February 1995                                 Volume 3, No. 2


IUE DATA ANALYSIS CENTER  NEWSLETTER



               
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.



 UPDATED IUEDAC SOFTWARE AND DOCUMENTATION 
NOW AVAILABLE  

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

 
 IUE IMAGE PROCESSING NEWS

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 imhoff@iuegtc.gsfc.nasa.gov 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
imhoff@iuegtc.gsfc.nasa.gov or (301) 794-1470.

cli 

 
 IUEDAC SOFTWARE AND HARDWARE UPDATES 

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:

Responsible NASA organization/official: