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Daily 3813
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3813 PERIOD COVERED: DOY 68 OBSERVATIONS SCHEDULED ACS/HRC 10255 A Never Before Explored Phase Space: Resolving Close White Dwarf / Red Dwarf Binaries We propose an ACS Snapshot imaging survey to resolve a well-defined sample of highly probable white dwarf plus red dwarf close binaries. These candidates were selected from a search for white dwarfs with infrared excess from the 2MASS database. They represent unresolved systems {separations less than approximately 2" in the 2MASS images} and are distributed over the whole sky. Our HST+ACS observations will be sensitive to a separation range {1-20 AU} never before probed by any means. The proposed study will be the first empirical test of binary star parameters in the post-AGB phase, and cannot be accomplished from the ground. By resolving as few as 20 of our ~100 targets with HST, we will be able to characterize the distribution of orbital semi- major axes and secondary star masses. 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 10117 The Co-Evolution of Star Formation and Powerful Radio Activity in Galaxies We will carry out a STIS/NUV-MAMA snapshot imaging survey of the most compact powerful radio galaxies, the Gigahertz Peaked Spectrum {GPS} sources and Compact Steep Spectrum {CSS} sources. These objects are as powerful as the large radio doubles but are much smaller {and younger} and are crucial to our understanding not only of how radio-loud active galactic nuclei {AGN} form and evolve, but also what role they play in the evolution of galaxies. A very direct and robust way to address these issues is by high resolution imaging of the host galaxies of these sources in the UV. This has never been done before for a sample of these very compact sources, since previous HST/UV imaging programs have focussed on the larger radio galaxies. The UV emission can provide crucial information about any recent star formation that may have occurred as a result of ongoing accretion, mergers, interactions, or triggering by the radio source. By comparing the starburst properties of GPS, CSS, and large scale radio sources, we will be able to constrain the evolution of massive star formation as a function of the relative age of the radio source. {Note, due to the failure of STIS, these observations will be carried out using the ACS/HRC}. ACS/HRC/WFC 10214 ACS/HRC imaging of two very bright ultra-luminous X-ray sources {ULXs} We propose broad- and narrow-band ACS/HRC imaging of two very bright ultraluminous X-ray sources {ULXs} in NGC 4559. Our main objectives a to identify the optical counterparts; to determine their masses and evolutionary stages; to determine the nature of mass transfer in the ULX systems; to determine the properties of the stellar population in the ULX fields {eg, metal abundance, age}. With these observations, integrated with our Chandra, XMM-Newton, HST/WFPC2 and CHFT data, we will test the models for the nature and mechanisms of formation of the accreting black holes in ULXs. Moreover, one of the two ULXs is in a peculiar star-forming complex: we have suggested that it is an expanding wave of star-formation triggered by a dwarf galaxy plunging through the outer disk of NGC 4559. The ACS observation will also allow us to test this hypothesis. ACS/HRC/WFC 10367 ACS CCDs daily monitor- cycle 13 - part 1 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/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/WFC/NIC2 10189 PANS-Probing Acceleration Now with Supernovae Type Ia supernovae {SNe Ia} provide the most direct evidence for an accelerating Universe, a result widely attributed to dark energy. Using HST in Cycle 11 we extended the Hubble diagram with 6 of the 7 highest-redshift SNe Ia known, all at z1.25, providing conclusive evidence of an earlier epoch of cosmic deceleration. The full sample of 16 new SNe Ia match the cosmic concordance model and are inconsistent with a simple model of evolution or dust as alternatives to dark energy. Understanding dark energy may be the biggest current challenge to cosmology and particle physics. To understand the nature of dark energy, we seek to measure its two most fundamental properties: its evolution {i.e., dw/dz}, and its recent equation of state {i.e., w{z=0}}. SNe Ia at z1, beyond the reach of the ground but squarely within the reach of HST with ACS, are crucial to break the degeneracy in the measurements of these two basic aspects of dark energy. The SNe Ia we have discovered and measured with HST in Cycle 11, now double the precision of our knowledge of both properties. Here we propose to quadruple the sample of SNe Ia at z1 in the next two cycles, complementing on-going surveys from the ground at z1, and again doubling the precision of dark energy constraints. Should the current best fit model prove to be the correct one, the precision expected from the current proposal will suffice to rule out a cosmological constant at the 99% confidence level. Whatever the result, these objects will provide the basis with which to extend our empirical knowledge of this newly discovered and dominant component of the Universe, and will remain one of the most significant legacies of HST. In addition, our survey and follow-up data will greatly enhance the value of the archival data within the target Treasury fields for galaxy studies. NIC1 10415 A Proper Motion Study of the Ionized Gas in the Vicinity of the Galactic Center Black Hole The Galactic Center's distance of only 8 kpc provides a unique opportunity to study the interaction of a supermassive black hole with its environment at a level of detail not possible for other galaxies. We propose to observe the inner parsec of the Galaxy in the Paschen alpha line with Camera 1 of NICMOS in order to study the kinematics of ionized gas in the vicinity of the supermassive black hole coincident with Sgr A*. Our previous GO program 7842 yielded detailed Pa alpha images revealing complex, filamentary structure at 0.16 arcsec {0.006 pc} resolution. However, proper motions could not be robustly derived from that data set due to the fact that the two epochs were spaced only 7 months apart. In order to follow up on preliminary results showing evidence for high proper motions within 2'' of Sgr A* and to characterize the rest of the central parsec, we propose to obtain two additional epochs within Cycle 13 so that the dataset will comprise independent measurements of the proper motions ranging from intervals of 5 months to 7 years, with the 7 year interval giving a 1 sigma accuracy of 45 km/s. These will be combined with existing radial velocity measurements to provide the first complete characterization of the kinematics of the ionized gas in the central parsec. This is crucial to interpreting the relative importance of gravitational forces, stellar winds, and possible accretion onto or outflow from the black hole. These observations may possibly lead to the first direct observation of gas in the process of accretion {or ejection via a jet} associated with the Galactic Center black hole. The kinematics of the gas may also imply that accretion may be inhibited, and this could explain the low luminosity of Sgr A*. 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. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) None COMPLETED OPS REQs: 17391-3 NICMOS CS FSW v4.0Ce Installation @ 068/2255z 17398-0 NICMOS Interim Checksum @ 068/1310z, 068/2255z OPS NOTES EXECUTED: None SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 08 08 FGS Reacq 07 07 FHST Update 14 14 LOSS of LOCK SIGNIFICANT EVENTS: NICMOS CS Flight Software (FSW) Load: Steps 22 through 41 of Ops Request 17391 were completed successfully on 068/2300. This completed the load of NICMOS CS FSW to EEPROM. |
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