Hostname: page-component-78c5997874-mlc7c Total loading time: 0 Render date: 2024-11-02T21:21:08.043Z Has data issue: false hasContentIssue false

Low-Luminosity Active Galactic Nuclei

Published online by Cambridge University Press:  07 August 2017

Alexei V. Filippenko*
Affiliation:
Department of Astronomy, University of California, Berkeley, CA 94720, U.S.A.

Abstract

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.

I review the basic properties of low-luminosity active galactic nuclei (LLAGNs) — objects in which activity similar to, but intrinsically milder than, that in QSOs and luminous Seyferts is believed to be present. Until recently, most LLAGNs were first recognized as such and studied at optical wavelengths, but evidence for activity and valuable information concerning its nature are now also being obtained in many other spectral ranges. Low-ionization nuclear emission-line regions (LINERs) are the most common LLAGNs; in a large fraction of them the emission lines come from clouds of gas probably photoionized by a nonstellar continuum, rather than heated by shocks. It is also clear, however, that there could be substantial heterogeneity among LINERs, particularly those with extended emission; some may be produced by cooling flows, supernova-driven winds, and galaxy interactions or mergers. LLAGNs can easily be hidden from sight in a variety of ways, including obscuration by galactic or circumnuclear disks and dilution by bursts of star formation. Direct imaging, spectroscopy, and spectropolarimetry can be used to isolate the different components, especially with high spatial and/or spectral resolution. A surprising result is that Seyfert nuclei are sometimes found in dwarf and very late-type galaxies. The nearby Sd III-IV galaxy NGC 4395 contains the intrinsically faintest known Seyfert 1 nucleus, with a broad Ha luminosity only ∼ 0.1 that of M81. The idea that the apparent “activity” in some galaxies is a direct consequence of vigorous star formation has some strong supporting evidence, and should seriously be considered. As an example, I focus on the peculiar supernova 1987F, whose optical spectrum bears a striking resemblance to that of typical Seyfert 1 nuclei.

