#1
|
|||
|
|||
Daily 3492
HUBBLE SPACE TELESCOPE
DAILY REPORT # 3492 PERIOD COVERED: DOY 321 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. 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. ACS/HRC/WFC 9796 Observations of Intermediate Mass Black Hole Candidate Ultra-Luminous X-ray Sources Ultra-luminous X-ray {ULX} sources are off-nuclear point sources in nearby normal galaxies. Variability observed on the timescale of days, weeks, and years signals that ULXS are accreting sources, likely harboring black holes. However, the observed X-ray luminosity of these systems far exceeds the Eddington limit for a 10 Msun black hole; some ULXs may be intermediate mass black holes. The identification and study of optical counterparts with HST will be central to better understanding these objects. We propose to obtain deep U-B-V-I exposures of 4 extremely bright ULXs in nearby spirals: NGC 1313 X-1 and X-2, M81 X-9 {Holmberg II X-1}, and M74 X-1. Each has a 0.5'' Chandra position, and X-ray luminosity and spectral characteristics consistent with expectations for intermediate mass black holes. We will use the colors we obtain, the magnitudes we measure, and any source variability {also, correlated optical-X-ray variability from simultaneous Chandra snapshots} to constrain the nature of the donor stars and the black holes {10 Msun or 100-1000 Msun}, and the formation and evolution scenarios for each system. ACS/WFC 9744 HST Imaging of Gravitational Lenses Gravitational lenses offer unique opportunities to study cosmology, dark matter, galactic structure, galaxy evolution and quasar host galaxies. They are also the only sample of galaxies selected based on their mass rather than their luminosity or surface brightness. While gravitational lenses can be discovered with ground-based optical and radio observations, converting them into astrophysical tools requires HST. HST has demonstrated that it is the only telescope that can in each case precisely locate the lens galaxy, measure its luminosity, color and structure, and search for lensed images of the source host galaxy given the typical image separations of ~1''. We will obtain ACS/WFC V and I images and NICMOS H images of 21 new lenses never observed by HST and NICMOS H images of 16 lenses never observed by HST in the IR. As in previous cycles, we request that the data be made public immediately. ACS/WFC 9765 The Dusty ISM Substructure in Nearby Spiral Galaxies We propose an ACS V&I imaging snapshot survey of all nearby edge-on spiral galaxies in order to measure the small scale structures in their dust extinction down to the 10pc scale. Dust and molecular gas are tightly coupled and therefore HST high resolution reddening maps can reveal information about the cold ISM phase on a scale inaccessible from the groundby any other means. We have recently discovered a sudden change in dust lane properties using ground-based data; all galaxies with rotation speeds in access of 120km/s show dust lanes, but none of the slower rotators does. This transition may be caused by a sudden change in the state of the multiphase ISM, and HST resolution imaging is needed to fully quantify this effect. Analysis will consist of full radiative transfer modeling of dust extinction with realistic, fractal like substructure and power spectrum analysis of the structure from the global to the 10pc scale. By observing a sample of galaxies with a range in structural parameters we can quantify how the cold ISM structure changes as function of radius, rotation speed, local surface density, et cetera. This information is duly needed with SIRTF soon providing a wealth of information on dust absorption, but lacking the resolution to determine the small scale distribution of the dust. ACS/WFC 9991 The Orbit of a Newly Discovered Transneptunian Binary We have recently discovered a binary companion to the transneptunian object {TNO} 1999 RZ253. We are requesting rapid followup observations during cycle 12 to make observations sufficient for a preliminary characterization of the orbital period, semimajor axis, eccentricity, and inclination. In particular, it is urgent to determine if this object is a candidate for observable mutual events in the near future, a possibility that would greatly add to its scientific interest. The study of TNBs is in a stage of explosive growth, fueled in large part by the capabilities of HST that we seek to exploit. ACS/WFPC2 9488 Cosmic Shear - with ACS Pure Parallel Observations The ACS, with greater sensitivity and sky coverage, will extend our ability to measure the weak gravitational lensing of galaxy images caused by the large scale distribution of dark matter. We propose to use the ACS in pure parallel {non- proprietary} mode, following the guidelines of the ACS Default Pure Parallel Program. Using the HST Medium Deep Survey WFPC2 database we have measured cosmic shear at arc-min angular scales. The MDS image parameters, in particular the galaxy orientations and axis ratios, are such that any residual corrections due to errors in the PSF or jitter are much smaller than the measured signal. This situation is in stark contrast with ground-based observations. We have also developed a statistical analysis procedure to derive unbiased estimates of cosmic shear from a large number of fields, each of which has a very small number of galaxies. We have therefore set the stage for measurements with the ACS at fainter apparent magnitudes and smaller, 10 arc-second scales corresponding to larger cosmological distances. We will adapt existing MDS WFPC2 maximum likelihood galaxy image analysis algorithms to work with the ACS. The analysis would also yield an online database similar to that in archive.stsci.edu/mds/ FGS 9879 An Astrometric Calibration of the Cepheid Period-Luminosity Relation We propose to measure the parallaxes of 10 Galactic Cepheid variables. There is no other instrument on or off the earth that can consistently deliver HST FGS level of precision for critical parallaxes. When these parallaxes {with 1-sigma precisions of 10% or better} are added to our recent HST FGS parallax determination of delta Cep {Benedict et al 2002}, we anticipate determining the Period-Luminosity relation zero point with a 0.03 mag precision. In addition to permitting the test of assumptions that enter into other Cepheid distance determination techniques, this calibration will reintroduce Galactic Cepheids as a fundamental step in the extragalactic distance scale ladder. A Period-Luminosity relation derived from solar metallicity Cepheids can be applied directly to extragalactic solar metallicity Cepheids, removing the need to bridge with the Large Magellanic Cloud and its associated metallicity complications. 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 excellentmeasure 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. NIC2 9726 A NICMOS search for obscured supernovae in starburst galaxies Recent near-IR monitoring campaigns were successful in detecting obscured supernovae {SNe} in starburst galaxies. The inferred SN rate is much higher than that obtained in previous optical campaigns, but it is still significantly lower than expected by the high level star formation of these systems. One possible explanation for the shortage of SNe is that most of them occur in the nuclear region, where the limited angular resolution of groundbased observations prevents their detection. We propose NICMOS SNAP observations of a sample of starburst galaxies already observed once by NICMOS, with the goal of exploiting its sensitivity and angular resolution to detect nuclear obscured SNe which might have been missed by groundbased surveys. These observation will allow to assess the real SN rate in starbust galaxies and deliver a sample of SN occurring in the extreme environment of galactic nuclei. We expect to detect more than 55 SNe {if the whole sample is observed}. If the number of SNe detected in the program is much lower than expected it would prompt for a revision of our understanding of the relation between the star formation rate and the SN rate. NIC3 9878 The Age and Mass Function of the Intermediate Age Globular Cluster System of NGC 4365 We propose to obtain deep H-band photometry of the globular cluster system of the elliptical galaxy NGC 4365, which has previously been shown from shallow data to have a significant population of intermediate-age globular clusters. These data will allow us to constrain the luminosity and mass function of the intermediate-aged globular cluster system. This is a critical step in understanding the relationship between the young dense star cluster systems observed in galaxy mergers and starbursts, which have a power-law mass functions, and well known old, globular cluster systems, which have a lognormal mass functions. Specifically, the large intermediate-age cluster population in NGC 4365 provides the best case to test whether the power-law mass function of young systems evolves into a lognormal with the properties of old globular cluster systems. Dynamical models have long suggested such an evolution of a power-law mass function to a roughly log-normal one but there is no clear observational evidence yet in elliptical galaxies for steps along this process. Our proposed study of the intermediate-age cluster system of NGC 4365 will provide us with the fundamental information needed to conclusively establish the relationship between young and old globular cluster systems. NICMOS 8790 NICMOS Post-SAA calibration - CR Persistence Part 1. 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. S/C/NIC1/NIC3 9994 NICMOS Focus Stability The purpose of this activity is to determine if the best focus determined in SMOV is stable. This program will execute in approximately one month intervals starting about 1 month after the last execution of proposal 8980. 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. STIS/CCD 10000 STIS Pure Parallel Imaging Program: Cycle 12 This is the default archival pure parallel program for STIS during cycle 12. STIS/CCD 10017 CCD Dark Monitor-Part 1 Monitor the darks for the STIS CCD. 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/MA1 10034 Cycle 12 MAMA Dark Monitor This test performs the routine monitoring of the MAMA detector dark noise. This proposal will provide the primary means of checking on health of the MAMA detectors systems through frequent monitoring of the background count rate. The purpose is to look for evidence of change in dark indicative of detector problem developing. WFPC2 10068 WFPC2 CYCLE 12 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. 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 10072 WFPC2 CYCLE 12 INTERNAL MONITOR This calibration proposal is the Cycle 12 routine internal monitor for WFPC2, to be run weekly to monitor the health of the cameras. A variety of internal exposures are obtained in order to provide a monitor of the integrity of the CCD camera electronics in both bays {gain 7 and gain 15}, a test for quantum efficiency in the CCDs, and a monitor for possible buildup of contaminants on the CCD windows. 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 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. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: NONE OPS NOTES EXECUTED: NONE SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 10 10 FGS REacq 06 06 FHST Update 21 21 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 |