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Heterotrophic microbial communities in seawater and sediments metabolize much of the organic carbon produced in the ocean. Although carbon cycling and preservation depend critically on the capabilities of these microbial communities, their compositions and capabilities have seldom been examined simultaneously at the same site. To compare the abilities of(More)
In Arctic marine bacterial communities, members of the phylum Verrucomicrobia are consistently detected, although not typically abundant, in 16S rRNA gene clone libraries and pyrotag surveys of the marine water column and in sediments. In an Arctic fjord (Smeerenburgfjord) of Svalbard, members of the Verrucomicrobia, together with Flavobacteria and smaller(More)
The ACS solar blind channel (SBC) is a photon-counting MAMA detector capable of producing two-dimensional imaging in the UV at wavelengths 1150– 1700Å, with a field of view (FOV) of 31 ×35. We describe the on-orbit performance of the ACS/SBC from an analysis of data obtained from the service mission observatory verification (SMOV) programs. These data show(More)
The off-axis location of the Advanced Camera for Surveys causes strong geometric distortion in all detectors – the Wide Field Camera (WFC), High Resolution Camera (HRC), and Solar Blind Camera (SBC). Dithered observations of rich star cluster fields are used to calibrate the dirtortion. We describe the observations obtained, the algorithms used to perform(More)
We provide some background on pointing ACS, and present the dither and mosaic patterns that will be provided as a convenience for HST Cycle 11 Phase II proposal writers. This report supersedes any previous documents which describe specific ACS dither and mosaic patterns-namely, ACS Instrument Science Report 98-02 by Stiavelli, and the engineering versions(More)
The number of hot pixels on the Wide Field Channel of the Advanced Camera for Surveys will increase over the next few years as radiation damage accrues. A considerable reduction in dark rate and hence hot pixel counts should result from lowering the detector temperature. When the Aft Shroud Cooling System is installed in Servicing Mission 4, temperatures as(More)
The WFPC2 distortion solution has been presented by Holtzman et al. in the WFPC2 SMOV report and submitted for publication (Holtzman et al.1994). This solution together with a WFPC2 observation of the open cluster M67 has been used to establish the scales and rotations with respect to the HST V2 V3 coordinate system. The Holtzman solution relates pixel(More)
SBC dark images have been collected to provide dark current subtraction for science images and to monitor the instrument health and performance. Cumulative images which add counts from the whole history of the detector's use are also generated to anticipate any long-term degradation in performance. Images collected to date show no loss of efficiency or(More)
The dark count rates in the STIS MAMA detectors have been monitored. This report covers the period since the Servicing Mission 4 of May 2009. We find both long-term and short-term variations which for the NUV side we express as a function of date and temperature. The NUV dark rate has declined significantly from its surprisingly high initial rate of 0.014(More)
We present software for determining accurate HST attitude from guidestar and velocity data. This permits mapping V2,V3 to RA & DEC. Example applications are discussed, and detailed instructions for use of this software are provided. After an HST observation, there is often the need to reconstruct the pointing history of the telescope, essentially mapping(More)