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Daily 3589
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3589 PERIOD COVERED: DOYs 100-102 OBSERVATIONS SCHEDULED FGS 9888 Trigonometric Calibration of the Period- Luminosity Relations for Fundamental and First-Overtone Galactic Cepheids Cepheids are the primary distance indicators for the extragalactic distance scale and the Hubble constant. The Hubble Constant Key Project set the zero-point for their Cepheid distance scale by adopting a distance to the LMC, averaged over a variety of techniques. However, different methods give an LMC distance modulus ranging from 18.1 to 18.8, and the uncertainty in the Cepheid zero-point is now the largest contributor to the error budget for H_0. Moreover, the low metallicity of the LMC raises additional concerns, since the PL relation probably depends on metallicity. The zero-point can be determined from Hipparcos parallaxes of Galactic Cepheids out to several hundred parsecs, but with a typical parallax error of 0.5-1 mas, the Hipparcos error bars are uncomfortably large for this demanding application. By contrast, HST's FGS1R interferometer can achieve astrometric accuracy of 0.2 mas. We propose to use FGS1R to determine trigonometric parallaxes for a sample of 9 nearby Cepheids, including both fundamental {F} and first-overtone {FO} pulsators. We show that the improvement in the PL relations for F and FO Cepheids will be dramatic. We will determine the PL slopes from our nearby solar- metallicity sample alone, without recourse to nearby galaxies and the issue of [Fe/H] dependence. The zero-point will be determined robustly to about 0.05 mag, based on accurate, purely geometrical measurements. All of this can be achieved in the next few years with HST, without having to wait for the technically demanding and risky SIM and GAIA missions well into the next decade. STIS/CCD/MA2 9886 Boron in F Stars in the Hyades - Insights into the Li-Be Dip Dramatic deficiencies of Li in the mid-F stars of the Hyades were discovered by Boesgaard and Tripicco in 1986. Using ultraviolet, high-resolution spectra from the Keck 10-m telescope, Boesgaard and King have just discovered the corresponding deficiencies in Be in the same narrow temperature region in the Hyades. We propose a precision investigation into the B abundance in the Hyades F stars to ascertain if there is a B dip. Boron can only be observed with HST and we plan to use the resonance line of B I at 2497A. Each of these three light elements is destroyed inside stars, but each has a different threshold temperatu 2.5 x 10^6, 3.5 x 10^6, and 5 x 10^6 K for Li, Be, and B respectively. Consequently, these elements survive to increasingly greater depths in a star and their surface abundances act as a report on the depth and thoroughness of mixing in the star. The mixing mechanism in F stars is slow mixing, but not straight convective mixing. These observations will help determine the nature of the mixing mechanism{s}, and the connection to stellar rotation. The abundance of *all three* light elements in a cluster ofknown age and metallicity provides the necessary information to discern the internal stellar processes. This mixing must be occurring in other stars of this mass range {~10-25% more massive than the sun} and can best be studied in a cluster of stars of common origin and known characteristics. The Hyades cluster at 7 x 10^8 yr is close enough to contain stars bright enough for this investigation. FGS 9879 An Astrometric Calibration of the Cepheid Period-Luminosity Relation We propose to measure the parallaxes of 10 Galactic Cepheid variables. 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. STIS/CCD/MA1 9874 Probing IGM Phases, Metals, and the Cosmic Web with New SDSS QSOs We propose STIS G140L SNAPSHOT observations of 100 new z 1 QSOs from the Sloan Digital Sky Survey for studies of the IGM. These targets will be chosen to simultaneously maximize IGM pathlength and to form closely spaced groups of 2-8 QSO sightlines within 1 h^-1 Mpc of a foreground galaxy. These observations will, in the long term, provide a rich database of target QSOs for detailed study by COS of the IGM phases, metallicity, and relationship to the large scale structure. In the near term, these observations will detect up to 10 Lyman alpha clouds with N_HI 10^14 and 3 clouds with N_HI 10^15, per target. Thus they will provide an immediate test of filamentary structure in the "cosmic web" within 1 h^-1 Mpc of galaxies. We ask for 22 minute exposures for each target with STIS/G140L to obtain S/N = 5-16 for these V = 16 - 18 QSOs. These observations will be sensitive to Lyman alpha equivalent widths ranging from 300 mA for the brighter sources to 600 mA at the fainter end. These targets represent a Deltaz pathlength of 17 {at 50% yield}, with Deltaz = 10 in the range where Lya, Lyb, and O VI lie in the HST band. These observations will also refine predictions of the FUV flux of QSOs based on the larger SDSS sample and will estimate the degree