Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-26T22:24:08.528Z Has data issue: false hasContentIssue false
  • English
  • Français

Radiation Hydrodynamics of the Broad Line Region in Seyfert Galaxies and Quasars

Published online by Cambridge University Press:  12 April 2016

William G. Mathews
William G. Mathews*
Affiliation:
Lick Observatory and Board of Studies in Astronomy and Astrophysics, University of California, Santa Cruz, California 95064

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The broad line region in quasars and in the nuclei of active galaxies is the site of remarkable hydrodynamic activity unprecedented elsewhere in the universe. Considerable theoretical effort has been directed to determine how this intense radiation is related to high velocity gas motions in these small regions, which, because of their great distances, cannot be resolved by direct observation. A better theoretical understanding of the nature of the broad line-emitting gas involves many novel aspects of radiation hydrodynamics and may eventually provide insights into the nature of the mysterious quasar phenomenon itself.

Continuum and emission line properties of active galaxies and quasars are sufficiently similar that there is little doubt that both can be accounted for by a similar or closely related physical model. The main difference is one of luminosity; typical quasars are considerably brighter than Seyfert galaxies.

In the discussion below the relevant observations of quasars and active galaxies are briefly reviewed with an emphasis on the physical properties of the line-emitting gas and its immediate environment. Arguments that support the importance of radiation forces in producing the observed gas velocities are summarized. Finally, the nature of the acceleration process is described with particular attention paid to the various instabilities that may be present and which are generally characteristic of situations in which plasma velocities result directly from the deposition of radiative momentum. In fact, these troublesome instabilities suggest that radiative forces, although very strong, may provide only a partial explanation of the gasdynamical activity observed.

Type
7. Active Galactic Nuclei
Information
International Astronomical Union Colloquium , Volume 89: Radiation Hydrodynamics in Stars and Compacts Objects , 1986 , pp. 346 - 368
Copyright
Copyright © Springer-Verlag 1986

References

1. Wills, B.J., Netzer, H., and Wills, D. 1985, Ap. J., 288, 94.CrossRefGoogle Scholar
2. Netzer, H. 1985, Ap. J., 289, 451.Google Scholar
3. Shields, G.A. 1978, Nature, 272, 706.Google Scholar
4. Malkan, M.A., and Sargent, W.L.W. 1982, Ap. J., 254, 22.Google Scholar
5. Malkan, M.A. 1983, Ap. J. (Letters), 264, L1.Google Scholar
6. Davidson, K., and Netzer, H. 1979, Rev. Mod. Phys., 51, 715.Google Scholar
7. Kwan, J., and Krolik, J.H. 1981, Ap. J., 250, 478.CrossRefGoogle Scholar
8. Kwan, J. 1984, Ap. J., 283, 70.CrossRefGoogle Scholar
9. Gaskell, C.M. 1982, Ap. J., 263, 79.CrossRefGoogle Scholar
10. Wilkes, B.J. 1984, Mon. Not. Roy. Astron. Soc., 207, 73.Google Scholar
11. Mathews, W.G., and Wampler, E.J. 1985, Publ. Astron. Soc. Pac., in press.Google Scholar
12. Colin-Souffnn, S., Dumont, S., Heidmann, N., and Joly, M. 1980, Astron. Ap.., 83, 190.Google Scholar
13. Colin-Souffrin, S., Dumont, S., and Tully, J. 1982, Astron. Ap.., 106, 362.Google Scholar
14. Clavel, J., and Joly, M. 1984, Astr. Ap.., 131, 87.Google Scholar
15. Mathews, W.G., Blumenthal, G.R., and Grandi, S.A. 1980, Ap. J., 235, 971.Google Scholar
16. Wu, C.-C., Boggess, A., and Gull, T.R. 1983, Ap. J., 266, 28.Google Scholar
17. Reichert, G.A., Mushotzky, R.F., Petre, R., and Holt, S.S. 1985, Ap. J., in press.Google Scholar
18. Holt, S.S., Mushotzky, R.F., Becker, R.H., Boldt, E.A., Serlemitsos, P.J., Szymkowiak, A.E., and White, N.E. 1980, Ap. J. (Letters), 241, L13.Google Scholar
19. Ives, J.C., Sanford, P.W., and Penston, M.V. 1976, Ap. J., (Letters), 207, L159.Google Scholar
20. Mathews, W.G. 1967, Ap. J., 258, 425.Google Scholar
21. Mathews, W.G. 1985, Ap. J., submitted.Google Scholar
22. Junkkarinen, V.T., Burbidge, E.M., and Smith, H.E. 1983, Ap. J., 265, 51.Google Scholar
23. McKee, C.F., and Tarter, C.B. 1975, Ap. J., 202, 306.Google Scholar
24. Blumenthal, G.B., and Mathews, W.G. 1975, Ap. J., 198, 517.Google Scholar
25. Blumenthal, G.B., and Mathews, W.G. 1979, Ap. J., 233, 479.Google Scholar
26. Mathews, W.G. 1967, Ap. J., 147, 965.Google Scholar
27. Levich, E.V., and Sunyaev, R.A. 1970, Astroph. Letters, 7, 69.Google Scholar
28. Levich, E.V., and Sunyaev, R.A. 1971, Sov. Astron. Jour., 15, 363.Google Scholar
29. McCray, R.A. 1979, in Active Galactic Nuclei ed. Hazard., C.R. and Mitton, S.A. (Cambridge: Cambridge University Press).Google Scholar
30. Krolik, J.H., McKee, C.F. and Tartar, C.B. 1981, Ap. J., 249, 422.Google Scholar
31. Begelman, M.C., McKee, C.F., and Shields, G.A. 1983, Ap. J., 271 70.Google Scholar
32. Capriotti, E., Foltz, C., and Byard, P. 1980, Ap. J., 241, 903.Google Scholar
33. Capriotti, E., Foltz, C., and Byard, P. 1981, Ap. J., 245, 396.Google Scholar
34. Weymann, R.J., Scott, J.S., Schiano, A.V.R., and Christiansen, W.A. 1980, it Ap. J., 262, 497.Google Scholar
35. Mathews, W.G. 1976, Ap. J., 207, 351.Google Scholar
36. Mestel, L., Moore, D.W., and Perry, J.J. 1976, Astron. Ap., 52, 203.Google Scholar
37. Hearn, A.G. 1972, Astr Ap., 19, 417.Google Scholar
38. Hearn, A.G. 1973, Astr. Ap., 23, 97.Google Scholar
39. Kippenhahn, R. 1977, Astr. Ap., 55, 125.Google Scholar
40. Mathews, W.G., and Blumenthal, G.R. 1977, Ap. J., 214, 10.Google Scholar
41. Weymaim, R.J. 1976, Ap. J., 208, 286.Google Scholar
43. Williams, R.E. 1972, Ap. J., 178, 105.Google Scholar
44. Krolik, J.H. 1977, Phys. Fluids, 20, 264.Google Scholar
44. Krolik, J.H. 1979, Ap. J., 228, 13.Google Scholar
45. Eilek, J.A. and Caroff, L.J. 1979, Ap. J., 233, 463.Google Scholar
46. Mathews, W.G. 1983, Ap. J., 272, 390.Google Scholar
47. Verbunt, F., Fabma, A.C., and Rees, M.J. 1984, Nature, 309, 331.Google Scholar
48. Ferland, G.J. and Elitzur, M. 1984, Ap. J. (Letters), 285, L11.Google Scholar
49. Shields, G.A., and McKee, C.F. 1981, Ap. J. (Letters), 246, L57.Google Scholar