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February 1995                                 Volume 3, No. 2


This is an electronic newsletter edited by the IUE Data Analysis Center (IUEDAC)intended to inform the numerous remote and local users of the IUEDAC software of recent software updates and project changes.


    The VMS version of the IUEDAC software and database files have been updated and are now available for distribution in the IUE Anonymous FTP account. A new version of the VAX VMS installation guide (INSTALL_VAX.TEX) is also available in the same account. Users should be cautioned that the installation procedure required for the new software has changed slightly, primarily because IDL system variables have replaced the use of VMS logicals for describing the IUERDAF account structure. (Note the unix version of the updated IUEDAC software was added to the anonymous ftp account on iuesn1 last month.) Also available in the anonymous ftp account is a newly revised and expanded IUEDAC Users Guide. The 132-page LaTeX document is stored in the file GUIDE.TEX. rwt

  • Progress on the IUE Final Archive
  • The Image Processing Center is making great strides in processing archival IUE images with the NEWSIPS software. We have essentially completed the first set of SWP data ("Set 1" = dispersion images taken by NASA before 1990; image numbers < 37929). In addition, we have nearly completed processing the first set of LWP data (also "Set 1"; image numbers < 17058). There are some engineering and sky background images yet to process, plus a few "problem" images (e.g. bad raw data). The data may be obtained from the NSSDC NDADS system. Some of the LWP images have not yet been written into the system, but that should happen in the next few weeks. The next data set we plan to process are the SWP and LWP low-dispersion images taken after 1990 ("Set 2"). At this time, the calibration task is working on updating the wavelength calibration and sensitivity degradation corrections. In addition, we are updating the database entries for the homogeneous data and collecting the raw images. When all these pieces are ready, we can begin processing these data sets. Is the one image you absolutely need a VILSPA or recent image, which is not available? We can process a few such images on special request. Any such processing is "unofficial" and the data will not be archived. For details, contact Cathy Imhoff at or (301) 794-1470.

  • What Are the Homogeneous Data?
  • Have you ever searched the IUE Merged Log for a particular object and been frustrated by the various names and coordinates used by various Guest Observers? The IUE Project has tried to help with this problem by defining what we call "homogeneous data" for each image. This is a set of uniformly defined catalogs, names, and coordinates for the various astronomical objects observed by IUE. These were defined with the support of the Centre de Donnees Astronomiques de Strasbourg, thus drawing on the SIMBAD database, and VILSPA. You will find the usual SIMBAD style entries for the homogeneous catalogs and object names. In addition, there is a complementary ID to add specific information (e.g. Star #13 in a cluster). Three special catalog designations were created to accommodate IUE data: IUE (IUE specific images such as wavecals and nulls), ZZ (solar system objects), and MC (LMC and SMC objects). So an observation of Jupiter's Red Spot would appear as catalog = ZZ, homogeneous ID = JUPITER, and complementary ID = RED SPOT. In addition, for each object there is a unique set of coordinates. These are helpful primarily for point-source "fixed" objects such as stars. For observations of extended sources such as nebulae and galaxies, the homogenous coordinates are typically for the center of the object. The Guest Observer-specified coordinates and the comments in the FITS headers should be examined to determine the exact pointing for such objects. For solar system objects, the GO coordinates are copied over into the homogeneous coordinates. Currently the homogeneous data are available in the FITS headers of NEWSIPS processed data. cli

  • IUE Atlases Available
  • We have two very useful IUE spectral atlases available on request. "IUE Ultraviolet Spectral Atlas" by C.-C. Wu et al. 1991, NASA IUE Newsletter, No. 43. Plots IUE spectra, tabulates fluxes for MK standard stars. "IUE Ultraviolet Spectral Atlas of Selected Astronomical Objects" by C.-C. Wu et al. 1992, NASA Ref. Publ. No. 1285 Plots IUE spectra, tabulates fluxes for planets, variable stars, galaxies, etc. If you would like a copy or two, please contact Cathy Imhoff at or (301) 794-1470. cli

  • Recent System Changes:

    2/08/95 - OpenVMS version 6.1 installed

    Recent Software Changes:

    27-Jan Almost all of the experimental library routines have now been implemented. Most of the ~100 new programs include changes for improving software portability and should not impact users. Included in the implementation however is a new version of SEARCH which allows users to submit NEWSIPS reprocessing requests. 30-Jan Minor errors were corrected in the implemented versions of IUEFX, STPAR, and BS_INOUT. 03-Feb Faster versions of the FITS reading routines IFITSRD, IUE3DRD, IUEATRD, and IUEARRD have been added to the experimental library 07-FEB New experimental routines: LORFIT - lorentzian distribution function (compatible with WFIT) PFIT - power law function (compatible with WFIT) STDSFILE - standard star database search routine RDSTDS - extracts corrected fluxes from online standard star spectra BINS - new keyword for writing results to a disk file WEIGHT - more flexible weighting using nu flags 14-FEB New versions of the FITS reading routines IFITSRD and IUE3DRD have been added to the experimental library which allow reading multiple rows of a FITS binary table extension containing variable length array fields. rwt

    Editor: Dr. Michael Carini Contributors: Mr. Randy Thompson Dr. Tom Meylan Ms. Pat Lawton Ms. Lyla Taylor Dr. Cathy Imhoff

    Web Curator:

    Dr. Michael Carini, Science Programs, Computer Sciences Corporation.

    Responsible NASA organization/official:

    Dr. Don West, IUE Operations Scientist.