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Date and Time of the Query: 2019-06-15 T21:52:21 PDT
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For refcode 1990ApJ...360..474V:
Retrieve 23 NED objects in this reference.
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NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
1990ApJ...360..474V THE LINERS REVISITED S. M. VIEGAS-ALDROVANDI Department of Physics, Ohio State University AND R. B. GRUENWALD Instituto Astronomico e Geofisico, Universidade de Sao Paulo Received 1988 December 16; accepted 1990 March 12 ABSTRACT In order to discuss the source of energy in LINERs, a large sample of objects is analyzed. The observed emission-line ratios are compared to theoretical values given by photoionization models, including or not the effect of relativistic electrons, and by shock models. All models are built assuming a distribution of emitting clouds. The results are plotted in several diagnostic diagrams for the emission lines usually observed in LINERs. The main conclusions can be summarized as following: the standard optically thick photoionization models cannot describe the entire range of observed line ratios, even if clouds of different densities are present. The contribution of shocks or relativistic particles, or both, must be taken into account to have a better picture of these objects. Subject headings: black holes - galaxies: nuclei - radiation mechanisms - shock waves
Retrieve 23 NED objects in this reference.
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