+--------------------------------------------------------+ | STScI Analysis Newsletter (STAN) | Cosmic Origins Spectrograph (COS) | Space Telescope Imaging Spectrograph (STIS) | September 2010 +--------------------------------------------------------+ In this newsletter we summarize import updates to the calibration pipeline and calibration reference files of COS and STIS. -------------------------------------------------------------- New Time-Dependent Spectroscopic Sensitivity Reference Files Delivered for COS and STIS As part of routine monitoring of spectrophotometric white dwarf standard stars, a time-dependence to the spectroscopic sensitivity of both COS and STIS has been characterized. For COS, new reference files have been delivered and are now routinely used in pipeline processing of data. For STIS, existing reference files have been updated based on trends observed in Cycle 17. -------------------------------------------------------------- Revisions to the Data Quality Flags for Calcos The Data Quality flags used by calcos have been redefined, and for the FUV channel, areas of the detector shadowed by grid wires are now excluded when creating the x1dsum spectra. -------------------------------------------------------------- COS G140L/1280 Wavelength Calibration Warning The zero point of the wavelength scale for the new COS FUV G140L/1280 mode is likely to be off by a few angstroms. Analysis to better characterize the wavelength range is on-going and better calibration is expected soon. -------------------------------------------------------------- COS Calibration Updates After the Cosmic Origins Spectrograph (COS) was installed on-board the Hubble Space Telescope (HST) in May 2009, it underwent an extensive calibration and characterization check-out during the Servicing Mission Observatory Verification (SMOV) period. The results from this program were used to update reference files and make changes to CALCOS, the COS data processing software. This article discusses enhancements to the standard data products. For the FUV, these include excluding detector regions affected by wire shadows when creating x1dsum files, pulse-height filtering to reduce background features. For the NUV channel, vignetting corrections have been incorporated into the flat field file, and for both channels, improvements have been made in the wavelength scales, flux calibrations, and data quality flagging. Furthermore, additional data are included in the FITS products to allow users to perform customized processing. -------------------------------------------------------------- Recent COS and STIS Instrument Science Reports Since HST Servicing Mission 4 a number of Instrument Science Reports (ISRs) have been published which characterize the behavior of COS and STIS. We provide a complete list of COS and STIS ISRs published since SM4. +----------------------------------------------------------+ | Need help? http://www.stsci.edu/hst/cos/help.html +----------------------------------------------------------+ | To subscribe or unsubscribe to the STAN, send a message | to majordomo@stsci.edu with a blank subject line and | the following in the body: [un]subscribe cos_news | or [un]subscribe stis_news +----------------------------------------------------------+ | The Space Telescope Science Institute is operated by the | Association of Universities for Research in Astronomy, | Inc., under NASA contract NAS5-26555. +----------------------------------------------------------+
