Ultra-low dispersion spectroscopy of stars and galaxies

Abstract

Application of ultra-low dispersion spectroscopy (10.000 Å mm-1) is described to study the nuclei of elliptical galaxies, the quassi - stellar objects and for the discovery of faint OB stars, reddened stars and red stars. The instrument used is an f/2 slit less spectrograph with a three degree quartz prism at the cassegrain focus of the 102-cm Ritchey-Chretien reflector at Kavalur. The spectra cover a field of 40 minutes of arc and the dispersion is 10,000 Å mm-1 . Ultra-Low dispersion spectra (micro spectra) were obtained for fifteen elliptical and three SO galaxies from the list of Ekers and Ekers (1973). Who classified them as compact and extended sources from the observations of radio emission at 6 cm. From an analysis of micro spectra and from direct photographs with graded exposure times. We find that all compact radio galaxies in the Ekers list also have optically compact nuclei. Some of these elliptical galaxies with compact nuclei. Some of these elliptical galaxies with compact nuclei show enhancement of intensity in the blue-violet region.