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Towards a Truly Unified Model of AGN: Aspect, Accretion and Evolution

Published online by Cambridge University Press:  05 March 2013

Michael A. Dopita*
Affiliation:
Mt Stromlo and Siding Spring Observatories, Institute of Advanced Studies, Australian National University, Private Bag, Weston Creek PO, ACT 2611, Australia; [email protected]
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Abstract

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The Unified Model holds that the aspect-dependent effects primarily determine the nature of the active galactic nucleus that we observe. In this paper, I argue that three parameters; aspect, accretion rate into the nuclear regions, and the evolutionary status of the central black hole hold the key to unification. The mystery of why the epoch of quasar formation occurred so early in the evolution of the Universe, why radio-loud QSOs represent only a small fraction of the general population of QSOs, and why ellipticals are invariably the hosts of radio-loud active galaxies could be explained if (a) the most rapid growth of black holes occurred in galactic merger events, and if (b) an excess in the rate of nuclear feeding was able to choke off the radio jets, producing radio quiet QSOs. In this paper, I develop the idea that rate of nuclear feeding plays a dominant role and that feeding at super-Eddington rates into the broad-line region (BLR) during merger events is the means whereby massive black holes are grown. In particular, I develop a toy model for the radio-loud, radio-quiet dichotomy based on the rate of nuclear feeding, suggest an electron scattering model for the ‘big blue bump’ and its relation to the BLR, and emphasise the important diagnostic capabilities offered by analyses of the narrow line regions based on shock excitation models.

Type
Research Article
Copyright
Copyright © Astronomical Society of Australia 1997