Type
Part 9: Intrinsically Weak AGNs
Copyright
Copyright © Kluwer 1989 

References

Adams, T. F., and Weedman, D. W. 1975, Ap. J., 199, 19.CrossRefGoogle Scholar
Aldrovandi, S. M. V., and Contini, M. 1984, Astr. Ap., 140, 368.Google Scholar
Antonucci, R. R. J. 1983, Nature, 303, 158.CrossRefGoogle Scholar
Antonucci, R. R. J., and Miller, J. S. 1985, Ap. J., 297, 621.CrossRefGoogle Scholar
Baldwin, J. A., Phillips, M. M., and Terlevich, R. 1981, Pub. A.S.P., 93, 5 (BPT).CrossRefGoogle Scholar
Barr, P., Giommi, P., Wamsteker, W., Gilmozzi, R., and Mushotzky, R. F. 1985, Bull. A.A.S., 17, 608.Google Scholar
Bartel, N., Ratner, M., Shapiro, I., and Rogers, A. 1987, in IAU Symposium 121: Observational Evidence of Activity in Galaxies, ed. Khachikian, E. Ye., Fricke, K. J., and Melnick, J. (Dordrecht: Reidel), p. 521.CrossRefGoogle Scholar
Begelman, M. C., and Sarazin, C. L. 1986, Ap. J. (Letters), 302, L59.CrossRefGoogle Scholar
Binette, L. 1985, Astr. Ap., 143, 334.Google Scholar
Boroson, T. A., and Oke, J. B. 1982, Nature, 296, 397.CrossRefGoogle Scholar
Bruzual, A. G., Peimbert, M., and Torres-Peimbert, S. 1982, Ap. J., 260, 495.CrossRefGoogle Scholar
Burbidge, E. M., and Burbidge, G. R. 1962, Ap. J., 135, 694.CrossRefGoogle Scholar
Carswell, R. F., Baldwin, J. A., Atwood, B., and Phillips, M. M. 1984, Ap. J., 286, 464.CrossRefGoogle Scholar
Chevalier, R. A., and Clegg, A. W. 1985, Nature, 317, 44.CrossRefGoogle Scholar
Condon, J. J., and Dressel, L. L. 1978, Ap. J., 221, 456.CrossRefGoogle Scholar
Crane, P. C., Giuffrida, T. S., and Carlson, J. B. 1976, Ap. J. (Letters), 203, L113.CrossRefGoogle Scholar
de Grijp, M. H. K., Miley, G. K., Lub, J., and de Jong, T. 1985, Nature, 314, 240.CrossRefGoogle Scholar
Diaz, A. I., Pagel, B. E., and Terlevich, E. 1985, M.N.R.A.S., 214, 41P.CrossRefGoogle Scholar
di Serego Alighieri, S., Binette, L., Courvoisier, T. J.-L., Fosbury, R. A. E., and Tadhunter, C. N. 1988, Nature, 334, 591.CrossRefGoogle Scholar
Dopita, M. A. 1977, Ap. J. Suppl., 33, 437.CrossRefGoogle Scholar
Dressler, A. 1989, these Proceedings. Google Scholar
Edmunds, M. G., and Pagel, B. E. J. 1982, M.N.R.A.S., 198, 1089.CrossRefGoogle Scholar
Ellis, R. S., Gondhalekar, P. M., and Efstathiou, G. 1982, M.N.R.A.S., 201, 223.CrossRefGoogle Scholar
Elvis, M. 1984, Adv. Space Res., 3, No. 10–12, 207.CrossRefGoogle Scholar
Elvis, M., and Van Speybroeck, L. 1982, Ap. J. (Letters), 257, L51.CrossRefGoogle Scholar
Fabbiano, G., 1986, Pub. A.S.P., 98, 525.CrossRefGoogle Scholar
Fabian, A. C., Arnaud, K. A., Nulsen, P. E. J., and Mushotzky, R. F. 1986, Ap. J., 305, 9.CrossRefGoogle Scholar
Ferland, G. J., and Netzer, H. 1983, Ap. J., 264, 105.CrossRefGoogle Scholar
Ferland, G. J., and Shields, G. A. 1985, in Astrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J. S. (Mill Valley, CA: University Science Books), p. 157.Google Scholar
Filippenko, A. V. 1984, , California Institute of Technology (Ann Arbor: University Microfilms International).Google Scholar
Filippenko, A. V. 1985, Ap. J., 289, 475.CrossRefGoogle Scholar
