Reduction of Bidimensional Spectral

This paper presents an outline of the software, written by the author, for the reduction of bidimensional spectral data obtained with the Russian 6-meter telescope using the Multi-Pupil Field Spectrograph (MPFS). The MPFS uses diierent detectors, an IPCS and CCDs, in combination with a scanning Fabry-Perot interferometer, etc. The principal algorithms, concerning the basic reduction steps such as atteld correction , spectral extraction and separation, and wavelength calibration, are brieey described. Procedures were designed to run on an IBM-compatible computer under the MS-DOS operating system and may be transferred onto any platform that supports the C language. The method of bidimensional spectroscopy, proposed by Prof. G. Courtes (Cour-tes et al. 1987), allows one to get independent spectra of each contiguous spatial element in a eld, using a bidimensional array of lenses that form a grid of micro-pupils instead of a slit as in a classical spectrograph where these images are dispersed into spectra. The number of spectra, registered simultaneously, as well as the spectral range of data are limited by the size of the detector and the entrance eld of the spectrograph. Using square lenses permits optimum data sampling and is ideal for spectrophotometry, allowing complete integration of ux. The main advantages of integral eld spectroscopy are its ability to cover extended sources with the necessary spatial sampling matched with seeing conditions , independence of spectral resolution from seeing, and continuous spatial sampling. The Multi-Pupil Field Spectrograph (MPFS) was developed at the Special As-trophysical Observatory of the Russian Academy of Sciences in 1990, and is now extensively used for spectral observations with the 6-m telescope (Afanasiev et al. 1995). It provides simultaneous detection of about 100 individual spectra produced by a raster of 9 by 11 (or 8 by 16) lenses. The spatial sampling of the data is chosen by the observer depending on the seeing quality and may be varied from 0.3 00-1.6 00 per lens.