<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <!--Converted with LaTeX2HTML 98.1p1 release (March 2nd, 1998) originally by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>Introduction</TITLE> <META NAME="description" CONTENT="Introduction"> <META NAME="keywords" CONTENT="vol2"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> <LINK REL="STYLESHEET" HREF="vol2.css"> <LINK REL="next" HREF="node678.html"> <LINK REL="previous" HREF="node676.html"> <LINK REL="up" HREF="node676.html"> <LINK REL="next" HREF="node678.html"> </HEAD> <BODY > <!--Navigation Panel--> <A NAME="tex2html9967" HREF="node678.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="icons.gif/next_motif.gif"></A> <A NAME="tex2html9964" HREF="node676.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="icons.gif/up_motif.gif"></A> <A NAME="tex2html9958" HREF="node676.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="icons.gif/previous_motif.gif"></A> <A NAME="tex2html9966" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="icons.gif/contents_motif.gif"></A> <BR> <B> Next:</B> <A NAME="tex2html9968" HREF="node678.html">Location of slitlets and</A> <B> Up:</B> <A NAME="tex2html9965" HREF="node676.html">Multi-Object Spectroscopy</A> <B> Previous:</B> <A NAME="tex2html9959" HREF="node676.html">Multi-Object Spectroscopy</A> <BR> <BR> <!--End of Navigation Panel--> <H1><A NAME="SECTION003610000000000000000"> Introduction</A> </H1> <P> The MOS context is written for the reduction of multi-object spectra obtained with numerous slitlets. Long-slit spectra are considered a special case of multi-object spectra and therefore not treated in a separate chapter. The MOS package is meant especially for the reduction of FORS data but may also be used for other MOS data. <P> It is assumed that the basic correction for bias, dark, and overscan are performed with standard MIDAS commands (maybe also using <TT>COMBINE/LONG</TT> to average several frames of the same type). There are no special MOS averaging commands. <P> During the whole description we assume that the detector is a CCD with the rows along the dispersion direction and the columns along the slit. <P> A demonstration of the package can be obtained with the command <TT>TUTORIAL/MOS</TT>, which has an automatic and an interactive mode and also allows to look at selected parts of the package. In order to create all necessary test data you should run it once automatically. <P> <BR><HR> <ADDRESS> <I>Petra Nass</I> <BR><I>1999-06-15</I> </ADDRESS> </BODY> </HTML>
