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IUE Project Electronic Newsletter

NASA-Goddard Space Flight Center (GSFC)

Vol. 5, No. 10 - October 1997


Would the Last One Out, Please Turn Out the Lights!

At 21:30UT on 1997 October 9, the NASA IUE project ceased to exist. This follows last year's termination of the very productive and still working IUE satellite at 18:42UT on 1996 September 30. The IUE legacy is 104,000 observations of about 10,000 objects over 18.7 years and the training of a couple thousand astronomers in space astronomy. The IUE project is very proud of its work and of the many dedicated people, both inside and outside of the project, that have served the project and the astronomical community.

We have finished the processing of the NASA IUE images for the Final Archive; likewise, the ESA IUE images will be finished by the IUE project at VILSPA in early 1998. It is important to remember the NEWSIPS software was a mass production pipeline processing effort and compromises had to be made. Although many significant improvements were made, including the creation of a homogeneous data set, correction for fixed pattern noise, increased wavelength coverage below 1200Å to 1150Å, and better calibration, it does not mean we have corrected all systematic errors or that individual customized reductions will be unnecessary. For example, improvements are possible in the spectral extraction of high dispersion data to achieve an even greater signal-to-noise ratio. Nevertheless, we believe you will find the IUE data useful for years to come.

IUE was the little satellite that could. However, this was only possible through your support, and we are grateful. We leave you with an advertisement that appeared in the Goddard Employees Welfare Association newsletter several years ago:

1978 UV satellite. 80K imgs taken, 1.5 gyro
left, ops. staff incl, fair cond, 10M or
bo. 301/717-1181.

- Ronald J. Oliversen, IUE Deputy Project Scientist


IUE Archival Support

IUE archival support will continue through a small base of people with IUE Project knowledge located at the Space Telescope Science Institute, effective 1997 October 13. So if you have questions about the Final Archive Data, using the IUEDAC software, or obtaining the IUE data, please contact one of the four people listed below.

Catherine Imhoff imhoff@stsci.edu
Karen Levay klevay@stsci.edu
Myron Smith msmith@stsci.edu
Randy Thompson rthompson@stsci.edu or rthomp@stsci.edu

- Karen Levay


Status of NEWSIPS Processing

Processing of images through the NEWSIPS software for the IUE Final Archive is now complete. A total of 71,058 images were processed and archived - every processable image which is scientifically useful. There were 421 images which were not processed either because the raw image is lost or corrupted (most when they were originally archived), or the image was a very early engineering test image.

LWP low 13901 images
LWP high 7614 processed
LWR low 7773 and
LWR high 4578 archived
SWP low 24315
SWP high 12917
Total 71058 (phew!)

VILSPA is continuing to process their images. Their projected completion date is in early 1998. We are placing the VILSPA processed images into the NDADS archive as they are received.

If you have any questions about IUE data or the NEWSIPS processing, please contact me at my new email address at imhoff@stsci.edu.

- Cathy Imhoff


IUEDAC Software Changes

Since 01-Sep-1997

10-Sep
The following routines were implemented:
iuefx
uses a different temporary file when file keyword is used and lists additional NEWSIPS data types
iuerip
includes NEWSIPS LWR ripple correction
newcalib
includes high dispersion absolute flux calibrations
mxcor
new routine for correcting error in LWR & LWP sensitivity degradation corrections (for wavelengths greater than 2712 Ångstroms)
corrcalib
subroutine of mxcor
11-Sep
The IUE merged log was updated. Processing information available through July 30th has been included.
18-Sep
New versions of the following programs were implemented:
ftoa
allows wavelengths, fluxes and sigmas from NEWSIPS MXHI files to be written to ASCII files (previous version only worked with MXLO files)
readmx
returns with vectors set to 0 if wrange values are outside extracted spectral region (rather than abort)
23-Sep
New versions of the following routines were implemented:
iuerip
uses THDA at end (rather than at start) of exposure for SWP ripple correction (as is coded in NEWSIPS)
nsripl
added /noplot option and uses double precision wavelengths in calculating NEWSIPS ripple corrections
25-Sep
A new version of mxcor was implemented which fixes a potential problem occurring when the corrected flux vector spans 3 FITS records in the MXHI file. The previous version however did not corrupt any data since the affected points were found to lie outside the calibrated region.
- Randy Thompson

Status of Data at the NSSDC

All GSFC processed data has been archived and is available from the NSSDC NDADS systems. All of the LWP and LWR high dispersion MXHI files have had the correct sensitivity degradation correction applied and have been rearchived. Currently, recently received VILSPA Final Archive data are being archived. We expect several more deliveries of VILSPA data which will be archived upon receipt. Any questions about the status of or problems retrieving IUE data in the NDADS archive may be addressed to me at levay@ndads.gsfc.nasa.gov.

