Skip to main content
SpringerLink
Log in

Continuum radiation from active galactic nuclei

  • Published:
The Astronomy and Astrophysics Review Aims and scope

Summary

Active galactic nuclei (AGN) can be divided into two broad classes, where the emitted continuum power is dominated either by thermal emission (radio-quiet AGN), or by nonthermal emission (blazars). Emission in the 0.01–1 μm range is the primary contributor to the bolometric luminosity and is probably produced through thermal emission from an accretion disk, modified by electron scattering and general relativistic effects. The 1–1000 μm continuum, the second most important contributor to the power, is generally dominated by thermal emission from dust with a range of temperatures from ∼ 40 K to ∼ 1000–2000 K. The dust is probably reemitting 0.01–0.3 μm continuum emission, previously absorbed in an obscuring cone (or torus) or an extended disk. The 1–10 keV X-ray emission is rapidly variable and originates in a small region. This emission may be produced through Compton scattering by hot thermal electrons surrounding an accretion disk, although the observations are far from being definitive. The weak radio emission, which is due to the nonthermal synchrotron process, is usually elongated in the shape of jets and lobes (a core may be present too), and is morphologically distinct from the radio emission of starburst galaxies.

In the blazar class, the radio through ultraviolet emission is decidedly non-thermal, and apparently is produced through the synchrotron process in an inhomogeneous plasma. The plasma probably is moving outward at relativistic velocities within a jet in which the Lorentz factor of bulk motion (typically 2–6) increases outward. This is inferred from observations indicating that the opening angle becomes progressively larger from the radio to the optical to the X-ray emitting regions. Shocks propagating along the jet may be responsible for much of the flux variability. In sources where the X-ray continuum is not a continuation of the optical-ultraviolet synchrotron emission, some objects show variability consistent with Compton scattering by relativistic electron in a large region (in BL Lacertae), while other objects produce their X-ray emission in a compact region, possibly suggesting pair production.

When orientation effects are included, all AGN may be decomposed into a radio-quiet AGN, a blazar, or a combination of the two. Radio-quiet AGN appear to have an obscuring cone or torus containing the broad emission line clouds and an ionizing source. Most likely, the (non-relativistic) directional effects of this obscuring region give rise to the difference between Seyfert 1 and 2 galaxies or narrow and broad line radio galaxies. For different orientations of the nonthermal jet, relativistic Doppler boosting can produce BL Lacertae objects or FR I radio galaxies, or at higher jet luminosities, flat-spectrum high-polarization quasars or FR II radio galaxies.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Abramowicz, M.A., Nobili, L.: 1982,Nature 300, 506

    Google Scholar 

  • Agrawal, P.C., Singh, K.P., Riegler, G.R.: 1987,Monthly Notices Roy. Astron. Soc. 227, 525

    Google Scholar 

  • Aitken, D.K., Roche, P.F.: 1985,Monthly Notices Roy. Astron. Soc. 213, 777

    Google Scholar 

  • Aller, H.D., Adler, M.F., Latimer, G.E., Hodge, P.E.: 1985,Astrophys. J. Suppl. 59, 513

    Google Scholar 

  • Altschuler, D.R.: 1982,Astron. J. 87, 387

    Google Scholar 

  • Altschuler, D.R.: 1983,Astron. J. 88, 16

    Google Scholar 

  • Altschuler, D.R.: 1989,Fund. of Cosmic Physics 14, 37

    Google Scholar 

  • Antonucci, R.R.J.: 1984,Astrophys. J. 278, 299

    Google Scholar 

  • Antonucci, R.R.J., Barvainis, R.: 1988,Astrophys. J. Letters 322, L13

    Google Scholar 

  • Antonucci, R.R.J., Kinney, A.L., Ford, H.C.: 1989,Astrophys. J. 342, 64

    Google Scholar 

  • Antonucci, R.R.J., Miller, J.S.: 1985,Astrophys. J. 297, 621

    Google Scholar 

  • Antonucci, R.R.J., Hickson, P., Miller, J.S., Olszewski, E.W.: 1987,Astron. J. 93, 785

    Google Scholar 

  • Arnaud, K.A. et al.: 1985,Monthly Notices Roy. Astron. Soc. 217, 105

    Google Scholar 

  • Axon, D.J., Unger, S.W., Pedlar, A., Meurs, E.J.A., Whittle, D.M., Ward, M.J.: 1989,Nature 341, 631

    Google Scholar 

  • Babadyhanzants, M.K., Belokon', E.T.: 1984,Astrophysics 21, 461

    Google Scholar 

  • Babadyhanzants, M.K.: 1986,Astrophysics 23, 639

    Google Scholar 

  • Ballard, K.R. et al.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H.: Springer, Berlin Heidelberg New York, p. 181

    Google Scholar 

  • Ballard, K.R., Mead, A.R.G., Brand, P.W.J.L., Hough, J.H.: 1990,Monthly Notices Roy. Astron. Soc. 243, 640

    Google Scholar 

  • Balonek, T.J.: 1982, Ph. D. Thesis, University of Massachusetts

  • Balzano, V.A., Weedman, D.W.: 1981,Astrophys. J. 243, 756

    Google Scholar 

  • Barbieri, C., Cappellaro, E., Romano, G., Turatto, M., Szuszkiewicz, E.: 1988,Astron. Astrophys. Suppl. 76, 477

    Google Scholar 

  • Barr, P., Giommi, P., Pollock, A., Tagliaferri, G., Maccagni, D., Garilli, B. 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H.: Springer, Berlin Heidelberg New York, p. 290

