SPECTRO-NEBULAGRAPH - A TRIDIMENSIONAL-SPECTROSCOPIC SYSTEM BASED ON A LOCAL-AREA NETWORK OF PERSONAL COMPUTERS

Spectro-nebulagraph (SNG), a tridimensional-spectroscopic system, has been developed as a versatile observation system attached to the Casse grain focus of the 1.88-m telescope at the Okayama Astrophysical Obser vatory. Tridimensional spectra, i.e., so-called data cubes, are obtain ed by sweeping the telescope in the direction perpendicular to the sli t of a spectrograph step by step. From the data cube, various monochro matic images can be extracted by data processing. SNG consists of four devices, i.e., the telescope control system, the autoguider, the spec trograph, and the CCD camera, which are distributed on a personal-comp uter network. The control software for SNG performs cooperative contro l of four devices in an automated fashion according to a programmed se quence of procedures. Some observational results taken with SNG are sh own for 3C 120, NGC 4449, and NGC 3646.