to which such factors as intrinsic and Galactic extinction, variability, and intervening absorption can be controlled. If successful, this technique could make UV-prequalification SNAPs of QSOs obsolete, at a significant savings of HST time. Our observations lie at the median duration for SNAPs, and in the range most likely to be executed. Our program accomplishes both near- and long-term goals at a relatively low investment of time, and thus is ideally suited for a SNAP proposal. To ensure maximum scientific return for our own purposes and for additional science {HVCs, Galactic halo} we waive the right to a proprietary data period. ACS/WFC/WFPC2 9822 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. STIS/CCD/MA1 9818 Reverberation Mapping of the Least Luminous Seyfert 1 Galaxy NGC 4395 We propose to make a short UV and optical reverberation mapping monitoring of NGC~4395, by far the least luminous Seyfert 1 galaxy known {M_B~ -10}, where the Broad Line Region {BLR} is most likely between a fraction of a light hour to a few light hours across. This program will: 1. extend by a factor of ~100 the range of R_BLR probed by RM, 2. allow to test models for AGN continuum emission and BLR structure at very low L and M_BH. 3. provide significantly more reliable estimates of its M_BH than currently available, 4. allow to probe the M_BH-sigma_* relation in AGN at very low M_BH, which cannot be probed by other methods. Existing archival FOS observations indicate significant {up to 30-40%} line and continuum variations within one orbit, suggesting that the proposed RM is likely to succeed. The unusually small R_BLR in NGC 4395 implies that RM can be performed here at only a fraction of the cost required in typical AGN. ACS/WFC 9788 A Narrow-band Snapshot Survey of Nearby Galaxies We propose to use ACS/WFC to conduct the first comprehensive HST narrow-band {H-alpha + [N II]} imaging survey of the central regions of nearby bulge-dominated disk {S0 to Sbc} galaxies. This survey will cover, at high angular resolution extending over a large field, an unprecedented number of galaxies representing many different environments. It will have important applications for many astrophysical problems of current interest, and it will be an invaluable addition to the HST legacy. The observations will be conducted in snapshot mode, drawing targets from a complete sample of 145 galaxies selected from the Palomar spectroscopic survey of nearby galaxies. Our group will use the data for two primary applications. First, we will search for nuclear emission-line disks suitable for future kinematic measurements with STIS, in order to better constrain the recently discovered relations between black hole mass and bulge properties. Preliminary imaging of the type proposed here must be done, sooner or later, if we are to make progress in this exciting new field. Second, we will investigate a number of issues related to extragalactic star formation. Specifically, we will systematically characterize the properties of H II regions and super star clusters on all galactic scales, from circumnuclear regions to the large-scale disk. 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/HRC/WFC 9781 Galaxy Evolution in Action : The Detailed Morphology of Post-Starburst Galaxy If galaxies evolve morphologically, then some should be in transition between late and early types. One proposed evolutionary mechanism is a galaxy-galaxy merger, but evolved merger products are difficult to find. Fortunately, spectroscopic surveys have now uncovered large numbers of E+A galaxies, a class of objects whose post-starburst spectra, current lack of HI gas, and pressure-supported kinematics suggest that they are the missing panel that connects the "Toomre sequence" of merging spirals with normal ellipticals and S0s. Our first HST observations of five of these galaxies are intriguing. We find a considerable range of tidally disturbed morphologies, an "E+A" fundamental plane, significant differences among the color gradients within 1 kpc {~0.8''}, and populations of bright, blue globular clusters. These initial results are difficult to interpret, however, because they are drawn from a small sample of galaxies whose very blue overall colors may have selected a particular evolutionary path of E+As. Here we propose for ACS imaging of the remaining 15 E+As from the Las Campanas Redshift Survey to probe the full range of E+A properties. The proposed observations will allow us to 1} determine what fraction of the interactions that lead to E+As destroy all disk-like structures {and therefore necessarily lead to elliptical formation}, 2} measure the inner color gradients and constrain the spatial distribution of stars produced as gas sinks to the center during a merger, and 3} determine whether these interactions produce globular clusters in the required numbers to account for the increased specific frequency of clusters in early-type galaxies. ACS/WFC/HRC 9771 The local Hubble flow and the density field within 6 Mpc Great progress