    Google Scholar 

  • Barstow, M.A., Stanger, V.J.: 1988,Monthly Notices Roy. Astron. Soc. 230, 207

    Google Scholar 

  • Barthel, P.D.: 1989,Astrophys. J. 336, 606

    Google Scholar 

  • Barvainis, R.: 1987,Astrophys. J. 320, 537

    Google Scholar 

  • Barvainis, R., Alloin, D., Antonucci, R.: 1989,Astrophys. J. Letters 337, L69

    Google Scholar 

  • Barvainis, R., Antonucci, R.: 1989,Astrophys. J. Suppl. 70, 173

    Google Scholar 

  • Bassini, L., Dean, A.J., Sembay, S.: 1983,Astron. Astrophys. 125, 52

    Google Scholar 

  • Bechtold, J., Czerny, B., Elvis, M., Fabbiano, G., Green, R.F.: 1987,Astrophys. J. 314, 699

    Google Scholar 

  • Begelman, M.C.: 1985, inAstrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J.S., Mill Valley: University Science Books, p. 411

    Google Scholar 

  • Begelman, M.C., Blandford, R.D., Rees, M.J.: 1984,Rev. Mod. Phys. 56, 255

    Google Scholar 

  • Beichman, C.A., Neugebauer, G., Soifer, B.T., Wootten, H.A., Roellig, T., Harvey, P.M.: 1981 a,Nature 293, 711

    Google Scholar 

  • Beichman, C.A., Provdo, S.H., Neugebauer, G., Soifer, B.T., Matthews, K., Wootten, H.A.: 1981 b,Astrophys. J. 247, 780

    Google Scholar 

  • Bell, A.R.: 1978,Monthly Notices Roy. Astron. Soc. 182, 147

    Google Scholar 

  • Bezler, M., Gruber, D.E., Rothschild, R.E.: 1988,Astrophys. J. 334, 995

    Google Scholar 

  • Biretta, J.A., Moore, R.L., Cohen, M.H.: 1986,Astrophys. J. 308, 93

    Google Scholar 

  • Blandford, R.D.: 1987, inSuperluminal Radio Sources, eds. Zensus, J.A., Pearson, T.J., Cambridge Press, Cambridge, p. 40

    Google Scholar 

  • Blandford, R.D., Eichler, D.: 1987,Physics Reports,154, 1

    Google Scholar 

  • Blandford, R.D., Konigl, A.: 1979,Astrophys. J. 232, 34

    Google Scholar 

  • Blandford, R.D., McKee, C.F., Rees, M.J.: 1977,Nature 267, 563

    Google Scholar 

  • Blandford, R.D., Ostriker, J.P.: 1978,Astrophys. J. (letters) 221, L29

    Google Scholar 

  • Botti, L.C.L., Abraham, Z.: 1987,Rev. Mex. Astron. Astrofis. 14, 97

    Google Scholar 

  • Branduardi-Raymont, G., Mittaz, J.P.D.: 1988,Adv. Space Res. 8, 61

    Google Scholar 

  • Bregman, J.N.: 1985,Astrophys. J. 288, 32

    Google Scholar 

  • Bregman, J.N., Boisseau, J.R.: 1989,Astrophys. J. 247, 118

    Google Scholar 

  • Bregman, J.N., Hufnagel, B.R.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 159

    Google Scholar 

  • Bregman, J.N. et al.: 1981,Nature 293, 714

    Google Scholar 

  • Bregman, J.N. et al.: 1984,Astrophys. J. 276, 454

    Google Scholar 

  • Bregman, J.N. et al.: 1986,Astrophys. J. 301, 708

    Google Scholar 

  • Bregman, J.N. et al.: 1988,Astrophys. J. 331, 746

    Google Scholar 

  • Bregman, J.N. et al.: 1990,Astrophys. J. 352, 574

    Google Scholar 

  • Bregman, J.N., Maraschi, L., Urry, C.M.: 1987, inScientific Accomplishments of the IUE, ed. Kondo, Y., Reidel, Dordrecht, p. 685

    Google Scholar 

  • Bridle, A.H.: 1987, inActive Galactic Nuclei, eds. Miller, H.R., Wiita, P.J., Springer, Berlin Heidelberg New York, p. 329

    Google Scholar 

  • Bridle, A.H., Perley, R.A.: 1984,Ann. Rev. Astron. Astrophys. 22, 319

    Google Scholar 

  • Brindle, C. et al.: 1985,Monthly Notices Roy. Astron. Soc. 214, 619

    Google Scholar 

  • Brock, D., Joy, M., Lester, D.F., Harvey, P.M., Ellis, H.B.: 1988,Astrophys. J. 329, 208

    Google Scholar 

  • Brown, L.M.J. et al.: 1989a,Astrophys. J. 340, 129

    Google Scholar 

  • Brown, L.M.J., Robson, E.I., Gear, W.K., Smith, M.G.: 1989b,Astrophys. J. 340, 162

    Google Scholar 

  • Browne, I.W.A.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 401

    Google Scholar 

  • Brunner, H., Worrall, D.M., Wilkes, B.J., Elvis, M.: 1989, Proceedings of the 23d ESLAB Symposium, (ESA SP. 296), p. 905

  • Burstein, D., Heiles, C: 1982,Astron. J. 87, 1165

    Google Scholar 

  • Carini, M.T.: 1990, Ph. D. Thesis, Georgia State University

  • Carleton, N.P., Elvis, M., Fabbiano, G., Willner, S.P., Lawrence, A., Ward, M.: 1987,Astrophys. J. 18, 595

    Google Scholar 

  • Cawthorne, T.V., Wardle, J.F.C.: 1988,Astrophys. J. 332, 696

    Google Scholar 

  • Celotti, A., Maraschi, L., Treves, A.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 332

    Google Scholar 

  • Cheng, F.H., Shields, G.A., Lin, D.N.C., Pringle, J.: 1988,Astrophys. J. 328, 223

