A Survey of the ISM in Elliptical Galaxies
Session 52 -- Elliptical Galaxies
Display presentation, Tuesday, 10, 1995, 9:20am - 6:30pm

## [52.19] A Survey of the ISM in Elliptical Galaxies

M.G. Pastoriza (IF-UFRGS, Porto Alegre, Brazil and STScI (visitor)), F.D. Macchetto (STScI), W. Sparks (STScI), M. Giavalisco (STScI)

The nature of the origin and future evolution of the gas and dust in elliptical galaxies is still a highly controversial subject. We have carried out an extensive program of observations of a selected sample of more than 100 nearby ellipticals, with the aim of studying the propierties of their interstellar medium and elucidate the origin of ISM. In our survey, carried out at the ESO 3.6m and NTT telescopes, we obtained deep V and R images as well as narrow-band H$_\alpha$ +[NII] deep exposures. From a combination of these data we have derived the distribution of gas and dust in these galaxies. Our results show that a large fraction of ellipticals contain dust and emission-line gas. The morphology and physical properties of these components appears to favour an external origin for the ISM in these galaxies. We will present statistical information on our sample, some early correlations of the physical properties infered from our data and those at other wawelengths (radio and X-ray) and will discuss some of the most striking examples of emmision-line gas in elliptical galaxies.