Abstract
We discuss implications of Hopkins Ultraviolet Telescope (HUT) detections of C III λ977 and N III λ990 emission from the narrow-line region of the Seyfert 2 galaxy NGC 1068. In their discovery paper Kriss et al. showed that the unexpectedly great strength of these lines implies that the emitting gas must be shock-heated if the lines are collisionally excited. Here we investigate other processes which excite these lines in photoionization equilibrium. Recombination, mainly dielectronic, and continuum fluorescence are strong contributors to the line. The resulting intensities are sensitive to the velocity field of the emitting gas and require that the turbulence be of the same order of magnitude as the observed line width. We propose optical observations that will decide whether the gas is collisionally or radiatively heated.
Document Type
Article
Publication Date
1-10-1995
Digital Object Identifier (DOI)
http://dx.doi.org/10.1086/187714
Repository Citation
Ferguson, Jason W.; Ferland, Gary J.; and Pradham, A. K., "The Origin of N III λ990 and C III λ977 Emission in AGN Narrow-Line Region Gas" (1995). Physics and Astronomy Faculty Publications. 155.
https://uknowledge.uky.edu/physastron_facpub/155
Notes/Citation Information
Published in The Astrophysical Journal Letters, v. 438, no. 2, p. L55-L58.
© 1995. The American Astronomical Society. All rights reserved.
The copyright holder has granted permission for posting the article here.