References

Abbott, D. C., & Conti, P. S. 1987, ARA&A, 25, 113 Google Scholar
Antonucci, R. 1993, ARA&A, 31, 473 Google Scholar
Antonucci, R., & Miller, J. S. 1985, ApJ, 297, 621 CrossRefGoogle Scholar
Armus, L., Heckman, T. M., & Miley, G. K. 1989, ApJ, 347, 727 CrossRefGoogle Scholar
Armus, L., Heckman, T. M., & Miley, G. K. 1990, ApJ, 364, 471 CrossRefGoogle Scholar
Bahcall, J. N., Kirhakos, S., Saxe, D. H., & Schneider, D. P. 1997, ApJ, 479, 642 CrossRefGoogle Scholar
Baldwin, J. A. 1977, ApJ, 214, 679 CrossRefGoogle Scholar
Baldwin, J. A., Wampler, E. J., & Gaskell, C. M. 1978, Nature, 273, 431 CrossRefGoogle Scholar
Barnes, J. E., & Hernquist, L. 1991, ApJ, 370, 65 CrossRefGoogle Scholar
Barnes, J. E., & Hernquist, L. 1992, ARA&A, 30, 705 Google Scholar
Barnes, J. E., & Hernquist, L. 1996, ApJ, 471, 115 CrossRefGoogle Scholar
Barthel, P. D. 1981, Adv. Space Research, 11, 231 CrossRefGoogle Scholar
Barvainis, R., Lonsdale, C., & Antonucci, R. 1996, AJ, 111, 1431 CrossRefGoogle Scholar
Baum, S. A., Zirbel, E. I., & O'Dea, C. P. 1995, ApJ, 451, 88 CrossRefGoogle Scholar
Begelman, M. C. 1996, in Cygnus A: Study of a Radio Galaxy, ed. C. L. Carilli & D. A. Harris (Cambridge Univ. Press), 209 Google Scholar
Bekki, K. 1995, MNRAS, 276, 9 Google Scholar
Bicknell, G. V. 1994, ApJ, 442, 542 CrossRefGoogle Scholar
Bicknell, G. V., & Begelman, M. C. 1996, ApJ, 467, 597 CrossRefGoogle Scholar
Bicknell, G.V, Dopita, M. A., & O'Dea, C. 1997, ApJ 485, 41 CrossRefGoogle Scholar
Blandford, R. D. 1990, in Active Galactic Nuclei, ed. T. J. -L., & M. Mayor, Saas-Fee Advanced Course 20 (Berlin: Springer), 161 CrossRefGoogle Scholar
Blandford, R. D., & Konigl, A. 1979, ApJ, 232, 34 CrossRefGoogle Scholar
Blandford, R. D., & Rees, M. J. 1978, in Pittsburgh Conference on BL Lac Objects, ed. A. N. Wolfe (Univ. Pittsburg Press), 328 Google Scholar
Bondi, H., & Hoyle, F. 1944, MNRAS, 104, 273 CrossRefGoogle Scholar
Boyce, P. J., Disney, M. J., Blades, J. C., Boksenberg, A., Crane, P., Deharveng, J. M., Maccetto, F. D., Mackay, C. D., & Sparks, W. B. 1996, ApJ, 473, 760 CrossRefGoogle Scholar
Chiang, J., & Murray, N. 1996, ApJ, 466, 704 CrossRefGoogle Scholar
Cowie, L. L., Hu, E. M., Jenkins, E. B., & York, D. G. 1983, ApJ, 272, 29 CrossRefGoogle Scholar
Dopita, M. A., & Sutherland, R. S. 1995, ApJ, 455, 468 CrossRefGoogle Scholar
Dopita, M. A., Heisler, C. A., Lumsden, S. L., & Bailey, J. A. 1997 a, ApJ (submitted)Google Scholar
Dopita, M. A., Koratkar, A. P., Allen, M. G., Tsevetanov, Z. I., Ford, H. C., Bicknell, G. V., & Sutherland, R. S. 1997 b, ApJ (in press)Google Scholar
Falcke, H., & Biermann, P. L. 1995, A&A, 293, 665 Google Scholar
Falcke, H., Malkan, M. A., & Biermann, P. L. 1995, A&A, 298, 375 Google Scholar
Fanti, R., Fanti, C., Schilizzi, R. T., Spencer, R. E., Nan, Redong, Parma, P., van Breugel, W. J. M., & Venturi, T. 1990, A&A, 231, 333 Google Scholar
Fanti, C., Fanti, R., Dallacasa, D., Schilizzi, R. T., Spencer, R. E., & Stanghellini, C. 1995, A&A, 302, 317 Google Scholar
Ferland, G. J., & Netzer, H. 1983, ApJ, 264, 105 CrossRefGoogle Scholar
Ford, H. C., et al. 1994, ApJ, 435, L27 CrossRefGoogle Scholar
Fosbury, R. A. E., Mebold, U., Goss, W. M., & Dopita, M. A. 1978, MNRAS, 183, 549 CrossRefGoogle Scholar
Gelderman, R. 1995, PASP, 107, 205 CrossRefGoogle Scholar
Gelderman, R., & Whittle, M. 1994, ApJS, 91, 491 CrossRefGoogle Scholar
Heckman, T. M. 1980, A&A, 87, 142 Google Scholar
Heckman, T. M. 1981, ApJ, 250, L59 CrossRefGoogle Scholar
Heckman, T. M., Baum, S. A., van Breugel, W. J. M., & McCarthy, P. 1989, ApJ, 338, 48 CrossRefGoogle Scholar
Heisler, C. A., Lumsden, S. L., & Bailey, J. A. 1997, Nature, 385, 700 CrossRefGoogle Scholar
Ho, L. C., Fillipenko, A. V., & Sargent, W. L. 1995, ApJS, 98, 477 CrossRefGoogle Scholar
Hutchings, J. B., & Neff, S. G. 1992, AJ, 104, 1 CrossRefGoogle Scholar
Johnstone, R. M., Fabian, A. C., & Nulsen, P. E. J. 1987, MNRAS, 224, 74 CrossRefGoogle Scholar
Kim, D.-C. 1995, PhD Thesis, University of Hawaii Google Scholar
Kinney, A. L., Rivolo, A. R., & Koratkar, A. P. 1990, ApJ, 357, 338 CrossRefGoogle Scholar
Kormendy, J., & Sanders, D. B. 1992, ApJ, 390, L53 CrossRefGoogle Scholar
Koski, A. T. 1978, ApJ, 223, 56 CrossRefGoogle Scholar
Koski, A. T., & Osterbrock, D. E. 1976, ApJ, 203, L49 CrossRefGoogle Scholar
Lawrence, A. 1987, PASP, 99, 309 CrossRefGoogle Scholar
Lawrence, A., & Elvis, M. 1982, ApJ, 256, 410 CrossRefGoogle Scholar
Lonsdale, C. L., Smith, H. E., & Lonsdale, C. J. 1995, ApJ, 438, 632 CrossRefGoogle Scholar
McCarthy, P. J., Spinrad, H., & van Breugel, W. 1995, ApJ, 447, 77 Google Scholar
Maoz, D. 1994, in Reverberation Mapping of the Broad-line Region in Active Galactic Nuclei, ed. P. M. Gondhalekar K. Horne & B. M. Peterson, ASP Conf. Ser. 69, 95 Google Scholar
Meisenheimer, K., Hippelein, H., & Neeser, M. 1994, in The First Stromlo Symposium: The Physics of Active Galaxies, ed. G. V. Bicknell M. A. Dopita & P. J. Quinn, ASP Conf. Ser. 54, 397 Google Scholar
Melnick, J., & Mirabel, I. F. 1990, A&A, 231, L19 Google Scholar
Murray, N., & Chiang, J. 1995, ApJ, 459, L105 Google Scholar
Murray, N., Chiang, J., Grossman, S. A., & Voit, G. M. 1995, ApJ, 451, 498 CrossRefGoogle Scholar
Mushotzky, R. F., Done, C., & Pounds, K. A. 1993, ARA&A, 31, 717 Google Scholar
Nelson, C. H., & Whittle, M. 1996, ApJ, 465, 96 CrossRefGoogle Scholar
O'Dea, C. P., Baum, S. A., Staghellini, C., Morris, G. B., Patnaik, A. R., & Gopal-Krishna, 1990, A&A Suppl. Ser., 84, 549 Google Scholar
Orr, M. J. L., & Browne, I. W. A. 1982, MNRAS, 200, 1067 CrossRefGoogle Scholar
Owen, F. N., & Ledlow, M. J. 1994, in The First Stromlo Symposium: The Physics of Active Galaxies, ed. G. V. Bicknell M. A. Dopita & P. J. Quinn, ASP Conf. Ser. 54, 319 Google Scholar
Petrich, L. I., Shapiro, S. L., & Teukolsky, S. A. 1988, Phys. Rev. Lett., 60, 1781 CrossRefGoogle Scholar
Petrich, L. I., Shapiro, S. L., Stark, R. F., & Teukolsky, S. A. 1989, ApJ, 336, 313 CrossRefGoogle Scholar
Phillips, M. A., Jenkins, C. R., Dopita, M. A., Sadler, E. M., & Binette, L. 1986, AJ, 91, 1062 CrossRefGoogle Scholar
Phillips, R. B., & Mutel, R. L. 1982, A&A, 106, 21 Google Scholar
Rees, M., Begelman, M., Blandford, R., & Phinney, E. 1982, Nature, 295, 17 CrossRefGoogle Scholar
Reynolds, C. S., Di Matteo, T., Fabian, A., Hwang, U., & Canizares, C. R. 1996, MNRAS, 283, L111 CrossRefGoogle Scholar
Rowan-Robinson, M. 1977, ApJ, 213, 638 CrossRefGoogle Scholar
Rowan-Robinson, M., et al. 1991, Nature, 351, 719 CrossRefGoogle Scholar
Rowan-Robinson, M., et al. 1993, MNRAS, 261, 513 CrossRefGoogle Scholar
Sanders, D. B., & Mirabel, I. F. 1996, ARA&A, 34, 749 Google Scholar
Schmidt, M., & Green, R. F. 1983, ApJ, 269, 352 CrossRefGoogle Scholar
Scoville, N. Z., Sargent, A. I., Sanders, D. B., & Soifer, B. T. 1991, ApJ, 336, L5 CrossRefGoogle Scholar
Shakura, N. I., and Sunyaev, R. A. 1973, A&A, 24, 337 Google Scholar
Shlosman, I., Frank, J., & Begelman, M. C. 1989, Nature, 338, 45 CrossRefGoogle Scholar
Simkin, S. M., Su, H. J., & Schwarz, M. P. 1980, ApJ, 237, 404 CrossRefGoogle Scholar
Smith, E. P., Heckman, T. M., Bothun, G. D., Romanishin, W., & Balick, B. 1986, ApJ, 306, 64 CrossRefGoogle Scholar
Solomon, P. M., Downes, D., & Radford, S. J. E. 1992, ApJ, 387, L55 CrossRefGoogle Scholar
Stasinska, G. 1984, A&A, 135, 341 Google Scholar
Urry, C. M., & Padovani, P. 1995, PASP, 107, 803 CrossRefGoogle Scholar
van Albada, T. S. 1982, MNRAS, 201, 939 CrossRefGoogle Scholar
van Ojik, R., Rottgering, H. J. A., Miley, G. K., Bemer, M. N., Maccetto, F., & Chambers, K. C. 1994, A&A, 289, 54 Google Scholar
Veilleux, S., Kim, D.-C., Sanders, D. B., Mazzarella, J. M., & Soifer, B. T. 1995, ApJS, 98, 171 CrossRefGoogle Scholar
Wilkinson, P. N., Polatdis, A. G., Readhead, A. C. S., Xu, W., & Pearson, T. J. 1994, ApJ, 432, L87 CrossRefGoogle Scholar
Wilson, A. S., & Colbert, E. J. M. 1995, ApJ, 438, 62 CrossRefGoogle Scholar
Wright, G. S., James, P. A., Joseph, R. D., & McLean, I. S. 1990, Nature, 344, 417 CrossRefGoogle Scholar
Wurtz, R., Stocke, J. T., Ellinson, E., & Yee, H. K. C. 1997, ApJ, 480, 547 CrossRefGoogle Scholar