Colin Cox

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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 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)
A monthly focus monitoring of the Hubble Space Telescope (HST) is performed via the Phase Retrieval technique. This has recently relied on Advanced Camera for Surveys (ACS) Wide Field Camera (WFC) data. Due to the installation of Wide Field Camera 3 (WFC3) on board the HST as a part of Servicing Mission 4, a new camera suitable for the monthly focus(More)
1. ABSTRACT Astrometric calibrations of JWST will use observations of a reference field in the Large Magellanic Cloud. This field will itself be astrometrically calibrated using observations with ACS/WFC on HST. The higher-order geometric distortions of ACS/WFC have previously been calibrated to high accuracy. However, the absolute scale and orientation of(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)