Evolutionary sequence of Seyfert galaxies

  • David L. Blank
  • Noam Soker
VII. Cosmological and Evolutionary Considerations
Part of the Lecture Notes in Physics book series (LNP, volume 307)

Abstract

We suggest that there exists an evolutionary sequence from Seyfert 2 to Seyfert 1 galaxies. We review observations which support this suggestion and the idea that the main parameter is the dust content in and around the Broad Line Region (BLR). We propose that Seyfert 2 galaxies evolve into Seyfert 1 Galaxies by expelling the dust from the BLR. It is further supposed that the dust is due to the interaction of the host galaxy with a second galaxy. The amount of dust needed is less than that found in a typical spiral galaxy.

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References

  1. Antonucci,.R.J., and Miller, J.S. 1985, Ap. J., 297, 621.Google Scholar
  2. Byrd, G.G., Sundelius, B., and Valtonen, M. 1987 Astr. Ap., 171, 16.Google Scholar
  3. Dahari, 0. 1984, Ph.D. thesis, University of California, Santa Cruz.Google Scholar
  4. Edelson, R.A., and Malkan, M.A., and Rieke, G.H. 1987, Ap. J., 321, 233.Google Scholar
  5. Ferland, G.J., and Netzer, N. 1983, Ap. J., 264, 105.Google Scholar
  6. Heckman, T.M. 1983, Ap. J., 268, 628.Google Scholar
  7. Keel, W.C., Kennicutt, R.C., Hummel, E., and Van Der Hulst, J.M. 1985, Astr. J., 90, 708.Google Scholar
  8. Krolik, J.H., and Begelman M.C. 1987, Ap. J., in press.Google Scholar
  9. Lawrence, A. 1987, Pub.A.S.P., 99, 309.Google Scholar
  10. Neugebauer, G., Becklin, E.E., Oke, J.B., and Searle, L. 1976, Ap. J., 230, 79.Google Scholar
  11. Rowan-Robinson, M. 1977, Ap. J., 213, 635.Google Scholar
  12. Sanders, D.B., Soifer, B.T., Elias, J.H., Madore, B.F., Matthews, K., Neugebauer, G., and Scoville, N.Z. 1988, Ap. J., (in press).Google Scholar
  13. Ulvestad, J.S., and Wilson, A.S. 1984, Ap. J., 278, 544.Google Scholar
  14. Whittle, M. 1985, M. N. R. A. S., 216, 817.Google Scholar
  15. Wilson, A.S., and Willis, A.G. 1980, Ap. J., 240, 429.Google Scholar

Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • David L. Blank
    • 1
  • Noam Soker
    • 1
  1. 1.Department of AstronomyUniversity of VirginiaCharlottesvilleUSA

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