#1
|
|||
|
|||
Daily 3491
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3491 PERIOD COVERED: DOYs 318-320 OBSERVATIONS SCHEDULED ACS 9984 Cosmic Shear With ACS Pure Parallels Small distortions in the shapes of background galaxies by foreground mass provide a powerful method of directly measuring the amount and distribution of dark matter. Several groups have recently detected this weak lensing by large-scale structure, also called cosmic shear. The high resolution and sensitivity of HST/ACS provide a unique opportunity to measure cosmic shear accurately on small scales. Using 260 parallel orbits in Sloan textiti {F775W} we will measure for the first time: beginlistosetlength sep0cm setlengthemsep0cm setlength opsep0cm em the cosmic shear variance on scales 0.7 arcmin, em the skewness of the shear distribution, and em the magnification effect. endlist Our measurements will determine the amplitude of the mass power spectrum sigma_8Omega_m^0.5, with signal-to-noise {s/n} ~ 20, and the mass density Omega_m with s/n=4. They will be done at small angular scales where non-linear effects dominate the power spectrum, providing a test of the gravitational instability paradigm for structure formation. Measurements on these scales are not possible from the ground, because of the systematic effects induced by PSF smearing from seeing. Having many independent lines of sight reduces the uncertainty due to cosmic variance, making parallel observations ideal. STIS 9973 Intensive Coverage of the Eta Carinae Event in 2003 For a variety of reasons, HST can provide a very special and unique data set when Eta Car experiences its next spectroscopic event in mid-2003. Explaining the phenomenon is only part of the motivation. This star and its ejecta have unique characteristics that make them important for several branches of astrophysics; and when a spectroscopic event occurs, it's like varying the parameters in an experiment {or rather, set of experiments}. The 2003 event may be the only chance in the forseeable future to obtain such a data set, especially with HST. Eta Carinae has extreme parameters; it is mysterious in surprisingly basic ways; and HST/STIS can gather useful data on it at a terrific rate. As we explain below, the proposed data set will be valuable in several independent ways: It will help solve a specific set of current problems, it will constitute a large and unique archival data base for both stellar and nebular astrophysics, and it will be well-suited for educational uses. FGS 9883 Parallaxes of Extreme Halo Subgiants: Calibrating Globular Cluster Distances and the Ages of the Oldest Stars The ages of the oldest stars are a key constraint on the evolution of our Galaxy, the history of star formation, and cosmological models. These ages are usually determined from globular clusters. However, it is alternatively possible to determine ages of extreme Population II subgiants in the solar neighborhood based on trigonometric parallaxes, without any recourse to clusters. This approach completely avoids the vexing issues of cluster distances, reddenings, and chemical compositions. There are 3 known nearby, extremely metal-deficient Pop II subgiants with Hipparcos parallax errors of 6-11% which are available for such age determinations. At present, based on the latest isochrones, the derived ages of these stars {HD 84937, HD 132475, and HD 140283} are all close to 14 Gyr, uncomfortably close to or higher than current estimates of the age of the universe. However, the errors in the Hipparcos parallaxes imply uncertainties of at least 2 Gyr in the ages of the 3 stars. We propose to measure parallaxes of these three Pop II subgiants using HST's Fine Guidance Sensor 1R. We expect to reduce the Hipparcos parallax error bars by factors of 5-6, providing the most stringent test yet of current theoretical stellar models of Pop II stars and pushing the age uncertainties to below 0.5 Gyr. These data will also provide a major new constraint on the distance scale of globular clusters, with wide implications for stellar evolution and the calibration of Pop II standard candles. NIC/NIC3 9865 The NICMOS Parallel Observing Program We propose to continue managing the NICMOS pure parallel program. Based on our experience, we are well prepared to make optimal use of the parallel opportunities. The improved sensitivity and efficiency of our observations will substantially increase the number of line-emitting galaxies detected. As our previous work has demonstrated, the most frequently detected line is Halpha at 0.7z1.9, which provides an excellent measure of current star formation rate. We will also detect star-forming and active galaxies in other redshift ranges using other emission