- Karen Levay


System Status Report

One of the last new items available from our website are updated library distributions of the DAC software. These include all software changes made since the last update of 14 May 1997. Also, LaTeX and PostScript versions of the NEWSIPS Information Manual - Version 2 are available from the IUE anonymous ftp directory. This volume includes and supercedes all material in Volume 1, which covered only LWP and SWP low dispersion spectra.

The Goddard Laboratory for Astronomy and Solar Physics, which has provided our hardware support, has generously agreed to keep all IUE user accounts on a non-maintained basis for a time. This means that the accounts will be available until a hardware failure or system upgrade requires changes in the system configuration, after which the accounts will no longer exist.

While we can't predict when any changes might occur, we hope that the accounts will live for the next few months. Full backups of all guest user accounts (accounts USER1 to USER65) have been created as a contingency. Users who still have accounts on iuesn1.gsfc.nasa.gov (mainly current and former staff) should also be advised that backups will no longer be performed after this week, although a final backup set has been created.

On the other hand, full maintenance will continue on iuewww.gsfc.nasa.gov, since this system is used for other work. Our website will also continue for a time while the staff at Space Telescope prepare their website for IUE-related pages. Pointers will be posted when the new pages are ready.

- James Caplinger


Updated Search Interface

On the 30th of September, a redesigned version of the IUE WWW Search page (http://hypatia.gsfc.nasa.gov/IUE/search/) was implemented. This page now "feeds into" the Web Interface for Searching Archival Research Data (WISARD; http://hypatia.gsfc.nasa.gov/wisard/). IUE WWW Search was jointly developed by the IUE Project and the Astrophysics Data Facility (ADF). It served as the prototype to the ADF's WISARD. This change allows access to the SIMBAD and NED name resolvers, ADF IUE browser, and when starting from the WISARD page, astronomical mission archive catalogs in addition to the IUE Merged Observation Log. If you have any comments or questions, please contact Michael Van Steenberg at Michael.E.VanSteenberg.1@gsfc.nasa.gov or 301-286-7876.

- Pat Lawton, ADF UV Support


Future Work

The IUE contract has expired before several IUEDAC projects were completed. This was partly due to the high priority given to testing the NEWSIPS high dispersion software and implementing the high dispersion calibration files into the IUEDAC software. The various projects left to be completed include:
  • updating the IUEDAC Users Guide,
  • updating software libraries on PC, MAC, ULTRIX, and UNIX platforms,
  • completing mxcor2, a routine for applying the latest NEWSIPS LWR ripple correction (just received from VILSPA this week),
  • implementing new versions of the ripple correction routines to allow users to manually enter temperature values for deriving the SWP ripple correction,
  • revising the IUE merged observing log once the remaining data sets are received from VILSPA.

We expect some of this work may be completed under the new contract with STScI. We also hope to continue distributing monthly IUE e-mail newsletters, at least for the next few months. The newsletter will be used (for example) to inform users when the IUE anonymous ftp site and IUE web pages are moved to Baltimore.

- Randy Thompson


Goodbye, Farewell, and Amen

The IUE Electronic Newsletter was inaugurated fairly late in the history of the project, not even five years ago. In that time, we hope we have been able to offer you useful information about recent analysis software changes, image processing developments, and other information we hoped you would find helpful in the course of your dealings with IUE. On behalf of the project, I would like to express our gratitude to you, the members of our user community, for the suggestions, assistance, and moral support that you have provided for the almost 20 years that the project has been around.

Although the IUE Data Analysis Center will no longer exist as a separate entity, several key individuals who have worked with the project (in some cases, since before launch) will be moving to Space Telescope over the next few days. In their new surroundings, they will be able to carry on the IUE name and to assist new and long-time astronomers with the analysis and interpretation of spectra produced by this productive spacecraft. I hope you will join me in wishing them the best in their continuing mission. We also extend those good wishes to those who, for a variety of reasons, will not be continuing their association with the mission. Together, the community and the project, we were able to create a legacy of which we can all be proud.

- James Caplinger, Editor, IUE Electronic Newsletter


* IUE Data Analysis Center * IUE Project *


Webmaster

Mr. James R. Caplinger, Computer Sciences Corporation

Responsible NASA Organization/Official

Dr. Don West, IUE Operations Scientist