has been made recently in accurate distance measurements of nearby galaxies beyond the Local Group based on the luminosity of the tip of the red giant branch {TRGB}. Over the last three years, snapshot surveys with HST have provided us with the TRGB distances for more than a hundred nearby galaxies obtained with an accuracy of about 10%. The local velocity field within 5 Mpc exhibits a significant anisotropy which disagrees with a spherical Virgo-centric flow. The local Hubble flow is very cold, with 1-D rms deviations of ~30 km/s. Cosmological simulations with Cold Dark Matter can only realize such low dispersions with a combination of a low mean density of matter and a substantial component with negative pressure. There may be a constraint on the equation of state w=-p/rho. Our observations will concentrate on 116 galaxies whose expected distances lie within 4 - 6 Mpc, allowing us to trace a Dark Matter distribution in the Local Volume with twice the information currently available. The program is a good one for SNAP mode because the order and rate that the observations are made are not very important, as long as there is good completion over several years. ACS/STIS 9451 ACS Imaging and STIS Spectroscopy of Binary Brown Dwarfs We have compiled a sample of 9 spatially resolved binary brown dwarfs {18 objects}, and now propose ACS imaging and STIS spectroscopic follow-up observations. While theoretical models on the interplay of chemical and physical processes governing brown dwarf atmospheres have reached a high level of sophistication, interpretation of observational data remains difficult. As brown dwarfs never stabilize themselves on the hydrogen main sequence, there is always an ambiguity between the temperature or luminosity of any brown dwarf and its mass or age. The individual components of brown dwarf binaries, however, are expected to be coeval and have the same underlying chemical composition. This provides crucial constraints on any model, thus greatly reducing the number of the free parameters. The aim is to obtain photometric and spectroscopic data to probe the physical and chemical properties of the brown dwarf atmospheres, as well as second epoch astrometric data to characterize th e orbital motion. The study will provide important feedback on theoretical model atmospheres and evolutionary tracks for brown dwarfs. As such, it will be an important step towards a better understanding of objects with spectral properties intermediate between those of giant planets and late-type stars. 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. S/C 10097 NICMOS Temperature Setpoint Darks NICMOS darks at different temperatures are needed to calibrate the software tool used to create synthetic darks. Synthetic darks are used during calibration. The temperatures of the NICMOS detectors will be adjusted by +0.5 to -1.0 K from the nominal operating temperature. Darks in each camera will be obtained at each of the temperature settings. At the end of the Proposal the NCS nominal setpoint temperature for the NICMOS detectors will be increased by 0.07 K for the cool season {routine seasonal adjustment}. WFPC2 10070 WFPC2 CYCLE 12 Supplemental Darks Part 2/3 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/HRC/WFC 10060 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 10050 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 coronographic monitoring is required to assess the changing position of the spots. ACS/HRC/WFC 10044 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}. STIS/CCD 10020 CCD Bias Monitor - Part 2 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 10018 CCD Dark Monitor-Part 2 Monitor the darks for the STIS CCD. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9371: Upon AOS @ 100/11:00:52Z, HST was operating in FL backup on FGS 1 only. No FGS flags were set. Further information after engineering recorder dump. Secondary FGS GS ID 0024400268 is the same star as in previous HSTAR 9370, primary GS ID is different from previous HSTAR. Under investigation. HSTAR 9372: GS Acquisition (2,1,1) @ 101/03:12:07Z ended in FL backup on FGS 2 due to SSLE on FGS 1 @ 101/03:15:09Z. GS Reacquisitions @ 101/04:31:22Z and 06:07:20Z also ended in FL backup on FGS 2. Under investigation. HSTAR 9373: CCS "G" String CCLIsp alarming due to process count of zero @ 103/05:20Z. Steve Brandenburg advised this is a known problem and requires a full string recycle. FOT recycled string, problem cleared. Under investigation. COMPLETED OPS REQs: None OPS NOTES EXECUTED: 0900-1 COMMAND PROBLEM @ 101/06:40:23z 0900-1 COMMAND PROBLEM @ 102/17:02:23z 0911-0 Limit Management During WFPC2 Decontamination (M001) @100/1941z 0911-0 Limit Management During WFPC2 Decontamination (M001) @101/0738z 1216-0 HST486 S/W Memory Dump (RAM) @ 102/2100z 1217-0 HST486 S/W Memory Dump (EEPROM) @ 103/0200z SCHEDULED SUCCESSFUL FAILURE TIMES FGS GSacq 25 25 FGS REacq 26 26 FHST Update 43 43 LOSS of LOCK SIGNIFICANT EVENTS: None |
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