lines. The grism observations will produce by far the best available Halpha luminosity functions over the crucial--but poorly observed--redshift range where galaxies appear to have assembled most of their stellar mass. This key process of galaxy evolution needs to be studied with IR data; we found that observations at shorter wavelengths appear to have missed a large fraction of the star-formation in galaxies, due to dust reddening. We will also obtain deep F110W and F160W images, to examine the space densities and morphologies of faint red galaxies. In addition to carrying out the public parallels, we will make the fully reduced and calibrated images and spectra available on-line, with some ground-based data for the deepest parallel fields included. ACS/WFC 9860 ESSENCE: Measuring the Dark Energy Equation of State The accelerating universe appears to be dominated by a dark energy with a significant negative pressure. The ratio of the pressure to density of this mysterious energy {its equation of state} is an observable which can differentiate between the proliferating candidate theories. We propose to estimate the dark energy equation of state by observing Type Ia supernovae at redshifts near z=0.7 with HST in concert with the on-going ESSENCE NOAO Survey program that is discovering and studying supernovae between 0.3z0.8. We show that an interesting constraint on the equation of state can be made with supernovae observed at modest redshifts given the current knowledge of the matter density. We will follow 10 Type Ia supernovae discovered from the ground and passed to HST without disrupting its schedule. The full data set will constrain the equation of state to 10% and strictly limit the range of possible dark energy models. In keeping with the ESSENCE policy, th ese observations will available to the community immediately. ACS/HRC 9851 Host Galaxies of Reverberation-Mapped AGNs We propose to obtain unsaturated ACS high-resolution images of all reverberation-mapped active galactic nuclei in order to remove the point-like nuclear light from each image, thus yielding a "nucleus-free" image of the host galaxy. This will allow investigation of host-galaxy properties: our particular interest is determination of the host-galaxy starlight contribution to the reverberation mapping observations, which is necessary for accurate determination of the relationship between the AGN continuum flux and the size of the broad Balmer-line emitting region of AGNs. Because this relationship is used to estimate black-hole masses of large samples of distant AGNs, correct determination of the slope of this relationship is critically important. ACS 9831 Multiplicity among brown dwarfs in the Pleiades cluster We have compiled a sample of 32 confirmed brown dwarfs in the Pleiades cluster. We propose to observe this sample with HST/ACS in SNAPSHOT mode in order to search for very low mass multiple systems. Our goals a 1} to determine the occurrence and frequency of binary systems among substellar objects, which hold important clues to the formation and evolution mechanism{s} of ultracool and brown dwarfs, 2} to get an estimate of the Initial Mass Function {IMF} at very low masses, which is still unknown and very much needed to be corrected for binarity, 3} to compare the distribution of multiple systems in young open clusters and in the field. NIC3/ACS/HRC/WFC 9803 Deep NICMOS Images of the UDF The ACS Ultra Deep Field {UDF} images will greatly enhance the rich suite of deep multi-wavelength images in the Chandra Deep Field South {CDF--S}. We propose to complete the image set with deep near-IR NICMOS images at 1.1 and 1.6 microns over a significant fraction of the UDF, providing a critical link between the HST ACS and SIRTF observations. The timely addition of the near-IR images ensures that investigators will have images that span the spectrum from X-ray to far IR. In recognition of the value of the near IR images this proposal is submitted as a Treasury proposal with no proprietary period. The proposal team will deliver science quality images, mosaiced images covering 4.9 sq arc min, and a photometric catalog complete to an AB mag of 28.2 in both the F110W and F160W filters. The program also delivers a parallel extremely deep ACS field, 8' away, that reaches to within 0.6 mag of the UDF in the same filters as the UDF. The scientific program of the proposal team focuses on the star formation history of the universe, evolved galaxies at high redshift, galaxies at the epoch of reionization, and the redshift evolution of AGNs and ULIRGs. The HDF-N is currently the only field with spatially-coincident deep HST imaging in both the optical and near-IR. The small size of the HDF-N means that large