The problem of extinction and thermal reradiation by dust in active galactic nuclei and quasi-stellar objects

Charles Congdon, Wayne A. Stein
1989 Publications of the Astronomical Society of the Pacific  
Published Ha/Hß ratios and infrared to visual flux ratios are examined as potential diagnostics for dust in Seyfert 1 galaxies, Seyfert 2 galaxies, and QSOs. Ha/Hß ratio distributions are very broad although some subtle distinctions may be evident among the various classes of objects. The distributions of the ratio of X ~ 10-|xm luminosity to that at visual-ultraviolet wavelengths are more narrow, and clear distinctions are evident among the various types of object. Clearly both Ha/Hß and
more » ... ed emission together help determine the obscuring effects of dust. More homogeneous data are desirable but will require considerably large telescope observing time in order to pursue these results further.
doi:10.1086/132490 fatcat:tfiqfj3hizgqteyxsiqtlrhcxi