Filippenko, A. V. 1988, in Supermassive Black Holes, ed. Kafatos, M. (Cambridge: Cambridge University Press), p. 104.Google Scholar
Filippenko, A. V. 1989, A.J., submitted.Google Scholar
Filippenko, A. V., and Halpern, J. P. 1984, Ap. J., 285, 458.CrossRefGoogle Scholar
Filippenko, A. V., and Sargent, W. L. W. 1985, Ap. J. Suppl., 57, 503 (FS85).CrossRefGoogle Scholar
Filippenko, A. V., and Sargent, W. L. W. 1986, in Structure and Evolution of Active Galactic Nuclei, ed. Giuricin, G. et al. (Dordrecht: Reidel), p. 21 (FS86).CrossRefGoogle Scholar
Filippenko, A. V., and Sargent, W. L. W. 1988, Ap. J., 324, 134 (FS88).CrossRefGoogle Scholar
Filippenko, A. V., and Sargent, W. L. W. 1989a, in preparation.Google Scholar
Filippenko, A. V., and Sargent, W. L. W. 19896, in preparation.Google Scholar
Ford, H. C., and Butcher, H. 1979, Ap. J. Suppl., 41, 147.CrossRefGoogle Scholar
Fosbury, R. A. E., Mebold, U., Goss, W. M., and Dopita, M. A. 1978, M.N.R.A.S., 183, 549.CrossRefGoogle Scholar
Fosbury, R. A. E., Mebold, U., Goss, W. M., and van Woerden, H. 1977, M.N.R.A.S., 179, 89.CrossRefGoogle Scholar
Fosbury, R. A. E., Snijders, M. A. J., Boksenberg, A., and Penston, M. V. 1981, M.N.R.A.S., 197, 235.CrossRefGoogle Scholar
Fosbury, R. A. E., and Wall, J. V. 1979, M.N.R.A.S., 189, 79.CrossRefGoogle Scholar
Goodrich, R. W., and Keel, W. C. 1986, Ap. J., 305, 148.CrossRefGoogle Scholar
Halpern, J. P., and Steiner, J. E. 1983, Ap. J. (Letters), 269, L37.CrossRefGoogle Scholar
Heckman, T. M. 1980, Astr. Ap., 87, 152.Google Scholar
Heckman, T. M. 1987, in IAU Symposium 121: Observational Evidence of Activity in Galaxies, ed. Khachikian, E. Ye., Fricke, K. J., and Melnick, J. (Dordrecht: Reidel), p. 421.CrossRefGoogle Scholar
Hu, E. M., Cowie, L. L., and Wang, Z. 1985, Ap. J. Suppl., 59, 447.CrossRefGoogle Scholar
Hutchings, J. B., and Craven, S. E. 1988, A.J., 95, 677.CrossRefGoogle Scholar
Jones, D. L., Sramek, R. A., and Terzian, Y. 1981, Ap. J., 246, 28.CrossRefGoogle Scholar
Keel, W. C. 1983, Ap. J., 269, 466.CrossRefGoogle Scholar
Keel, W. C. 1984, Ap. J., 282, 75.CrossRefGoogle Scholar
Keel, W. C. 1985, in Astrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J. S. (Mill Valley, CA: University Science Books), p. 1.Google Scholar
Keel, W. C., and Miller, J. S. 1983, Ap. J. (Letters), 266, L89.CrossRefGoogle Scholar
Kellermann, K. I., Shaffer, D. B., Pauliny-Toth, I. I. K., Preuss, E., and Witzel, A. 1976, Ap. J. (Letters), 210, L121.CrossRefGoogle Scholar
Kennicutt, R. C. Jr., Keel, W. C., and Blaha, C. A. 1989, preprint.Google Scholar
Kent, S. M., and Sargent, W. L. W. 1979, Ap. J., 230, 667.CrossRefGoogle Scholar
Khachikian, E. Ye. 1989, these Proceedings. Google Scholar
Khachikian, E. Ye., and Weedman, D. W. 1971, Astrofizika, 7, 389.Google Scholar
Koski, A. T. 1978, Ap. J., 223, 56.CrossRefGoogle Scholar
Koski, A. T., and Osterbrock, D. E. 1976, Ap. J. (Letters), 203, L49.CrossRefGoogle Scholar
Kronberg, P. P., Biermann, P., and Schwab, F. R. 1985, Ap. J., 291, 693.CrossRefGoogle Scholar
