 10359 WFPC2 CYCLE 13 Standard Darks This dark calibration program obtains dark frames every week in order to provide data for the ongoing calibration of the CCD dark current rate, and to monitor and characterize the evolution of hot pixels. Over an extended period these data will also provide a monitor of radiation damage to the CCDs. ACS/HRC 10262 The 3D Morphology of the Extreme Red Supergiant VY Cma The extreme RSG and powerful OH/IR source VY CMa is surrounded by an asymmetric reflection nebula dominated by a prominent nebulous arc, bright filamentary arcs, and several clumps of dusty knots that are evidence for multiple and asymmetric mass loss events. Our groundbased velocities show that these structures are kinematically distinct from the gneral flow of the diffuse gas and may be directional. We have speculated that these arcs and knots may be caused by localized activity on the star involving convection and possibly magnetic fields analogous to lower mass stars. If correct this would have important implications for the causes of high mass loss events in evolved massive stars. Fortunately, VY CMa provides us with an opportunity to learn more about its possible mass loss mechanisms and history from the morphology of its ejecta. We propose to use polarimetry and second epoch images combined with our radial velocities to map the morphology of the nebula and the discrete structures embedded in it. 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. FGS 10197 The Astrophysical Parameters of Very Metal-Poor Halo Binaries Little is currently known concerning the mass-luminosity relation {MLR} of Population II stars. In Cycle 10, we began an initial study with FGS1 to resolve a sample of known spectroscopic binaries preselected as high-velocity and/or low metallicity objects. This has resulted in significant new information about the astrophysical parameters of metal-poor stars, but was limited mainly to intermediate metallicities, not to true Population II stars. A new sample of metal- poor spectroscopic binaries identified by Latham and his collaborators {e.g. Latham et al 2002} contains three new very metal-poor objects resolvable with FGS. We propose to observe these binaries and obtain additional observations of two very important resolved targets from our initial sample. As with that program, we will couple the already-known spectroscopic orbits with astrometric information which only FGS can deliver at present. To ensure that the most will be gained from these data, we also request observations of three metal-poor single stars to be used as calibration objects. In combination with results from our previous program, these observations can be expected to resolve the question of the location of the Population II main sequence and give valuable insight into the accuracy of isochrone fitting for determination of globular clusters ages. Due to the combination of target magnitudes and expected separations, no object in this sample can be resolved without the unique capabilities of FGS. NIC2 10173 Infrared Snapshots of 3CR Radio Galaxies Radio galaxies are an important class of extragalactic objects: they are one of the most energetic astrophysical phenomena and they provide an exceptional probe of the evolving Universe, lying typically in high density regions but well-represented across a wide redshift range. In earlier Cycles we carried out extensive HST observations of the 3CR sources in order to acquire a complete and quantitative inventory of the structure, contents and evolution of these important objects. Amongst the results, we discovered new optical jets, dust lanes, face-on disks with optical jets, and revealed point-like nuclei whose properties support FR-I/BL Lac unified schemes. Here, we propose to obtain NICMOS infrared images of 3CR sources with z0.3 as a major enhancement to an already superb dataset. We aim to deshroud dusty galaxies, study the underlying host galaxy free from the distorting effects of dust, locate hidden regions of star formation and establish the physical characteristics of the dust itself. We will measure frequency and spectral energy distributions of point-like nuclei, expected to be stronger and more prevalent in the IR, seek spectral turnovers in known synchrotron jets and find new jets. We will strongly test unified AGN schemes and merge these data with existing X-ray to radio observations. The resulting database will be an incredibly valuable resource to the astronomical community for years to come. WFPC2 10170 Atmospheric Variability on Uranus and Neptune We propose Snapshot observations of Uranus and Neptune to monitor changes in their atmospheres on time scales of