    Google Scholar 

  • Chini, R., Biermann, P.L., Kreysa, E., Kuhr, H., Mezger, P.G., Schmidt, J., Witzel, A., Zensus, J.A.: 1987,Astron. Astrophys. 181, 237

    Google Scholar 

  • Chini, R., Krerysa, E., Salter, C.J.: 1987,Astron. Astrophys. 182, L63

    Google Scholar 

  • Chini, R., Steppe, H., Kreysa, E., Krichbaum, T., Quirrenbach, A., Schalinski, C., Witzel, A.: 1988,Astron. Astrophys. 192, L1

    Google Scholar 

  • Chini, R., Kreysa, E., Biermann, P.L.: 1989,Astron. Astrophys. 219, 87

    Google Scholar 

  • Clavel et al.: 1989,Astrophys. J. 337, 236

    Google Scholar 

  • Clegg, P.E. et al.: 1983,Astrophys. J. 273, 58

    Google Scholar 

  • Clement, R., Sembay, S., Hanson, C.G., Coe, M.J.: 1988,Monthly Notices Roy. Astron. Soc. 230, 117

    Google Scholar 

  • Cohen, M.H.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 13

    Google Scholar 

  • Coleman, H.H., Shields, G.A.: 1990,Astrophys. J. (in press)

  • Corso, G.J. et al.: 1988,Pub. Astron. Soc. Pacific 100, 70

    Google Scholar 

  • Courvoisier, T.J.-L. et al.: 1987,Astron. Astrophys. 176, 197

    Google Scholar 

  • Courvoisier, T.J.-L. et al.: 1988,Nature 335, 330

    Google Scholar 

  • Courvoisier, T.J.-L. et al.: 1990,Astron. Astrophys. (in press)

  • Czerny, B., Elvis, M.: 1987,Astrophys. J. 321, 305

    Google Scholar 

  • Done, C., Ward, M.J., Fabian, A.C., Kunieda, H., Tsuruta, S., Lawrence, A., Smith, M.G., Wamsteker, W.: 1990,Monthly Notices Roy. Astron. Soc. 243, 713

    Google Scholar 

  • Doxsey, R. et al.: 1983,Astrophys. J. Letters 264, L43

    Google Scholar 

  • Draine, B.T., Anderson, N.: 1985,Astrophys. J. 292, 494

    Google Scholar 

  • Eales, S.A., Arnaud, K.A.: 1988,Astrophys. J. 324, 193

    Google Scholar 

  • Edelson, R.A., Gear, W.K.P., Malkan, M.A., Robson, E.I.: 1988,Nature 336, 749

    Google Scholar 

  • Edelson, R.A., Malkan, M.A.: 1986,Astrophys. J. 308, 59

    Google Scholar 

  • Edelson, R.A., Malkan, M.A.: 1987,Astrophys. J. 323, 516

    Google Scholar 

  • Edelson, R.A., Malkan, M.A., Rieke, G.H.: 1987,Astrophys. J. 321, 233

    Google Scholar 

  • Elias, J.H. et al.: 1978,Astrophys. J. 220, 25

    Google Scholar 

  • Elliot, J.L., Shaprio, S.L.: 1974,Astrophys. J. Letters 192, L3

    Google Scholar 

  • Elvis, M.: 1989,Comments in Astrophysics 14, 177

    Google Scholar 

  • Elvis, M., Green, R.F., Bechtold, J., Schmidt, M., Neugebauer, G., Soifer, B.T., Matthews, K., Fabbiano, G.: 1986,Astrophys. J. 310, 291

    Google Scholar 

  • Elvis, M., Wilkes, B.J., McDowell, J.C.: 1990, inExtreme Ultraviolet Astronomy, ed. Malina, R.F., Bowyer, S, Pergamon, New York (in press)

    Google Scholar 

  • Elvis, M., Wilkes, B.J., Tananbaum, H.: 1985,Astrophys. J. 292, 357

    Google Scholar 

  • Engargiola, G., Harper, D.A., Elvis, M., Willner, S.P.: 1988,Astrophys. J. Letters 322, L19

    Google Scholar 

  • Epstein, E.E., Fogarty, W.G., Mottmann, J., Schneider, E.: 1982,Astron. J. 87, 449

    Google Scholar 

  • Fabian, A.C.: 1988, inSupermassive Black Holes, ed. Kafatos, M., Cambridge Univ. Press, Cambridge, p. 234

    Google Scholar 

  • Fiedler, R.L. et al.: 1987,Astrophys. J. Suppl.,65, 319

    Google Scholar 

  • Feigelson, E.D. et al.: 1986,Astrophys. J. 302, 337

    Google Scholar 

  • Flett, A.M., Henderson, C.: 1981,Monthly Notices Roy. Astron. Soc. 194, 961

    Google Scholar 

  • Fritz, K.D.: 1989,Astron. Astrophys. 214, 14

    Google Scholar 

  • Gabuzda, D.C., Cawthorne, T.V., Roberts, D.H., Wardle, J.F.C. 1989,Astrophys. J. 347, 701

    Google Scholar 

  • Gabuzda, D.C., Wardle, J.F.C., Roberts, D.H.: 1989,Astrophys. J. Letters 336, 59

    Google Scholar 

  • Garilli, B., Maccagni, D.: 1990,Astron. Astrophys. 229, 88

    Google Scholar 

  • Garrinton, S.T., Leahy, J.P., Conway, R.G., Laing, R.A.: 1988,Nature 331, 147

    Google Scholar 

  • Gear, W.K. et al.: 1985,Astrophys. J. 291, 511

    Google Scholar 

  • Gear, W.K., Brown, L.M.J., Robson, E.I., Ade, P.A.R., Griffin, M.J., Smith, M.G., Nolt, I.G., Radostitz, J.V., Veeder, G., Lebofsky, L.: 1986,Astrophys. J. 304, 295

    Google Scholar 

  • George, I.M., Warwick, R.S., Bromage, G.E.: 1988,Monthly Notices Roy. Astron. Soc. 232, 793

    Google Scholar 

  • Ghisellini, G., Maraschi, L., Tanzi, E., Treves, A.: 1986,Astrophys. J. 310, 317

    Google Scholar 

  • Ghisellini, G., Maraschi, L., Tanzi, E., Treves, A.: 1985,Astron. Astrophys. 146, 204

    Google Scholar 

  • Ghisellini, G., Maraschi, L.: 1989,Astrophys. J. 340, 181

    Google Scholar 

  • Giommi, P. et al.: 1986,Astrophys. J. 303, 596

    Google Scholar 

  • Giommi, P. et al.: 1987,Astrophys. J. 322, 662

    Google Scholar 

  • Giommi, P., Barr, P., Garilli, B., Maccagni, D., Pollock, A.M.T.: 1990,Astrophys. J. (in press)

  • Glassgold, A.E. et al.: 1983,Astrophys. J. 274, 101

    Google Scholar 

  • Goodrich, R.W.: 1989,Astrophys. J. 340, 190

    Google Scholar 

  • Goodrich, R.W., Miller, J.S.: 1988,Astrophys. J. 331, 332

    Google Scholar 

  • Griffiths, R.E., Wilson, A.S., Ward, M.J., Tapia, S., Ulvestad, J.: 1989,Monthly Notices Roy. Astron. Soc. 240, 33

    Google Scholar 

  • Hagen-Thorn, V.A., Denisenko, N.S., Maksimova, T.M., Marchenko, S.G., Mikolajchuk, O.V.: 1987,Tr. Astron. Obs., Tom. Leningrad41, 96

    Google Scholar 

  • Halpern, J.: 1982,Ph. D. Thesis, Harvard University

  • Haniff, C.A., Wilson, A.S., Ward, M.J.: 1988,Astrophys. J. 334, 104

    Google Scholar 

  • Heavens, A.F., Meisenheimer, K.: 1987,Monthly Notices Roy. Astron. Soc. 225, 335

    Google Scholar 

  • Heeschen, D.S., Krichbaum, T., Schalinski, C.J., Witzel, A.: 1987,Astron. J. 94, 1493

    Google Scholar 

  • Hildebrand, R.H., Whitcomb, S.E., Winston, R., Stiening, R.F., Harper, D.A., Moseley, S.H.: 1977,Astrophys. J. 216, 698

    Google Scholar 

  • Hughes, P.A., Aller, H.D., Aller, M.F.: 1989 a,Astrophys. J. 341, 54

    Google Scholar 

  • Hughes, P.A., Aller, H.D., Aller, M.F.: 1989 b,Astrophys. J. 341, 68

    Google Scholar 

  • Hutchings, J.B., Janson, T., Neff, S.G.: 1989,Astrophys. J. 342, 660

    Google Scholar 

  • Hutter, D.J., Mufson, S.L.: 1986,Astrophys. J. 301, 50

    Google Scholar 

  • Hyland, H.R., Allen, D.A.: 1982,Monthly Notices Roy. Astron. Soc. 199, 943

    Google Scholar 

  • Impey, C.D.: 1987 inSuperluminal Radio Sources, eds. Zensus, J.A., Peason, T.J. (CUP, Cambridge), p. 233

    Google Scholar 

  • Impey, C.D., Neugebauer, G.: 1988,Astron. J. 95, 307

    Google Scholar 

  • Impey, C.D., Tapia, S.: 1990,Astrophys. J. (in press)

  • Johnston, K.J. et al.: 1984,Astrophys. J. Letters 277, L31

    Google Scholar 

  • Jones, B., Worrall, D.M., Rodriguez-Espinoza, J.M., Stein, W.A., Gillett, F.C.: 1984,Pub. Astron. Soc. Pacific 96, 692

    Google Scholar 

  • Jones, T.W., O'Dell, S.L., Stein, W.A.: 1974,Astrophys. J. 188, 353

    Google Scholar 

  • Jones, T.W., Stein, W.A.: 1987,Astrophys. J. Letters 320, Ll

    Google Scholar 

  • Jones, T.W., Stein, W.A.: 1990,Astrophys. J. 349, 443

    Google Scholar 

  • Kaastra, J.S., Barr, P.: 1989,Astron. Astrophys. 226, 59

    Google Scholar 

  • Kawaii, N. et al.: 1990, in the23rd ESLAB Symposium, Two Topics in X-Ray Astronomy (in press)

  • Kellermann, K.I., Pauliny-Toth, I.I.K.: 1981,Ann. Rev. Astron. Astrophys. 19, 373

    Google Scholar 

  • Kellermann, K.I., Sramek, R., Shaffer, D., Green, R.F., Schmidt, M.: 1989,Astron. J. 98, 1195

    Google Scholar 

  • Kidger, M.K.: 1988,Pub. Astron. Soc. Pacific 100, 1248

    Google Scholar 

  • Kikuchi, S.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin, p. 131

    Google Scholar 

  • Kikuchi, S., Inoue, M., Mikami, Y., Tabara, H., Kato, T.: 1988,Astron. Astrophys. 190, L8

    Google Scholar 

  • Kolykhalov, P.I., Sunyaev, R.A.: 1984,Adv. Space Res. 3, 249

    Google Scholar 

  • Konigl, A.: 1981,Astrophys. J. 243, 700

    Google Scholar 

  • Konigl, A.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin, p. 321

    Google Scholar 

  • Krolik, J.H., Begelman, M.C.: 1986,Astrophys. J. Letters 308, L55

    Google Scholar 

  • Krolik, J.H., Begelman, M.C.: 1988,Astrophys. J. 329, 702

    Google Scholar 

  • Krugel, E., Chini, R., Kreysa, E., Sherwood, W.A.: 1988,Astron. Astrophys. 193, L16

    Google Scholar 

  • Krugel, E., Kreysa, E., Gemund, H.-P.: 1989,Astron. Astrophys. 216, L5

    Google Scholar 

  • Kruper, J.S., Urry, C.M., Canizares, C.R.: 1990,Astrophys. J. Suppl. (in press)

  • Kulshretha, A., Deshpande, M.R., Hoshi, U.C.: 1987,Astron. Astrophys. Suppl. 71, 565

    Google Scholar 

  • Laing, R.A.: 1988,Nature 331, 149

    Google Scholar 

  • Landau, R. et al.: 1986,Astrophys. J. 308, 78

    Google Scholar 

  • Laor, A., Netzer, H.: 1989,Monthly Notices Roy. Astron. Soc. 238, 897

    Google Scholar 

  • Laor, A., Netzer, H., Piran, T.: 1990,Monthly Notices Roy. Astron. Soc. 242, 560

    Google Scholar 

  • Lawrence, A.: 1987,Pub. Astron. Soc. Pacific 99, 309

    Google Scholar 

  • Lawrence, A., Pounds, K.A., Watson, M.G., Elvis, M.S.: 1987,Nature 325, 692

    Google Scholar 

  • Lawrence, A.: 1988, inComets to Cosmology, Ed. Lawrence, A., Springer, Berlin, p. 217

    Google Scholar 

  • Lawrence, A., Rowan-Robinson, M., Leech, K., Jones, D.H.P., Wall, J.V.: 1989,Monthly Notices Roy. Astron. Soc. 240, 329–348

    Google Scholar 

  • Lebofsky, M.J., Rieke, G.H.: 1980,Nature 284, 410

    Google Scholar 

  • Lind, K.R., Blandford, R.D.: 1985,Astrophys. J. 295, 358

    Google Scholar 

  • Lloyd, C.: 1984,Monthly Notices Roy. Astron. Soc. 209, 697

    Google Scholar 

  • Lorenzetti, D., Massaro, E., Perola, G.C., Spinoglio, L.: 1987,Mem. Soc. Astron. Ital. 58, 279

    Google Scholar 

  • MacAlpine, G.M.: 1985, inAstrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J.S., University Science Books, Mill Valley, p. 259

    Google Scholar 

  • MacAlpine, G.M., Davidson, K., Gull, T.R., Wu, C.-C.: 1985,Astrophys. J. 294, 147

    Google Scholar 

  • Maccacaro, T., Gioia, I.M., Wolter, A., Zamorani, G., Stocke, J.T.: 1988,Astrophys. J. 326, 680

    Google Scholar 

  • Madejski, G.M., Schwartz, D.A.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H. Springer, Berlin, p. 267

    Google Scholar 

  • Makino, F.: 1990, in the23rd ESLAB Symposium: Two Topics in X-Ray Astronomy (in press)

  • Makino, F. et al.: 1987,Astrophys. J. 313, 662

    Google Scholar 

  • Makino, F. et al.: 1989,Astrophys. J. Letters 347, L9

    Google Scholar 

  • Malkan, M.A.: 1983,Astrophys. J. 268, 582

    Google Scholar 

  • Malkan, M.A.: 1988,Adv. Space Res. 8, 49

    Google Scholar 

  • Malkan, M.: 1989, inDynamics of Astrophysical Disks, ed. Sellwood, J., Cambridge Univ. Press, Cambridge (in press)

    Google Scholar 

  • Malkan, M.A., Sargent, W.L.W.: 1982,Astrophys. J. 254, 22

    Google Scholar 

  • Maraschi, L.: 1988,Adv. Sp. Res., Vol. 8, No. 2–3, 85–94

    Google Scholar 

  • Maraschi, L., Ghisellini, G., Tanzi, E., Treves, A.: 1986,Astrophys. J. 310, 325

    Google Scholar 

  • Maraschi, L., Molendi, S.: 1990 (preprint)

  • Marscher, A.P.: 1980,Astron. J. 235, 386

    Google Scholar 

  • Marscher, A.P., Gear, W.K.: 1985,Astrophys. J. 298, 114

    Google Scholar 

  • Martin, P.G., Thompson, I.B., Maza, J., Angel, J.R.P.: 1983,Astrophys. J. 266, 470

    Google Scholar 

  • McAlary, C.W., Rieke, G.H.: 1988,Astrophys. J. 333, 1

    Google Scholar 

  • McDowell, J.C., Elvis, M., Wilkes, B.J., Willner, S.P., Oey, M.S., Polomski, E., Bechtold, J., Green, R.F.: 1989,Astrophys. J. 345 Letters, L13

    Google Scholar 

  • McHardy, I.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin, p. 189

    Google Scholar 

  • McHardy, I., Czerny, B.: 1987,Nature 325, 696

    Google Scholar 

  • Mead, A.R.G., Brand, P.W.J.L., Hough, J.H., Bailey, J.A.: 1988,Monthly Notices Roy. Astron. Soc. 233, 503

    Google Scholar 

  • Mead, A.R.G., Ballard, K.R., Brand, P.W.J.L., Hough, J.H., Brindle, C., Bailey, J.A.: 1990,Astron. Astrophys. Suppl. 83, 183

  • Melia, F., Konigl, A.: 1989,Astrophys. J. 340, 162

    Google Scholar 

  • Meurs, E.J.A., Wilson, A.S.: 1984,Astron. Astrophys. 136, 206

    Google Scholar 

  • Miley, G.K.: 1980,Ann. Rev. Astron. Astrophys. 18, 165

    Google Scholar 

  • Miley, G.K., Neugebauer, G., Clegg, P.E., Harris, S., Rowan-Robinson, M., Soifer, B.T., Young, E.: 1984,Astrophys. J. Letters 278, L79

    Google Scholar 

  • Miley, G.K., Neugebauer, G., Soifer, B.T.: 1985,Astrophys. J. Letters 293, L11

    Google Scholar 

  • Miller, H.R., Carini, M.T.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin, p. 143

    Google Scholar 

  • Miller, J.S.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin, p. 395

    Google Scholar 

  • Miller, J.S., Antonucci, R.R.J.: 1983,Astrophys. J. Letters 271, L7

    Google Scholar 

  • Mitra, A.: 1990,Astrophys. J. 348, 221

    Google Scholar 

  • Moles, M., Garcia-Pelazo, J.M., Masegosa, J., Garrido, R.: 1986,Astron. J. 92, 1030

    Google Scholar 

  • Morini, M. et al.: 1986,Astrophys. J. Letters 306, L71

    Google Scholar 

  • Moore, R.L. et al.: 1982,Astrophys. J. 260, 415

    Google Scholar 

  • Moore, R.L., Schmidt, G.D., West, S.C.: 1987,Astrophys. J. 314, 176

    Google Scholar 

  • Moore, R.L., Stockman, H.S.: 1981,Astrophys. J. 243, 60

    Google Scholar 

  • Moore, R.L., Stockman, H.S.: 1984,Astrophys. J. 279, 465

    Google Scholar 

  • Mufson, S.L., Hutter, D.J., Kondo, Y.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin, p. 341

    Google Scholar 

  • Mushotzky, R.F.: 1982,Astrophys. J. 256, 92

    Google Scholar 

  • Mushotzky, R.F.: 1984,Adv. Space Res. 3, 157

    Google Scholar 

  • Mushotzky, R.F.: 1987 inActive Galactic Nuclei, eds. Miller, H.R., Wiita, P.J., Springer, Berlin, p. 239

    Google Scholar 

  • Mutel, R.L., Phillips, R.B., Su, B., Bucciferro, R.R.: 1990,Astrophys. J. 352, 81

    Google Scholar 

  • Nandra et al.: 1989,Monthly Notices Roy. Astron. Soc. 236, 39P

  • Netzer, H.: 1985,Monthly Notices Roy. Astron. Soc. 216, 63

    Google Scholar 

  • Netzer, H.: 1987,Monthly Notices Roy. Astron. Soc. 225, 55

    Google Scholar 

  • Neugebauer, G., Becklin, E.E., Oke, J.B., Searle, L.: 1976,Astrophys. J. 205, 29

    Google Scholar 

  • Neugebauer, G., Oke, J.B., Becklin, E.E., Matthews, K.: 1979,Astrophys. J. 230, 79

    Google Scholar 

  • Neugebauer, G. et al.: 1984,Astrophys. J. Letters 278, L83

    Google Scholar 

  • Neugebauer, G., Soifer, B.T., Matthews, K., Elias, J.H.: 1989,Astron. J. 97, 957

    Google Scholar 

  • Norris, R.P., Allen, D.A., Roche, P.F.: 1988,Monthly Notices Roy. Astron. Soc. 234, 773–782

    Google Scholar 

  • Norris, R.P., Kesteven, M.J., Allen, D.A., Troupe, E.: 1988,Monthly Notices Roy. Astron. Soc. 234, 51P

    Google Scholar 

  • O'Brien, P.T., Gondhalekar, P.M., Wilson, R.: 1988 a,Monthly Notices Roy. Astron. Soc. 233, 801

    Google Scholar 

  • O'Brien, P.T., Gondhalekar, P.M., Wilson, R.: 1988 b,Monthly Notices Roy. Astron. Soc. 233, 845

    Google Scholar 

  • O'Dell, S.L. et al.: 1988b,Astrophys. J. 326, 668

    Google Scholar 

  • Ohashi, T.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin, p. 296

    Google Scholar 

  • Ohashi, T., Makishima, K., Inoue, H., Koyama, K., Makino, F., Turner, M., and Warwick, R.: 1989,Pub. Astron. Soc. Japan 41, 709

    Google Scholar 

  • Orr, M.J.L., Browne, I.W.A.: 1982,Monthly Notices Roy. Astron. Soc. 200, 1067

    Google Scholar 

  • Osterbrock, D.E., Mathews, W.G.: 1986,Ann. Rev. Astron. Astrophys. 24, 171

    Google Scholar 

  • Owen, F.N.: 1986, inIAU Symposium 119, Quasars, ed. Swarup, G., Kapahi, V.K., Reidel, Dordrecht, p. 173

    Google Scholar 

  • Pacholczyck, A.G., Wisniewski, W.Z.: 1967,Astrophys. J. 147, 394

    Google Scholar 

  • Padovani, P., Urry, C.M.: 1990,Astrophys. J. (in press)

  • Peacock, J.A.: 1987, inSuperluminal Radio Sources, eds. Zensus, J.A., Pearson, T.J., Cambridge University Press, Cambridge, p. 12

    Google Scholar 

  • Penston, M.V., Penston, M.J., Selmes, R.A., Becklin, E.E., Neugebauer, G.: 1974,Monthly Notices Roy. Astron. Soc. 169, 357

    Google Scholar 

  • Petre, R., Mushotzky, R., Krolik, J., Holt, S.S.: 1984,Astrophys. J. 280, 499

    Google Scholar 

  • Perez, E., Penston, M.V., Moles, M.: 1989,Monthly Notices Roy. Astron. Soc. 239, 55

    Google Scholar 

  • Phomphrey, R.B.: 1976,Astron. J. 81, 489

    Google Scholar 

  • Pica, A.J., Smith, A.G., Pollock, J.T.: 1980,Astrophys. J. 236, 84

    Google Scholar 

  • Pica, A.J. et al.: 1988,Astrophys. J. 96, 1215

    Google Scholar 

  • Pogge, R.W.: 1988,Astrophys. J. 328, 519

    Google Scholar 

  • Pollock, A.M.T., Brand, P.W.J.L., Bregman, J.N., Robson, E.I.: 1985,Sp. Sci. Rev. 40, 607

