+--------------------------------------------------------+ | STScI Analysis Newsletter (STAN) | Cosmic Origins Spectrograph (COS) | Space Telescope Imaging Spectrograph (STIS) | February 2012 +--------------------------------------------------------+ In this Newsletter we provide some updates of interest to COS and STIS users who will be drafting and submitting Phase 1 HST programs over the next several weeks. -------------------------------------------------------------- New ETC Release (20.1.1): Changes in the FUV sensitivity and new throughput curves The COS-related changes included in the new ETC release are listed in this article. Observers are encouraged to consider these changes when preparing their Cycle 20 phase I proposals. -------------------------------------------------------------- STIS CCD E1 Aperture Positions Observers planning to use STIS CCD spectroscopy modes are reminded of the usage of the E1 position and the central position when designing their phase I proposals. -------------------------------------------------------------- Common Mistakes that Can Ruin Your Data and Your Program There are several issues related to HST program implementation that are entirely proposer responsibilities, which STScI does not have the resources to verify systematically. They are explained in our documentation, and user tools are provided to address them, but there continue to be failures caused by proposer oversights in these areas. Observations that fail for these reasons will not be repeated. -------------------------------------------------------------- Time Variability of the STIS FUV MAMA Dark Rate Observers using the STIS FUV MAMA detector are reminded that the instrumental background for this detector is highly variable. The causes of this variability and ways to mitigate such high dark rates are explained in this article. -------------------------------------------------------------- CalCOS v2.15.4 Installed in OPUS CalCOS v2.15.4 was installed in OPUS on January 12, 2012. Important new features for this release include a calibration step to correct for Y-walk and a TIMELINE extension for corrtag files. A detailed list of changes related to CALCOS v2.15.4 can be found on the "CALCOS Release Notices" web page http://www.stsci.edu/hst/cos/pipeline/CALCOSReleaseNotes/notes/). -------------------------------------------------------------- New Photometric Conversion Tables and Ripple Tables for the STIS Echelle Modes New Photometric Conversion Tables and Ripple Tables for the STIS NUV and FUV MAMA Echelle modes were delivered for use in On the Fly Reprocessing on November 8, 2011 for use with post- Servicing Mission 4 (SM4) data. These tables reduce the echelle absolute flux calibration uncertainty to less than 5%; an improvement of 3% compared the tables previously used for post-SM4 data. Shifts of the echelle blaze function with time continue to be monitored and will be characterized in the near future. At this time, the shifts affect the echelle flux calibration less than 5%. See STIS ISR 2012-01 for more details. -------------------------------------------------------------- +----------------------------------------------------------+ | 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. +----------------------------------------------------------+