weeks, months, and years. Uranus is rapidly approaching equinox in 2007, with another 4 degrees of latitude becoming visible every year. Recent HST observations during this epoch {including 6818: Hammel, Lockwood, and Rages; 7885: Hammel, Karkoschka, and Marley; 8680: Hammel, Rages, Lockwood, and Marley; and 8634: Rages, Hammel, Lockwood, Marley, and McKay} have revealed strongly wavelength-dependent latitudinal structure and the presence of numerous visible-wavelength cloud features in the northern hemisphere. Long-term ground-based observations {Lockwood and Thompson 1999} show seasonal brightness changes whose origins are not well understood. Recent near-IR images of Neptune obtained using adaptive optics on the Keck Telescope together with images from our Cycle 9 Snapshot program {8634} show a general increase in activity at south temperate latitudes as well as the possible development of another Great Dark Spot. Further Snapshot observations of these two dynamic planets will elucidate the nature of long-term changes in their zonal atmospheric bands and clarify the processes of formation, evolution, and dissipation of discrete albedo features. ACS/WFC 10152 A Snapshot Survey of a Complete Sample of X-ray Luminous Galaxy Clusters from Redshift 0.3 to 0.7 We propose a public, uniform imaging survey of a well-studied, complete, and homogeneous sample of X-ray clusters. The sample of 73 clusters spans the redshift range between 0.3-0.7. The samples spans almost 2 orders of magnitude of X-ray luminosity, where half of the sample has X-ray luminosities greater than 10^44 erg/s {0.5-2.0 keV}. These snapshots will be used to obtain a fair census of the the morphology of cluster galaxies in the cores of clusters, to detect radial and tangential arc candidates, to detect optical jet candidates, and to provide an approximate estimate of the shear signal of the clusters themselves, and potentially an assessment of the contribution of large scale structure to lensing shear. ACS/HRC 10144 The Gas Environment of Comet 9P/Tempel 1 During the Deep Impact Encounter We propose a series of observations of the periodic comet 9P/Tempel 1 in conjunction with NASA's Deep Impact mission. This mission is a spacecraft that will release a 360 kg impactor into the nucleus of the comet on July 4, 2005. Our primary objective is to study the generation and evolution of the gaseous coma resulting from this impact. To this end we plan to obtain ultraviolet spectra during, and following the impact. As a secondary objective we will obtain wide-band images of the visual outburst resulting from the impact. We also plan to use the high resolution capability of the ACS/HRC, in conjunction with the camera on board the spacecraft, two weeks prior to impact, to determine the spatial orientation of active jets emanating from the comet's nucleus and to assess the potential hazards of these jets to the spacecraft. ACS/WFC 10135 Unveiling the Progenitors and Physics of Cosmic Explosions GRBs and XRFs are clearly highly asymmetric explosions and require a long-lived power source {central engine}. In contrast, nearby core-collapse events are essentially spherical explosions. However, the failure of spherical neutrino driven collapses has led to the idea that asymmetric energy release is essential for the explosion. The recent finding of a Type Ic SN in GRB 030329, the association of the low energy event GRB 980425 with SN 1998bw, the theoretical development discussed above and the rise of collapsar models make it timely to consider whether all these explosions contain engines. Given the uncertainties in theoretical modeling it is clear that observations are needed to guide models. A priori there is little reason to expect connection between the ultra-relativistic jet that powers the GRB and the explosive nucleosynthesis of the ~0.5 solar masses of Nickel-56 that powers the accompanying supernova. We propose a comprehensive program of ACS photometric searches {and measurements} for SNe associated with GRBs and XRFs. In concert, we will undertake ground- based spectroscopy to determine velocity widths, and measure engine parameters from pan- chromatic afterglow observations. Our goal is to produce a comprehensive database of engine and SN physical parameters against which theoretical modeling will be guided. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTARS: 9846 - GSACQ(2,1,1) results in finelock backup (2,0,2) @ 164/1502z COMPLETED OPS REQUEST: (None) COMPLETED OPS NOTES: (None) SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 8 8 FGS Reacq 8 8 FHST Update 16 16 LOSS of LOCK SIGNIFICANT EVENTS: (None) |
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