This paper describes the OES echelle spectrograph, a new coudé focus instrument of the 2 m telescope at Ondřejov Observatory. The design, optical scheme, and mechanical solutions are presented. A brief review of laboratory tests is given, too.
We present a manual for the reduction of data exposed by the fiber-fed echelle spectrograph HEROS. As the reduction process is really not trivial in fiber echelle spectrography (mainly due to instabiities leading to wave-like patterns in merged spectrum), we remind and discuss the most important influences (if they are known) evoking cited instabilities. Nevertheless, the main accent is put on the reduction process description, list of MIDAS commands, and finally on the description of HEROS arrangement of some MIDAS routines.
The reduction of echelle data (and fiber-fed echelle data especially) is a quite complicated process since there are many unpredictable effects; they may evoke some instabilities in exposed spectra. As consequences of these, there are problems with merging spectral orders - merged continuum exhibits characteristic wave-like patterns. Of course, these structures complicate broad liner measurement (Hα etc.) - thus it is advisable to describe all complications and effects and minimise them, if possible. We have put main accent to the temperature and torsion influences. We will continue with experiments described in this paper; final results and some summary will be published in future.