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Published May 1, 1982 | Published
Journal Article Open

Infrared, optical, and ultraviolet observations of hydrogen line emission from Seyfert galaxies


Nearly simultaneous observations are reported of Pɑ, Hɑ, and Hβ emission from 18 Seyfert galaxies and of Lyɑ from eight of these galaxies. In many cases, Pɑ is stronger relative to the Balmer lines than is predicted by recombination calculations; reddening appears to be required. Dispersion in the Pɑ/Hɑ/Hβ ratios orthogonal to the reddening track indicates that high densities or optical depths also affect the line flux ratios. Several galaxies, notably NGC 1275, have very low Pɑ/Hɑ ratios. High densities, large optical depths, and reddening probably all contribute to the low observed Lɑ/Hβ ratios.

Additional Information

© 1982 American Astronomical Society. Received 1981 September 25; accepted 1981 November 13. We thank W. L. W. Sargent, A. G. deBruyn, A. C. S. Readhead, and J.B. Oke for supplying optical spectra used in this paper and R. C. Puetter for helpful criticism. We are also grateful for the assistance of Juan Carrasco, Howard Lanning, Ron Koehler, Frank Cheigh, and the crew of the Kuiper Airborne Observatory. This work was supported by grants from the NSF and NASA.

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Published - 1982ApJ___256___75L.pdf


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