scale structure is the dominant error in the results from the HDF-N. Providing observations in a field that is spatially uncorrelated is critically important. The UDF/CDF-S fulfills that goal. The depth of the UDF ACS imaging, and the wealth of Great Observatory and ground based observations in the CDF-S, make these NICMOS observations uniquely valuable. An extraordinarily rich array of science opportunities await the community from the NICMOS UDF data. NIC2 9801 Are OH/IR Stars the Youngest post-AGB stars? A NICMOS Imaging Survey Essentially all well-characterized preplanetary nebulae {PPNe}-- objects in transition between the AGB and planetary nebula evolutionary phases - are bipolar, whereas the mass-loss envelopes of AGB stars are strikingly spherical. In order to understand the processes leading to bipolar mass-ejection, we need to know at what stage of stellar evolution does bipolarity in the mass-loss first manifest itself. We have recently hypothesized that most OH/IR stars {evolved mass- losing stars with OH maser emission} are very young PPNe. We are conducting a multiwavelength survey program of imaging and spectroscopic observations of such objects, using a large, morphologically unbiased sample selected using IRAS 12-to-25 micron colors. Our ongoing HST/SNAP imaging survey of the optically bright half of this sample with WFPC2 and ACS is highly successful: 19/32 objects observed are extended with bipolar/multipolar shapes {remaining objects are unresolved}. Slightly more than 50% of our sample are optically too faint or undetected but have strong near-IR counterparts -- we therefore propose a NICMOS SNAPshot imaging survey of these optically-faint OH/IR stars. These observations are crucial for determining how and when the bipolar geometry asserts itself. The results from our NICMOS survey {together with the WFPC2/ACS survey} will allow us to draw general conclusions about the onset of bipolar mass-ejection during late stellar evolution. Our complementary program of interferometric mapping of the OH maser emission in our sources is yielding kinematic information with spatial resolution comparable to that in the HST images. The HST/radio data will provide crucial input for theories of post-AGB stellar evolution. In addition, these data will also indicate whether the multiple concentric rings, "searchlight beams'', and truncated equatorial disks recently discovered with HST in a few PPNe, are common or rare phenomena. STIS 9786 The Next Generation Spectral Library We propose to continue the Cycle 10 snapshot program to produce a Next Generation Spectral Library of 600 stars for use in modeling the integrated light of galaxies and clusters. This program is using the low dispersion UV and optical gratings of STIS. The library will be roughly equally divided among four metallicities, very low {[Fe/H] lt -1.5}, low {[Fe/H]-1.5 to -0.5}, near-solar {[Fe/H] -0.3 to 0.1}, and super-solar {[Fe/H] gt 0.2}, well-sampling the entire HR-diagram in each bin. Such a library will surpass all extant compilations and have lasting archival value, well into the Next Generation Space Telescope era. Because of the universal utility and community-broad nature of this venture, we waive the entire proprietary period. ACS/WFC 9777 The environment of QSOs at the reionization epoch Our goal is to elucidate the role of QSOs and galaxies at the tail end of reionization by identifying z~6 galaxies near SDSS z6 QSOs through their red i-z colors. A similar technique was used by the SDSS to identify the QSOs themselves. Based on our understanding of the growth of structure in the Universe and on observations at z ~= 4, we expect z~6 QSOs to be associated to the high peaks in the matter density distribution. Therefore, they should be surrounded by an excess of objects - as compared to random fields - unless the ionizing radiation from the QSOs themselves is inhibiting star formation. We will concentrate on 5 QSOs discovered by the SDSS at z~6 and spend 7 orbits with ACS on each of the QSO fields {2.5 in F775W - i - and 4.5 in F850LP - z}, for a total of 35 orbits. The exposures are optimized for the detection of objects with i-z 2. The reference properties of the field population will be provided by GOODS which is reaching the same depth. The proposed observations will be capable of revealing the dominant effect between galaxy suppression by the QSO ionizing flux and number density excess due to clustering. We will test whether the balance between suppression and enhancement evolves with redshift. We will also be able to estimate for these fields the ionizing continuum contribution by galaxies and compare it with that of the QSOs. If galaxies are found to be comparably important to QSOs in these selected fields, the idea that hydrogen reionization is primarily due to stellar radiation would be significantly strengthened. ACS/HRC 9747 An Imaging Survey of the Statistical Frequency of Binaries Among Exceptionally-Young Dynamical Families in the Main Asteroid Belt We propose an ambitious SNAPSHOT program to determine the frequency of binaries among two very young asteroid families in the Main Belt, with potentially profound implications. These families {of C- and S-type} have recently been discovered {Nesvorny et al. 2002, Nature 417, 720}, through dynamical modeling, to have been formed at 5.8 MY and 8.3 MY ago in catastrophic impact events. This is the first time such precise and young ages have been assigned to a family. Main-belt binaries are almost certainly produced by collisions, and we would expect a young family to have a significantly higher frequency of binaries than the background, because they may not yet have been destroyed by impact or longer-term gravitational instabilities. In fact, one of the prime observables from such an event should be the propensity for satellites. This is the best way that new numerical models for binary production by collisions {motivated largely by our ground-based discoveries of satellites among larger asteroids}, can be validated and calibrated. HST is the only facility that can be used to search for binaries among such faint objects {V17.5}. We will also measure two control clusters, one being an "old" family, and the other a collection of background asteroids that do not have a family association, and further compare with our determined value for the frequency of large main-belt binaries {2%}. We request visits to 180 targets, using ACS/HRC. ACS/HRC 9721 The Kinematics and Dynamics of the Material Surrounding Eta Carinae We propose a series of observations using ACS/HRC that will perform astrometric measurements of the ejecta around eta Car. We will observe ejecta in three distinct regions: the inner {characterized by the close-in debris such as the Weigelt blobs}, the intermediate {primarily the equatorial disk}, and the outer {the homunculus and the North and South Jet structures}. These observations will provide second and third epoch measurements vs. previous WFPC2 data. The resultant significantly increased temporal baseline {with corresponding decreases in proper motion, date of origin and 3D orientation errors} will allow for the detection of acceleration and non-radial motion in the ejecta, testing the canonical hypothesis of ballistic motion. A secondary goal of the observations will be to compare the HRC measurements with concurrent Cycle 12 WFPC2 measurements taken by other observers {who have indicated they will release their data immediately} is order to provide a calibration link between the WFPC2 and HRC astrometric frames. Our proposed HRC observations will require three HST orbits. WFPC2 9712 Pure Parallel Near-UV Observations with WFPC2 within High-Latitude ACS Survey Fields In anticipation of the allocation of ACS high-latitude imaging survey{s}, we request a modification of the default pure parallel program for those WFPC2 parallels that fall within the ACS survey field. Rather than duplicate the red bands which will be done much better with ACS, we propose to observe in the near-ultraviolet F300W filter. These data will enable study of the rest-frame ultraviolet morphology of galaxies at 0z1. We will determine the morphological k-correction, and the location of star formation within galaxies, using a sample that is likely to be nearly complete with multi-wavelength photometry and spectroscopic redshifts. The results can be used to interpret observations of higher redshift galaxies by ACS. WFPC2 9709 POMS Test Proposal: WFII parallel archive proposal This is the generic target version of the WFPC2 Archival Pure Parallel program. The program will be used to take parallel images of random areas of the sky, following the recommendations of the 2002 Parallels Working Group. GO 9406 GD 552: The Oldest Cataclysmic Variable A terrible puzzle has long afflicted our understanding of the evolution of cataclysmic variables {CVs}. Angular momentum loss should grind the binaries down to orbital periods near 1.3 hr in 2 -- 4 Gyr, and then slowly drive them apart again. Most CVs should therefore have undergone ``period bounce" long ago, and be evolving towards longer period, with secondaries 0.1 M_odot. However, not a single post-bounce CV has been conclusively identified. Where are the old CVs hiding? They should be hard to find since they're probably faint intrinsically, and because their accretion rates may be too low to trigger dwarf-nova eruptions. One, and only one, good candidate appears in the Lowell proper-motion lists. This is GD 552: noneruptive, possessing a light secondary, and probably the least luminous CV yet found {M_V ~ +12.5}. An accurate FGS parallax will establish whether this object {clearly very nearby} signifies a large population of very old CVs. A 1200 -- 10000 Angstrom spectrum would likely represent a pure steady-state low-dot M disk {the only one known}, and the FUV region would provide a measurement of T_ eff in a white dwarf long after eruptive heating episodes have stopped. The UV observation obviously requires HST, and efforts to measure the parallax from the ground are thwarted by a background star 0^ .7 distant. 