Accession Number : AD0772628

Title :   A Study of Possible Models for Balmer Emission Line Regions in Seyfert Galaxies,

Corporate Author : STANFORD UNIV CALIF INST FOR PLASMA RESEARCH

Personal Author(s) : Adams,William M.

Report Date : DEC 1973

Pagination or Media Count : 100

Abstract : The study is directed toward two unexplained phenomena exhibited by the Balmer emission lines in Seyfert galaxies; their unique profile structure, and their anomalous intensity ratios. The study of the line profiles consists of an examination of three proposed mechanisms for explaining the broad wings found on the Balmer lines in several of these objects. The models considered are: (1) a uniform medium in which self-absorption of allowed lines increases their escape path length, thus increasing the probability of their being electron scattered so as to account for the wings; (2) the line wings are formed in a separate region with high velocity dispersion; and (3) the lines with wings are formed in a separate region with high velocity dispersion; optical depth is greater, thus creating the wings by electron scattering. It is concluded that the evidence favors the third possibility. (Modified author abstract)

Descriptors :   *Galaxies, Emission spectra, Line spectra, Mathematical models

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE