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The Nature of Liners

Published online by Cambridge University Press:  04 August 2017

Timothy M. Heckman*
Affiliation:
Astronomy Program, University of Maryland, College Park, MD 20785, U.S.A.

Abstract

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LINER's (Low-Ionization Nuclear Emission-line Regions) are found in the majority of early-type (Sb or earlier) galaxies, and in some late-type and peculiar galaxies as well. Because they are so common but are not energized by normal stars, their nature is critical to our understanding of both the active galactic nucleus phenomenon and the evolution of normal galactic nuclei. After briefly reviewing the spectroscopic basis of the LINER classification, I summarize four alternative models for LINER's: 1) LINER's as “mini-Seyferts” in which the emission-line gas is photoionized by a more dilute version of the high-energy nonstellar continuum found in Seyfert nuclei. 2) LINER's as accretion flows of cooling gas originating in the halos of galaxies and/or in the intra-cluster medium. 3) LINER's as starburst-driven winds. 4) LINER's as colliding, shock-heated galaxies. After reviewing the evidence, I conclude that it is very likely that several (and possibly all) of the above models are needed to account for the diverse properties of LINER's. While LINER's would then not have a single unified explanation, they would have a direct bearing on many issues in extragalactic astronomy.

Type
VII. Low Level Activity and Intermediate Objects
Copyright
Copyright © Reidel 1987 

References

Axon, D.J., and Taylor, K. 1978, Nature, 274, 37.CrossRefGoogle Scholar
Baldwin, J.A., Phillips, M.M., and Terlevich, R. 1981, P.A.S.P., 93, 5.Google Scholar
Balick, B., and Heckman, T.M. 1982, Ann. Rev. Astr. Ap., 20, 431.CrossRefGoogle Scholar
Becklin, E. 1986, talk presented at the “Star Formation in Galaxies” conference, Caltech, June, 1986.Google Scholar
Biermann, P., and Kronberg, P. 1983, Ap. J. Lett., 268, L69.Google Scholar
Binette, L. 1985, Astr. Ap., 143, 334.Google Scholar
Binette, L., Dopita, M.A., and Tuohy, I.R. 1985, Ap. J., 297, 496.Google Scholar
Canizares, C.R., Stewart, G.C., and Fabian, A.C., 1983, Ap. J., 272, 449.Google Scholar
Carswell, R.F., Baldwin, J.A., Atwood, B., and Phillips, M.M. 1984, Ap. J., 286, 464.Google Scholar
Chevalier, R.A., and Clegg, A.W. 1985, Nature, 317, 5.Google Scholar
Costero, R., and Osterbrock, D.E. 1977, Ap. J., 211, 675.Google Scholar
Cowie, L.L., and Binney, J. 1977, Ap. J., 215, 723.Google Scholar
Cowie, L.L., Hu, E., Jenkins, E., and York, D. 1983, Ap. J., 272, 29.Google Scholar
Cowie, L.L., Fabian, A.C., and Nulsen, P.E. 1980, M.N.R.A.S., 191, 399.Google Scholar
DePoy, D.L., Becklin, E.E., and Wynn-Williams, C.G. 1986, Ap. J., in press.Google Scholar
Dopita, M.A. 1977, Ap. J. Suppl., 33, 437.Google Scholar
Evans, I.N., and Dopita, M.A. 1985, Ap. J. Suppl., 58, 125.Google Scholar
Fabian, A.C. et al. 1985, M.N.R.A.S., 216, 923.Google Scholar
Fabian, A.C., Nulsen, P.E.J., and Canizares, C.R. 1982, M.N.R.A.S., 201, 933.Google Scholar
Fabian, A.C., and Nulsen, P.E.J. 1977, M.N.R.A.S., 180, 479.Google Scholar
Fabian, A.C., Arnaud, K.A., Nulsen, P.E.J., and Mushotzky, R.F. 1986, Ap. J., 305, 9.Google Scholar
Fabbiano, G., and Trinchieri, G., 1984, Ap. J., 286, 491.Google Scholar
Ferland, G.J., and Netzer, H. 1983, Ap. J. 264, 105.Google Scholar
Filippenko, A.V., and Sargent, W.L.W. 1985, Ap. J. Suppl., 57, 503.Google Scholar
Filippenko, A.V., and Halpern, J.P. 1984, Ap. J., 285, 458.Google Scholar
Filippenko, A.V. 1985, Ap. J., 289, 475.Google Scholar
Ford, H.C., and Butcher, H.R. 1979, Ap. J. Suppl., 41, 147.CrossRefGoogle Scholar
Forman, W., Jones, C., and Tucker, W. 1985, Ap. J., 293, 102.Google 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., Snijders, M.A.J., Boksenberg, A., and Penston, M.V. 1981, M.N.R.A.S., 197, 235.Google 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.Google Scholar
Gunn, J.E. 1979, in “Active Galactic Nuclei”, ed. Hazard, C. and Mitton, S. (Cambridge University Press), p. 213.Google Scholar
Halpern, J.P., and Steiner, J.E. 1983, Ap. J. Lett., 269, L37.Google Scholar
Halpern, J.P., and Filippenko, A.V. 1984, Ap. J., 285, 475.Google Scholar
Harwit, M. 1986, Talk presented at the “Star Formation in Galaxies” conference, Caltech, June 1986.Google Scholar
Heckman, T.M. 1980, Astr. Ap., 87, 152.Google Scholar
Heckman, T.M., Balick, B., and Crane, P.C. 1980, Astr. Ap. Suppl., 40, 295.Google Scholar
Heckman, T.M., 1981, Ap. J. Lett., 250, L59.Google Scholar
Heckman, T.M. 1986, P.A.S.P., 98, 159.Google Scholar
Heckman, T.M., Armus, L., and Miley, G.K. 1986 (HAM), submitted to Astr. J. Google Scholar
Hu, E.M., Cowie, L.L., and Wang, Z. 1985, Ap. J. Suppl., 59. 447.Google Scholar
Keel, W.C. 1983a, Ap. J., 269, 466.Google Scholar
Keel, W.C. 1983b, Ap. J. Suppl.Google Scholar
Keel, W.C. 1985, in “Astrophysics of Active Galaxies and Quasi-Stellar Objects”, ed. Miller, J.S. (University Science Books: Mill Valley, CA), p. 1.Google Scholar
Keel, W.C., and Miller, J.S. 1983, Ap. J. Lett., 266, L89.CrossRefGoogle Scholar
Kent, S.M., and Sargent, W.L.W. 1979, Ap. J., 230, 667.Google Scholar
Koski, A.T., and Osterbrock, D.E. 1976, Ap. J. Lett., 203, L49.Google Scholar
Krolik, J.H., McKee, C.F., and Tarter, C.B. 1981, Ap. J., 249, 422.Google Scholar
Kronberg, P.P., Biermann, P., and Schwab, F.R. 1985, Ap. J., 291, 693.Google Scholar
Lake, G., and Norman, C., 1983, Ap. J., 270, 51.Google Scholar
Lawrence, A., Ward, M., Elvis, M., Fabbiano, G., Willner, S.P., Carleton, N.P., and Longmore, A. 1985, Ap. J., 291, 117.Google Scholar
Mathews, W.G., and Bregman, J.N. 1978, Ap. J., 224, 308.Google Scholar
McCarthy, P.J., Heckman, T.M., and van Breugel, W.J.M. 1986 (MHvB), submitted to Astr. J. Google Scholar
McCarthy, P.J., van Breugel, W.J.M., Heckman, T.M., Miley, G.K., and Baum, S.A. 1986, in preperation.Google Scholar
Nakai, N. 1984, , University of Tokyo.Google Scholar
Nulsen, P.E.J., Stewart, G.C., and Fabian, A.C. 1984, M.N.R.A.S., 208, 185.Google Scholar
O'Connell, R.W., and Dressel, L.L. 1978, Nature, 276, 374.Google Scholar
Osterbrock, D.E., and Mathews, W.G. 1986, Ann. Rev. Astr. Ap., 24, 171.Google Scholar
Pequignot, D. 1984, Astr. Ap., 131, 159.Google Scholar
Phillips, M.M. 1981, M.N.R.A.S., 197, 659.Google Scholar
Phillips, M.M., Jenkins, C.R., Dopita, M.A., Sadler, E.M., and Binette, L. 1986, Astr. J., 91, 1062.Google Scholar
Raymond, J.C. 1979, Ap. J. Suppl., 39, 1.Google Scholar
Rees, M.J. 1984, Ann. Rev. Astro. Ap., 22, 471.Google Scholar
Rose, J.A., and Tripicco, M.J. 1984, Ap. J., 285, 55.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., 238, 24.Google Scholar
Sarazin, C.L. 1986a, in “Proceedings of the Greenbank Workshop on Gaseous Halos Around Galaxies”, ed. Bregman, J. and Lockman, F. (NRAO: Charlottesville, VA), in press.Google Scholar
Sarazin, C.L. 1986b, Rev. Mod. Phys., 58, 1.Google Scholar
Scoville, N.Z., Soifer, B.T., Neugebauer, G., Young, J.S., Matthews, K., and Yerka, J. 1985, Ap. J., 289, 129.Google Scholar
Shull, J.M., and McKee, C.F., 1979, Ap. J., 227, 131.Google Scholar
Stasinska, G. 1984, Astr. Ap. Suppl., 55, 15.Google Scholar
Stauffer, J.R. 1982a, Ap. J., 262, 66.Google Scholar
Stauffer, J.R. 1982b, Ap. J. Suppl., 50, 517.Google Scholar
Terlevich, R., and Melnick, J. 1985, M.N.R.A.S., 213, 841.Google Scholar
Ulrich, M.-H. 1978, Ap. J., 219, 424.Google Scholar
Veilleux, S., and Osterbrock, D.E. 1986, preprint.Google Scholar
Watson, M.G., Stanger, V., and Griffiths, R.E. 1984, Ap. J., 286, 144.Google Scholar
Whittle, M. 1985, M.N.R.A.S., 213, 1.Google Scholar
Wilson, A.S., and Heckman, T.M. 1985, in “Astrophysics of Active Galaxies and Quasi-Stellar Objects”, ed. Miller, J.S. (University Science Books: Mill Valley, CA), p. 39.Google Scholar