INES Frequently Asked Questions


  1. How can I read INES files? Is it necessary any special software?


  2. Which is the format of the INES files?


  3. Why the INES spectrum is different from the MXLO spectrum?


  4. Why the wavelength scales of INES and NEWSIPS high resolution spectra are different?


  5. I have measured the velocity of the MgII lines in INES high resolution spectra, and I get different values for both lines


  6. Where can I get more information about the INES System?

For further questions and/or comments, please contact us at the INES HelpDesk


How can I read INES files? Is it necessary any special software?

No special purpose software is necessary to read INES files. Click here for a description of how to read INES data under different environments.


Which is the format of the INES files?

INES files are written in standard FITS format. The data are stored as FITS binary tables, with a primary header and en extension header.


Why the INES spectrum looks different from the MXLO spectrum?

Low resolution INES spectra are extracted from the Final Archive bi-dimensional SILO files, but using modified software and noise models.
Differences with respect to the MXLO files are generally small, but there are specific cases in which both spectra may differ substantially. Large differences can occur in weak extended or miscentered spectra, or in spectra with weak continuum and strong emission lines.


Why the wavelength scales of INES and NEWSIPS high resolution spectra are different?

NEWSIPS SWP and LWP/R high resolution spectra present a systematic difference in the wavelength scale, in the sense that velocities measured in short wavelength spectra are more negative. In order to provide an internally consistent wavelength scale, a correction of +17.7 km/s has been applied to INES SWP Large and Small aperture high resolution spectra. For the same reason, a smaller correction, +13.7 km/s, has been applied also to LWP/R Small aperture spectra.


I have measured the velocity of the MgII lines in INES high resolution spectra, and I get different values for both lines.

That is true. There is a problem in the NEWSIPS LWP high resolution wavelength calibration that makes that the velocities measured on both lines of the MgII doublet at 2800 A differ systematically by 9 km/s, with the K line given the lowest value. The correct value is the one given by the K line. Note that this problem does not exist in the LWR camera, where both lines give velocities which differ on average by only 1 km/s.


Where can I get more information about the INES System?

The INES server installed in the National Hosts includes a documentation section in which you can find papers dealing with different aspects of the INES System, as well as other information such as the NEWSIPS Manual and the IUE Spacecraft Operations Final Report.

INES papers have also been published in the Proceedings of the Conference "Ultraviolet Astrophysics Beyond the IUE Final Archive", 1998, eds. W. Wamsteker, R. Gonzalez-Riestra and R. Harris, ESA SP-413.

INES related papers published in refereed journals are listed here.


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Last update: 11 March 2002