Kunth, D., Sargent, W. L. W., and Bothun, G. D. 1987, A.J., 93, 29.CrossRefGoogle Scholar
Lawrence, A. 1987, Pub. A.S.P., 99, 309.CrossRefGoogle Scholar
Lawrence, A., and Elvis, M. 1982, Ap. J., 256, 410.CrossRefGoogle Scholar
Lequeux, J. 1979, Astr. Ap., 80, 35.Google Scholar
Maccacaro, T., Gioia, I. M., Schild, R., Maccagni, D., and Stocke, J. 1987, in IAU Symposium 121: Observational Evidence of Activity in Galaxies, ed. Khachikian, E. Ye., Fricke, K. J., and Melnick, J. (Dordrecht: Reidel), p. 469.CrossRefGoogle Scholar
McCarthy, P. J., Heckman, T., and van Breugel, W. 1987, A.J., 93, 264.CrossRefGoogle Scholar
Miller, J. S. 1989, these Proceedings. Google Scholar
Mushotzky, R. F. 1982, Ap. J., 256, 92.CrossRefGoogle Scholar
Niemela, V. S., Ruíz, M. T., and Phillips, M. M. 1985, Ap. J., 289, 52.CrossRefGoogle Scholar
Norris, R. P. 1989, these Proceedings. CrossRefGoogle Scholar
O'Connell, R. W., and Dressel, L. L. 1978, Nature, 276, 374.CrossRefGoogle Scholar
Oke, J. B., and Searle, L. 1974, Ann. Rev. Astr. Ap., 12, 315.CrossRefGoogle Scholar
Osterbrock, D. E. 1977, Ap. J., 215, 733.CrossRefGoogle Scholar
Osterbrock, D. E. 1981, Ap. J., 249, 462.CrossRefGoogle Scholar
Osterbrock, D. E., and Dahari, O. 1983, Ap. J., 273, 478.CrossRefGoogle Scholar
Peimbert, M., and Torres-Peimbert, S. 1981, Ap. J., 245, 845.CrossRefGoogle Scholar
Péquignot, D. 1984, Astr. Ap., 131, 159.Google Scholar
Persson, S. E. 1988, Ap. J., 330, 751.CrossRefGoogle Scholar
Peterson, B. M., and Ferland, G. J. 1986, Nature, 324, 345.CrossRefGoogle Scholar
Phillips, M. M. 1981, M.N.R.A.S., 197, 659.CrossRefGoogle Scholar
Phillips, M. M., Charles, P. A., and Baldwin, J. A. 1983, Ap. J., 266, 485.CrossRefGoogle Scholar
Phillips, M. M., Jenkins, C. R., Dopita, M. A., Sadler, E. M., and Binette, L. 1986, A.J., 91, 1062.CrossRefGoogle Scholar
Pogge, R. W. 1988a, Ap. J., 328, 519.CrossRefGoogle Scholar
Pogge, R. W. 1988b, Ap. J., 332, in press.CrossRefGoogle Scholar
Reichert, G. A., Wu, C.-C., and Filippenko, A. V. 1988, in A Decade of UV Astronomy with the IUE Satellite, ed. Rolfe, E. J. (Noordwijk: ESA Publication Division), 2, 307.Google Scholar
Rieke, G. H., Cutri, R. M., Black, J. H., Kailey, W. F., McAlary, C. W., Lebofsky, M. J., and Elston, R. 1985, Ap. J., 290, 116.CrossRefGoogle Scholar
Rieke, G. H., Lebofsky, M. J., and Kemp, J. C. 1982, Ap. J. (Letters), 252, L53.CrossRefGoogle Scholar
Rose, J. A., and Searle, L. 1982, Ap. J., 253, 556.CrossRefGoogle Scholar
Rose, J. A., and Tripicco, M. J. 1984, Ap. J., 285, 55.CrossRefGoogle Scholar
Sadler, E. M. 1987, in IAU Symposium 121: Observational Evidence of Activity in Galaxies, ed. Khachikian, E. Ye., Fricke, K. J., and Melnick, J. (Dordrecht: Reidel), p. 443.CrossRefGoogle Scholar
Sandage, A. 1978, A. J., 83, 904.CrossRefGoogle Scholar
Sanders, D. B., Soifer, B. T., Elias, J. H., Madore, B. F., Matthews, K., Neugebauer, G., and Scoville, N. Z. 1988, Ap. J., 325, 74.CrossRefGoogle Scholar
Schaeffer, R. Cassé, M., and Cahen, S. 1987, Ap. J. (Letters), 316, L31.CrossRefGoogle Scholar
