+-----------------------------------------------------+ | HST Spectroscopy STIS/GHRS/FOS | | STScI Analysis Newsletter No. 10, Dec. 98 | | | +-----------------------------------------------------+ New HST Spectroscopy STAN Format & Content We are beginning a transition to a new format for the HST Spectroscopy STAN with this issue. At the top, an index of topics is listed with the web address where you can go to get all of the details. Below this, short summaries are provided for each topic. And as before, the STAN will be posted on the STIS web site, where all of these topics will be hypertext links directing you to the full writeup. All items appearing here and more are posted on the STIS web site, but we will only highlight items of particular interest or importance in the STAN. Change of Supported Apertures for E230H Exposure Time Incorrect in Interrupted STIS Exposures CALSTIS 2.0 Released Improved Cosmic Ray Rejection Parameters for STIS New STIS Reference Files CCD Hot-Pixel Alert for STIS Spectroscopic Observations STIS Fringing Tutorial Now Available GHRS `poffsets' Task not Reliable for Weak Data FOS Paper Products Now Support Spectropolarimetry FOS/BL Zero-Point Wavelength Correction Description List of Recent Preprints Now on Line +-STIS------------------------------------------------+ Change of Supported Apertures for E230H A change has been made to the supported apertures for the E230H grating for Cycle 8 which could affect your unexecuted Cycle 7 visits as well. We bring this to your attention now should you desire to make a change to your Cycle 7 program. Exposure Time Incorrect in Interrupted STIS Exposures When a STIS exposure is interrupted (i.e. for a guide star loss of lock), the take data flag (TDF) goes down, which prevents STIS from obtaining data. There are consequences of this event and a procedure to fix the problem. CALSTIS 2.0 Released A new version of CALSTIS (version 2.0) has been released and is now used in the pipeline (effective November 10, 1998). There are major changes, a number of additional enhancements and minor problem fixes, and updated tools released with this version. Improved Cosmic Ray Rejection Parameters for STIS The calstis pipeline includes a step to automatically reject cosmic rays in CR-SPLIT CCD exposures. A new parameter table has been installed to optimize the rejection. New STIS Reference Files Many updated reference files have been installed in the calibration pipeline. Among them are, the filter throughput for the UV imaging modes, new "PFLATS" for the MAMA detectors, and a new "LFLAT" for the FUVMAMA. CCD Hot-Pixel Alert for STIS Spectroscopic Observations Dithered images can be used to cure most of the hot pixels in STIS CCD imaging observations. However, removing hot pixels from spectroscopic observations can be more involved, and hence spectroscopic observations need some special consideration. STIS Fringing Tutorial Now Available There is a new ISR of particular interest for those people working in the Near-IR. ISR 98-29 will show you how to use the IRAF defringing tasks with your data. +-GHRS------------------------------------------------+ GHRS `poffsets' Task not Reliable for Weak Data The `poffsets' task, usually used with GHRS FP-SPLIT data, determines shifts. The cross correlation technique to determine wavelength offsets between individual spectra from spectral features (in default mode) is not reliable for weak or noisy features. +-FOS-------------------------------------------------+ FOS Paper Products Now Support Spectropolarimetry The paper product task 'pp_dads' has been enhanced to support spectropolarimetry data; the upgrade was part of the STSDAS release 2.0.2. FOS/BL Zero-Point Wavelength Correction Description Zero-point shifts in FOS/BL and FOS/RD wavelengths occurring between launch and de-commissioning are discussed and relevant Instrument Science Reports noted. Information on an IRAF/STSDAS cl script to be used to correct the wavelength files (.c0* files) for any FOS/BL (non-PRISM) observation is also provided. +-Spectrographs---------------------------------------+ List of Recent Preprints Now on Line The list of preprints based on HST spectrographs data that usually occupies this space is now available at the STIS web site for easy browsing. +-----------------------------------------------------+ | Need help? | | http://www.stsci.edu/cgi-bin/stis?cmd=help | +-----------------------------------------------------+ | To unsubscribe from this mailing list send email to | | majordomo@stsci.edu with the message: | | unsubscribe stis_news | +-----------------------------------------------------+ | The Space Telescope Science Institute is operated | | by the Association of Universities for Research in | | Astronomy, Inc., under NASA contract NAS5-26555. | +-----------------------------------------------------+