    Google Scholar 

  • Pounds, K.: 1985, inProc. Japan/US Symposium on Galactic and Extragalactic X-Ray Sources, eds. Tanaka, Y., Lewin, W., ISAS, Tokyo, p. 261

    Google Scholar 

  • Pounds, K.A.: 1989, inProc. of the 23d ESLAB Symposium on X-Ray Astronomy ESA SP-296, p. 753

  • Pounds, K.A., McHardy, I.M.: 1988, inPhysics of Neutron Stars and Black Holes, ed. Tanaka, Y., Univ. Acad. Press, Tokyo, p. 285

    Google Scholar 

  • Pounds, K.A., Stanger, V.J., Turner, T.J., King, A.R., Czerny, B.: 1986,Monthly Notices Roy. Astron. Soc. 224, 443

    Google Scholar 

  • Pounds, K.A., Turner, T.J., Warwick, R.S.: 1986,Monthly Notices Roy. Astron. Soc. 221, 7P

    Google Scholar 

  • Prestage, R.M., Peacock, J.A.: 1988,Monthly Notices Roy. Astron. Soc. 230, 131

    Google Scholar 

  • Pustil'nik, S.A., Aliakberov, K.D.: 1987,Astrofiz. Issled. Izv. Spets. Astrofiz. Obs. 25, 68

    Google Scholar 

  • Rees, M.J.: 1984,Ann. Rev. Astron. Astrophys. 22, 471

    Google Scholar 

  • Rees, M.J., Silk, J.I., Werner, M.W., Wickramsinghe, M.C.: 1969,Nature 223, 788

    Google Scholar 

  • Reichert, G., Mushotzky, R., Petre, R., Holt, S.S.: 1985,Astrophys. J. 280, 499

    Google Scholar 

  • Reynolds, S.P.: 1982,Astrophys. J. 13

  • Rieke, G.H.: 1978,Astrophys. J. 226, 550

    Google Scholar 

  • Rieke, G.H.: 1985, inAstrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J.S., University Science Books, Mill Valley, p. 236

    Google Scholar 

  • Rieke, G.H.: 1988,Astrophys. J. Letters 331, L5

    Google Scholar 

  • Rieke, G.H., Cutri, R.M., Black, J.H., Kailey, W.F., McAlary, C.W., Lebofsky, M.J., Elston, R.: 1985,Astrophys. J. 290, 116

    Google Scholar 

  • Rieke, G.H., Grasdalen, T.L., Kinman, T.D., Hintzen, P., Wills, B.J., Wills, D.: 1976,Nature 260, 754

    Google Scholar 

  • Rieke, G.H., Lebofsky, M.J., Kinman, T.D.: 1979,Astrophys. J. Letters 232, L151

    Google Scholar 

  • Rieke, G.H., Lebofsky, M.J., Thompson, R.I., Low, F.J., Tokunaga, A.T.: 1980,Astrophys. J. 238, 24

    Google Scholar 

  • Rieke, G.H., Lebofsky, M.J., Wisniewski, W.Z.: 1982,Astrophys. J. 263, 73

    Google Scholar 

  • Roberts, D.H., Gabuzda, D.C., Wardle, J.F.C.: 1987,Astrophys. J. 323, 536

    Google Scholar 

  • Robson, E.I., Gear, W.K., Clegg, P.E., Ade, P.A.R., Smith, M.G., Griffin, M.J., Nolt, I.G., Radostitz, J.V., Howard, R.J.: 1983,Nature 305, 194

    Google Scholar 

  • Robson, E.I., Gear, W.K., Brown, L.M.J., Courvoisier, T.J.-L., Smith, M.G., Griffin, M.J., Blecha, A.: 1986,Nature 323, 134

    Google Scholar 

  • Roche, P.F., Aitken, D.K., Phillips, M.M., Whitmore, B.: 1984,Monthly Notices Roy. Astron. Soc. 207, 35

    Google Scholar 

  • Rothschild, R.E., Mushotzky, R.F., Baity, W.A., Gruber, D.E., Matteson, J.L., Primini, F.A.: 1983,Astrophys. J. 269, 423

    Google Scholar 

  • Rusk, R., Seaquist, E.R.: 1985,Astron. J. 90, 30

    Google Scholar 

  • Salonen, E. et al.: 1987,Astron. Astrophys. Suppl.70, 409

    Google Scholar 

  • Sanders, D.B., Phinney, E.S., Neugebauer, G., Soifer, B.T., Matthews, K.: 1989,Astrophys. J. 347, 29

    Google Scholar 

  • Sanders, D.B., Soifer, B.T., Elias, J.H., Madore, B.F., Matthews, K., Neugebauer, G., Scoville, N.Z.: 1988 a,Astrophys. J. 325, 74

    Google Scholar 

  • Sanders, D.B., Soifer, B.T., Elias, J.H., Neugebauer, G., Matthews, K.: 1988b,Astrophys. J. 328, L35

    Google Scholar 

  • Scheuer, P.A.G., Readhead, A.C.S.: 1797,Nature 277, 182

    Google Scholar 

  • Schwartz, D.A., Madejski, G.M.: 1987, inVariability of Galactic and Extragalactic X-Ray Sources, ed. Treves A., Associazione per l'Avazamento dell'Astronomia, Milano, p. 65

