The Calan/Tololo/Michigan Surveys

The Tololo surveys [173] also use objective-prism techniques and line-emission classification criteria. The nature of the objects in the lists of [92, 93, 94, 95, 96, 174] is discussed in [16] with the conclusion that, while only about one-third of Markarian-type galaxies have sufficiently strong emission lines to be included in the Tololo listings, the latter contain about 2% Class 1 Seyferts, 10% Class 2 Seyferts, with the remainder being galaxies with emission lines produced by hot stars. 30 Seyfert 1 galaxies are the first-reported objects in the Calan/Tololo thin uv prism survey for emission-line galaxies and quasars [122]; follow-up spectra are reported in [121].

Fairall [40] has divided the narrow-line emission objects into four groups based on morphological and spectroscopic studies of 47 galaxies from the Tololo surveys. These groups comprise systems where:

(a) the entire galaxy is an emission-line source. These are generally blue ellipticals with H / 4959 just less than unity;

(b) the outer regions are emission-line sources. These are generally outlying H II regions in late-type spirals;

(c) only the nucleus is an emission-line source. H / 4959 is low and these systems appear to be related to Class 2 Seyferts;

(d) multiple systems with high H / 4959.

Click here to see the NED representation of the Tololo Survey.

Click here to see the NED representation of the Michigan Survey.

Click here to see the NED listing of Calan/Tololo Seyferts.