Echelle Spectra Reduction Procedures

IRAF

Try the IRAF routines first. Thet are heavily documented and will work in most cases. Maybe in all cases...

IRAF Tutorial: Echelle Slit Reductions with DOECSLIT Includes links to on-line help pages for the various tasks used by the doecslit script.
doecslit help page. Includes links to on-line help pages for the various tasks used by the doecslit script.
Get yourself a copy of A User's Guide to Reducing Echelle Spectra with Iraf by D. Willmarth and J. Barnes.

One Group's Home Brew

Several years ago we ran into problems using the IRAF routines to reduce echelle spectra of faint quasars. These were 2-hour exposures with the Tek2K, and typically had 12,000 cosmic rays on them. The IRAF optimal extraction routines gave bizarre answers: spectra set exactly to zero, spectra with the flux scale inverted, etc.

To get around this, we (J.Baldwin, G.Williger, R.Carswell) adopted optimal extraction routines originally written by Rauch et al. (1992, ApJ 390,387), incorporating them into IRAF scripts. These routines work OK in the blue, but probably won't give good results in the red where the sky spectrum is dominated by OH emission bands.

There is zero support for these routines. IRAF may have evolved enough so that they don't work any more. Click here for more info:

I'm out of my mind.

J.Baldwin
28 Dec 1995