Abstract

TOVMASSIAN, Hrant M.  and  YAM, O.. Missing Seyfert Galaxies. Rev. mex. astron. astrofis [online]. 2011, vol.47, n.2, pp.357-360. ISSN 0185-1101.

The aim of this work is to estimate the number of Seyfert nuclei missing in catalogs due to obscuration by the dust disc in host spiral galaxies. We compared the distribution of inclinations of host galaxies of Sy1s and Sy2s with that of in control sample of spiral galaxies, and found that the relative number of Seyferts is higher in almost face-on galaxies with i < 30° and smaller in highly inclined, i > 61°, spiral galaxies without active nuclei. We conclude that the difference found is due to absorption of the Seyfert nuclei by the dust-disc of inclined galaxies. We estimate that about 100% and 50% of the observed Sy1s and Sy2s respectively are missing.

Keywords : galaxies [Seyfert].

        · abstract in Spanish     · text in English     · English ( pdf )