    Google Scholar 

  • Shakura, N.I., Sunyaev, R.A.: 1973,Astron. Astrophys. 24, 337

    Google Scholar 

  • Shields, G.A.: 1978,Nature 272, 706

    Google Scholar 

  • Shields, G.A., Filippenko, A.V.: 1988,Astrophys. J. Letters 332, L55

    Google Scholar 

  • Sillanpaa, A., Haarala, S., Korhonen, T.: 1988,Astron. Astrophys. Suppl. 72, 347

    Google Scholar 

  • Simons, D.A., Tokunaga, A.T., Rudy, R.J., Stein, W.A.: 1988,Astron. J. 96, 481

    Google Scholar 

  • Singh, K.P., Garmire, G.P., Nousek, J.: 1985,Astrophys. J. 297, 633

    Google Scholar 

  • Sitko, M.L., Schmidt, G.D., Stein, W.A.: 1985,Astrophys. J. Suppl. 59, 323

    Google Scholar 

  • Smith, C.H., Aitken, D.K., Roche, P.F.: 1989,Monthly Notices Roy. Astron. Soc. 241, 425

    Google Scholar 

  • Smith, E.P., Heckman, T.M.: 1990,Astrophys. J. 348, 38

    Google Scholar 

  • Smith, P.S., Balonek, T.J., Heckert, P.A., Elston, R.: 1986,Astrophys. J. 305, 484

    Google Scholar 

  • Smith, P.S., Balonek, T.J., Heckert, P.A., Elston, R.: 1987,Astrophys. J. Suppl. 64, 459

    Google Scholar 

  • Smith, P.S., Elston, R., Berriman, G., Allen, R.G., Balonek, T.J.: 1988,Astrophys. J. Letters 326, L39

    Google Scholar 

  • Soifer, B.T. et al.: 1984,Astrophys. J. 283, L1

    Google Scholar 

  • Soifer, B.T., Houck, J.R., Neugebauer, G.: 1987,Ann. Rev. Astron. Astrophys. 25, 187

    Google Scholar 

  • Solomos, N., Whitehead, M.J., Meaburn, J., Gondis, C.D., Christopoulou, P.E.: 1990,Astron. Astrophys. 229, 80

    Google Scholar 

  • Steidel, C.C., Sargent, W.L.W.: 1987,Astrophys. J. 313, 171

    Google Scholar 

  • Stocke, J.T., Liebert, J., Schmidt, G., Gioia, I., Maccacaro, T., Schild, R., Maccagni, D., Arp, H.: 1985,Astrophys. J. 298, 619

    Google Scholar 

  • Stocke, J.T., Morris, S.L., Gioia, I., Maccacaro, T., Schild, R.E., Wolter, A.: 1990,Astrophys. J. 348, 141

    Google Scholar 

  • Stockman, H.S., Moore, R.L., Angel, J.R.P.: 1984,Astrophys. J. 279, 485

    Google Scholar 

  • Sun, W.-H., Malkan, M.A.: 1987, inSupermassive Black Holes, ed. Kafatos, M., Cambridge Univ. Press, Cambridge, p. 273

    Google Scholar 

  • Sun, W.-H., Malkan, M.A.: 1989,Astrophys. J. 346, 68

    Google Scholar 

  • Tagliaferri, G., Stella, L., Maraschi, L., Treves, A., Morini, M.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 314

    Google Scholar 

  • Tanzi, E.G. et al.: 1986,Astrophys. J. Letters 311, L13

    Google Scholar 

  • Telesco, C.M.: 1988,Ann. Rev. Astron. Astrophys. 26, 343

    Google Scholar 

  • Telesco, C.M., Harper, D.A.: 1980,Astrophys. J. 235, 392

    Google Scholar 

  • Terasranta, H. et al.: 1987,Astron. Astrophys. Suppl. 71, 125

    Google Scholar 

  • Thompson, I.B., Martin, P.G.: 1988,Astrophys. J. 330, 121

    Google Scholar 

  • Thorne, K.S., Page, D.N.: 1974,Astrophys. J. 191, 507

    Google Scholar 

  • Treves, A., Chiapetti, L., Fabian, A., Falomo, R., Maccagni, D., Maraschi, L., Morini, M., Tanzi, E.G., Tagliaferri, G.: 1989,Astrophys. J. 341, 733

    Google Scholar 

  • Turner, T.J., Pounds, K.A.: 1988,Monthly Notices Roy. Astron. Soc. 232, 463

    Google Scholar 

  • Turner, T.J., Pounds, K.A.: 1989,Monthly Notices Roy. Astron. Soc. 240, 833

    Google Scholar 

  • Ulrich, M.-H.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 435

    Google Scholar 

  • Ulrich, M.-H., Courvoisier, T.J.-L., Wamsteker, W.: 1988,Astron. Astrophys. 204, 21

    Google Scholar 

  • Ulvestad, J.S., Wilson, A.S.: 1984,Astrophys. J. 285, 439

    Google Scholar 

  • Unger, S.W., Pedlar, A., Axon, D.J., Whittle, M., Meurs, E.J.A., Ward, M.J.: 1987,Monthly Notices Roy. Astron. Soc. 228, 671

    Google Scholar 

  • Urry, C.M., Kondo, Y., Hackney, K.R.H., Hackney, R.H.: 1988,Astrophys. J. 330, 791

    Google Scholar 

  • Urry, C.M., Mushotzky, R.F.: 1982,Astrophys. J. 253, 38

    Google Scholar 

  • Urry, C.M., Arnaud, K., Edelson, R.A., Kruper, J.S., Mushotzky, R.F.: 1990, in the proceedings of the23rd ESLAB Symposium: X-Ray Astronomy (in press)

  • Valtaoja, E., Haarala, S., Lehto, H., Valtaoja, L., Valtonen, M., Moiseev, I.G., Nesterov, N.S., Salonen, E., Terasranta, H., Urpo, S., Tiuri, M.: 1988,Astron. Astrophys. 203, 1

    Google Scholar 

  • Valtaoja, L., