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IUE Project Electronic Newsletter

NASA-Goddard Space Flight Center (GSFC)

Vol. 5, No. 8 - August 1997


IUE Conference in Sevilla, Spain

The final IUE conference, entitled Ultraviolet Astrophysics Beyond the IUE Final Archive, will be held in Sevilla, Spain, on 11-14 November 1997. This conference will address those astrophysical problems which have been solved (and raised) as a consequence of 18.5 yrs of IUE observations. It will also highlight the enormous expansion in the understanding of a wide range of phenomena, from planetary magnetospheres to the environment near massive black holes in AGNs. In addition, the conference will review the current and future space instruments covering the ultraviolet domain.

The calendar of events include:

Early Registration Deadline: 1 September 1997
Registration Deadline: 19 September 1997
Receipt of Abstract Deadline: 1 October 1997
Conference: 11-14 November 1997

For additional information, check

http://www.vilspa.esa.es/iue/iue.html

- Ron Oliversen


IUE Image Processing News

LWR High-Dispersion Processing About To Begin!

We are performing the final tests of the updates to the NEWSIPS processing system so that we can process LWR high-dispersion images. Production processing is expected to begin by mid-August. You are welcome to send us your priority processing requests. Please use our web-based request procedure at

http://hypatia.gsfc.nasa.gov/IUE/search/IUE_usrreq.html

NEWSIPS Information Manual

Version 2 of the manual is nearing completion. This version adds information on high-dispersion and LWR low-dispersion NEWSIPS processing to what was available in Version 1. Thus Version 2 will supercede Version 1. We plan to publish the manual as a NASA IUE Newsletter and make it available via the Web.

Status of NEWSIPS Processing

We are on track to finish the NEWSIPS processing of all NASA images by the end of September. Here is how each data set stands as of August 7, 1997.

SWP low dispersion: 96% processed and archived.
LWP low dispersion: 96%
LWR low dispersion: 83%
SWP high dispersion: 96%
LWP high dispersion: 92%
LWR high dispersion: 0%

For the datasets with 96% completion, the remaining images include various types of problem images and engineering images.

We note that the SWR images, as well as the FES images, are not being reprocessed as NEWSIPS data. The original IUESIPS versions of these data will continue to be available, if anyone wishes to use them.

Questions?

If you have any questions about IUE processing or the Final Archive, please feel free to contact me any time at imhoff@iuegtc.gsfc.nasa.gov or at 301-286-1470. Thanks!

- Cathy Imhoff


Recent IUEDAC Software Changes

Since 01-Jul-1997:
9-Jul
The following routines were implemented:
linterp, gridterp, kurucz91
prolog modifications.
ftoa
new routine to convert MXLO wavelengths and fluxes to ASCII table files.
iuerip
includes NEWSIPS LWP ripple correction parameters.
nsripl
new routine to derive and display ripple correction for NEWSIPS high dispersion spectral orders.
new_splice
uses non-heliocentric velocity corrected wavelengths for deriving splice points for NEWSIPS high dispersion spectral orders.
14-Jul
A new version of label was implemented which properly displays label appendage information stored in NEWSIPS files.
29-Jul
The following routines were implemented:
readmx
includes the /noisecal keyword option for calibrating high dispersion noise vectors.
errbar
allows the use of different symbols for displaying error bars.

The latest changes to the program readmx probably deserve further comment. As many of you are aware, the noise vector included in the high dispersion MXHI file is uncalibrated, and as such, can not be used to estimate the error in absolute fluxes (unlike the sigma vector, which can be used for low dispersion absolute fluxes). The noise vector is based on empirical noise models (derived from evaluating the scatter in regions of photometrically-corrected flat field images) and was originally intended solely for flagging "bad pixels". It was never evaluated as an error estimator. The value associated with a given wavelength and stored in the MXHI file is simply the sum of the estimated noise for each pixel in the extraction slit.

After several requests for a high dispersion error estimator, readmx was modified to offer the user the option of calibrating the noise vector. Basically, when the /noisecal keyword is specified, readmx multiplies the noise vector by the ratio of the absolute flux to the net flux. This results in both the noise vector and the absolute flux vector having units of ergs/cm**2/Å/sec. The program errbar can then be used to superimpose error bars on a plot of absolute flux versus wavelength. However, users should still use caution in trusting the accuracy of the calibrated noise vector and should treat it as no more than a rough error estimate.

- Randy Thompson


IUE Documents - Big Sale! Everything Must Go!

We still have some copies of various IUE Newsletters, manuals, and atlases available. This is your last chance to get copies of your very own! Please contact me at imhoff@iuegtc.gsfc.nasa.gov or 301-794-1470 if you would like copies of any of these documents.
  • Various NASA IUE Newsletters (not all volumes available)
    • Special volumes:
      • IUE Observing Guide - Vol. 47
      • IUE Spectral Atlas II - Vol. 43
      • NEWSIPS Information Manual (Version 1; see below) - Vol. 53

  • IUESIPS Information Processing Manual (Version 2)

  • NEWSIPS Information Processing Manual
    • Version 2 soon to be available - will be published as a NASA IUE Newsletter
    • Version 1 (LWP and SWP low-dispersion only) still available but will be superceded by Version 2

  • NASA Reference Publ. 1285: IUE Spectral Atlas of Selected Astronomical Objects, by C.-C. Wu et al., 1992

  • NASA Reference Publ. 1312: Spectral Classification with the IUE: An Atlas of B-Type Spectra, by J. Rountree and G. Sonneborn, 1993

  • NASA Reference Publ. 1363: IUE Atlas of B-Type Spectra from 1200 to 1900 Å, by N. Walborn, J. Parker, and J. Nichols, 1995

- Cathy Imhoff


The IUE Electronic Newsletter, edited by James Caplinger, is primarily intended to inform the numerous remote and local users of the IUEDAC software of recent software updates, as well as let them know about news relating to the IUE project in general. If you want your name to be added to, deleted from, or changed on our distribution list, please send us e-mail to

news@iuedac.gsfc.nasa.gov

or send a postcard to:

IUE Data Analysis Center (IUEDAC)
Code 686.9, NASA-GSFC
Greenbelt, MD 20771


* IUE Data Analysis Center * IUE Project *


Webmaster

Mr. James R. Caplinger, Computer Sciences Corporation

Responsible NASA Organization/Official

Dr. Don West, IUE Operations Scientist