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Daily 3826
HUBBLE SPACE TELESCOPE - Continuing to collect World Class Science
DAILY REPORT # 3826 PERIOD COVERED: DOY 87 OBSERVATIONS SCHEDULED ACS/HRC 10185 When does Bipolarity Impose itself on the Extreme Mass Outflows from AGB Stars? An ACS SNAPshot 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? Our previous SNAPshot surveys of a PPNe sample {with ACS & NICMOS} show that roughly half our targets observed are resolved, with well-defined bipolar or multipolar morphologies. Spectroscopic surveys of our sample confirm that these objects have not yet evolved into planetary nebulae. Thus, the transformation from spherical to aspherical geometries has already fully developed by the time these dying stars have become preplanetary nebulae. From this new and surprising result, we hypothesize that the transformation to bipolarity begins during the very late AGB phase, and happens very quickly, just before, or as the stars are evolving off the AGB. We propose to test this hypothesis quantitatively, through a SNAPshot imaging survey of very evolved AGB stars which we believe are nascent preplanetary nebulae; with our target list being drawn from published lists of AGB stars with detected heavy mass-loss {from millimeter-wave observations}. This survey is crucial for determining how and when the bipolar geometry asserts itself. Supporting kinematic observations using long-slit optical spectroscopy {with the Keck}, millimeter and radio interferometric observations {with OVRO, VLA & VLBA} are being undertaken. The results from this survey {together with our previous work} will allow us to draw general conclusions about the onset of bipolar mass-ejection during late stellar evolution, and will provide crucial input for theories of post-AGB stellar evolution. Our survey will produce an archival legacy of long-standing value for future studies of dying stars. ACS/HRC 10377 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 coronagraphic monitoring is required to assess the changing position of the spots. ACS/HRC 10431 A Search for Faint Companions of Altair We propose to use the innovative new technique of spectral deconvolution {Sparks & Ford 2002} to search for very faint companions, possibly extrasolar planets shining by reflected light, around Altair, the nearest bright, single star to the Sun. The technique offers a Poisson-limited detection capability that brings Jovian-class planets into the realm of feasibility for a select few stars. We turn the wavelength dependence of the coronagraphic PSF to advantage and use it to eliminate stray light from the host star. As part of the detection process, we obtain a spectrum over the wavelength range, 750 nm to 1 micron, with 9% resolution. The search will be orders of magnitude more sensitive than all previous efforts and should take us to within about an order of magnitude of the Jovian luminosity flux limit. 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/WFC 10334 i-Band Dropouts around High-z Radio Quasars We will carry out deep F606W/F814W or F775W/F850LP imaging of three high-redshift radio quasars to search for an excess of dropouts. Also see program 9291 and 9777. ACS/WFC/WFPC2 10092 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. ACS/WFC/WFPC2 10241 An ACS H-alpha Survey of the Carina Nebula We propose an H-alpha ACS imaging survey covering 540 square arcminutes of the Carina Nebula, including an unbiased survey of the bright core, and several prominent dust pillars in the rich southern region of the nebula. Carina provides an important link between well-studied nearby H II regions like Orion, and more distant mini-starbusts like 30 Doradus. CVZ orbits will allow extremely efficient use of HST to map a large area of this complex and important region -- more than 95 percent of the proposed survey will be observed by HST for the first time. This survey will provide a complete census of microjets, proplyds, and silhouette disks with diameters as small as 200 AU, enough to spatially resolve disks like those in Orion, and will provide the first catalog of outflows {jets} from embedded low-mass stars, thin filamentary shocks, and wind-wind collisions in Carina. An accurate census of these phenomena is needed to characterize the star formation activity and gas dynamics as a function of position in the nebula, and to determine if models for protoplanetary disk evaporation from Orion are applicable in more extreme regions. Our previous ground-based optical and IR surveys have already revealed dozens of candidates for this type of activity -- but this is just the tip of the iceberg. Our proposed HST/ACS survey promises to be a bonanza for understanding ongoing low-mass star formation influenced by extremely high-mass stars. FGS 10202 Resolving OB Binaries in the Carina Nebula, Resuming the Survey In March 2002 we carried out a small, high-angular resolution survey of some of the brightest OB stars in the Carina Nebula with FGS1r in an attempt to resolve binary systems which had thus far evaded detection by other techniques. Of 23 stars observed, 5 new OB binaries were discovered with component separations ranging from 0.015" to0.325". This yield over the spatial domain of FGS1r's angular resolution, coupled with published statistics of the incidence of OB stars in short-period spectroscopic, and long-period visual binaries suggests that the fraction of binarity or multiplicity among OB stars is near unity. Our unexpected resolution of the prototype O2 If* star HD 93129A as a 55 milli-arcsecond double is a case in point that great care must be exercised when one attempts to establish the IMF and upper-mass cuttoff at the high-mass end of the HR diagram. We propose to resume the survey to observe a larger, statistically meaningful sample of OB stars to establish a firm assessment of multiplicity at the high-mass end of the IMF in these clusters. We will also investigate the single- star/binary-star status of several astrophysically important, individual stars in order to enable a better understanding of the evolution of high-mass 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. 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. NIC3 10337 The COSMOS 2-Degree ACS Survey NICMOS Parallels The COSMOS 2-Degree ACS Survey NICMOS Parallels. This program is a companion to program 10092. 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. WFPC2 10363 WFPC2 CYCLE 13 Intflat and Visflat 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 12 program 10075. The images will provide a backup database 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 12, we plan to continue to take extra visflat, intflat, and earthflat exposures to test the repeatability of filter wheel motions. FLIGHT OPERATIONS SUMMARY: Significant Spacecraft Anomalies: (The following are preliminary reports of potential non-nominal performance that will be investigated.) HSTAR 9753: GSACQ(2,1,1) fine lock backup, scan step limit exceeded on FGS1 @087/1625z GSACQ(2,1,1) at 087/16:22:03 ended in fine lock backup on FGS 2 due to scan step limit exceeded on FGS 1 at 16:25:40. Observations affected: ACS 34. Under investigation. COMPLETED OPS REQs: 17710-0 R/T Map @088/0143z OPS NOTES EXECUTED: None SCHEDULED SUCCESSFUL FAILURE TIMES FGS Gsacq 09 09 FGS Reacq 07 07 FHST Update 15 15 LOSS of LOCK SIGNIFICANT EVENTS: None |
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