Shapiro, S. L., and Teukolsky, S. A. 1986, Ap. J., 307, 575.CrossRefGoogle Scholar
Shields, J. C., and Filippenko, A. V. 1988, Ap. J. (Letters), 332, L55.CrossRefGoogle Scholar
Shields, J. C., and Filippenko, A. V. 1989, these Proceedings. Google Scholar
Shuder, J. M. 1980, Ap. J., 240, 32.CrossRefGoogle Scholar
Shuder, J. M. 1981, Ap. J., 244, 12.CrossRefGoogle Scholar
Shuder, J. M., and Osterbrock, D. E. 1981, Ap. J., 250, 55.CrossRefGoogle Scholar
Shull, J. M., and McKee, C. F. 1979, Ap. J., 227, 131.CrossRefGoogle Scholar
Stasińska, G. 1984, Astr. Ap., 135, 341.Google Scholar
Stauffer, J. R. 1982, Ap. J., 262, 66.CrossRefGoogle Scholar
Stone, J. L. Jr., Wilson, A. S., and Ward, M. J. 1988, Ap. J., 330, 105.CrossRefGoogle Scholar
Tadhunter, C. N., Fosbury, R. A. E., Binette, L., Danziger, I. J., and Robinson, A. 1987, Nature, 325, 504.CrossRefGoogle Scholar
Terlevich, R., and Melnick, J. 1985, M.N.R.A.S., 213, 841.CrossRefGoogle Scholar
Terlevich, R., and Melnick, J. 1988a, in Starbursts and Galaxy Evolution, ed. Thuan, T. X., Montmerle, T., and Tran Thanh Van, J. (Éditions Frontières, France), p. 393.Google Scholar
Terlevich, R., and Melnick, J. 1988b, Nature, 333, 239.CrossRefGoogle Scholar
Terlevich, R., Melnick, J., and Moles, M. 1987, in IAU Symposium 121: Observational Evidence of Activity in Galaxies, ed. Khachikian, E. Ye., Fricke, K. J., and Melnick, J. (Dordrecht: Reidel), p. 499 (TMM).CrossRefGoogle Scholar
van der Hulst, J. M., Crane, P. C., and Keel, W. C. 1981, A.J., 86, 1175.CrossRefGoogle Scholar
Veilleux, S., and Osterbrock, D. E. 1987, Ap. J. Suppl., 63, 295.CrossRefGoogle Scholar
Véron, P. 1979, Astr. Ap., 78, 46.Google Scholar
Véron, P., Lindblad, P. O., Zuiderwijk, E. J., Véron, M. P., and Adam, G. 1980, Astr. Ap., 87, 245.Google Scholar
Véron, P., Véron, M. P., Bergeron, J., and Zuiderwijk, E. J. 1981, Astr. Ap., 97, 71.Google Scholar
Véron-Cetty, M.-P., and Véron, P. 1986, Astr. Ap. Suppl., 66, 335.Google Scholar
Weedman, D. W. 1985, in Astrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J. S. (Mill Valley, CA: University Science Books), p. 497.Google Scholar
Whittle, M. 1985, M.N.R.A.S., 216, 817.CrossRefGoogle Scholar
Whittle, M. 1989, these Proceedings. Google Scholar
Whittle, M., Pedlar, A., Meurs, E. J. A., Unger, S. W., Axon, D. J., and Ward, M. J. 1988, Ap. J., 326, 125.CrossRefGoogle Scholar
Wilson, A. S., and Heckman, T. M. 1985, in Astrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J. S. (Mill Valley, CA: University Science Books), p. 39.Google Scholar
Wilson, A. S., Ward, M. J., and Haniff, C. A. 1988, Ap. J., 334, 121.CrossRefGoogle Scholar
Wrobel, J. M. 1989, these Proceedings. Google Scholar
Wunderlich, E., Klein, U., and Wielebinski, R. 1987, Astr. Ap. Suppl., 69, 487.Google Scholar
Yee, H. K. C. 1980, Ap. J., 241, 894.CrossRefGoogle Scholar
Yee, H. K. C., and De Robertis, M. M. 1989, these Proceedings. Google Scholar
Yee, H. K. C., and Green, R. F. 1987, Ap. J., 319, 28.CrossRefGoogle Scholar