Analysis software for spectra?

Well, if you fancy a steep leaning curve and want to do what the
professionals do then try IRAF (http://iraf.noao.edu or the UK mirror
at http://www.starlink.ac.uk/iraf/web). It is free to download and use,
but will probably require a few(!) lessons on how to use it properly.

If you want to install it then you'll ned a copy of Linux (or some
other flavour of Unix). To'm Iraf Notes
(http://cholla.as.arizona.edu/computers/iraf.html) give a easy to
understand set of instructions on how to get it up and running on your
system.

Failing that, you could use Octave (http://www.octave.org) which is a
Matlab clone and is available for Linux and Windows. You could simple
read your image into an array, align it so that your spectral lines are
vertical, and the sum down the image. GNUPlot can then be used to show
your spectra and save them as Postscript or similar).

Hope that helps! If you (or anyone else) wants any help with
post-processing their spectra then feel free to drop me an email.

Cheers,
John D. Tanner

(You'll have to remove the spam catcher from the above email address)