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. WFPC2 10082 POMS Test Proposal: WFII backup parallel archive proposal This is a POMS test proposal designed to simulate scientific plans WFPC2 10075 WFPC2 CYCLE 12 Intflat and Viflat Sweeps and Filter Rotation Anomaly Monitor Using intflat observations, this WFPC2 proposal is designed to monitor the pixel-to-pixel flatfield response and provide a linearity check. The intflat sequences, to be done once during the year, are similar to those from the Cycle 11 program 9597. The images will provide a backup database in the event of complete failure of the visflat lamp as well as allow monitoring of the gain ratios. The sweep is a complete set of internal flats, cycling through both shutter blades and both gains. The linearity test consists of a series of intflats in F555W, in each gain and each shutter. As in Cycle 11, we plan to continue to take extra visflat, intflat, and earthflat exposures to test the repeatability of filter wheel motions. WFPC2 10069 WFPC2 CYCLE 12 Supplemental Darks, Part 1/3 This dark calibration program obtains 3 dark frames every day to provide data for monitoring and characterizing the evolution of hot pixels. WFPC2 10067 WFPC2 Cycle 12 Decontaminations and Associated Observations This proposal is for the monthly WFPC2 decons. Also included are instrument monitors tied to decons: photometric stability check, focus monitor, pre- and post-decon internals {bias, intflats, kspots, & darks}, UV throughput check, VISFLAT sweep, and internal UV flat check. ACS/WFC 10055 ACS Polarization Calibration This proposal aims to address several specific issues for the polarization calibration: {1} variations in calibration with position on the detector {field dependence}, {2} dependence on telescope roll-angle relative to the target, {3} orientation of the polarizer axes, and {4} geometric distortion contributed by the polarizers. ACS/HRC/WFC 10042 CCD Daily Monitor This program consists of basic tests to monitor, the read noise, the development of hot pixels and test for any source of noise in ACS CCD detectors. This programme will be executed once a day for the entire lifetime of ACS. STIS/CCD 10019 CCD Bias Monitor - Part 1 Monitor the bias in the 1x1, 1x2, 2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up high-S/N superbiases and track the evolution of hot columns. STIS/CCD 10017 CCD Dark Monitor-Part 1 Monitor the darks for the STIS CCD. WFPC2/ACS/HRC/WFC 10013 Focus Monitor The focus of HST is measured from WFPC2/PC and ACS/HRC images of stars. Multiple exposures are taken in parallel over an orbit to determine the influence of breathing on the derived mean focus. Observations are taken of clusters with suitable orientations to ensure stars appear in all fields. STIS/CCD 10000 STIS Pure Parallel Imaging Program: Cycle 12 This is the default archival pure parallel program for STIS during cycle 12. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9208: GS Acquisition (2,1,1) @ 320/16:41:35Z ended in FL backup (2,0,2) due to SSLE on FGS 1 @ 320/16:45:08Z. GS Reacquisition @ 320/18/25:50Z also ended in FL backup. Under investigation. COMPLETED OPS REQs: NONE OPS NOTES EXECUTED: 1173-0 Change Limits MAMA1 Threshold Voltage @ 318/10:20z 1135-2 Battery Pressures Ground Limits @ 318/21:30z 1174-0 Adjust Error Count limit @ 320/05:50z 1173-0 Change Limits MAMA1 Threshold Voltage @ 321/05:33z SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 24 24 FGS REacq 20 20 FHST Update 51 50 319/15:29:01z 2rd FM failed. LOSS of LOCK SIGNIFICANT EVENTS: None |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Monitoring NASA Daily ISS Report | JimO | Space Station | 2 | June 1st 04 10:33 PM |
JimO Speaks on 'Daily Planet' re Hubble | JimO | Policy | 0 | February 11th 04 10:53 PM |
Spirit's daily activities schedule? | Matti Anttila | Policy | 0 | January 15th 04 08:39 AM |
best site for daily schedule of rover activity? | bob | History | 2 | January 5th 04 12:16 PM |
Investor's Business Daily: Rethinking NASA | dougk | Policy | 1 | August 28th 03 12:07 AM |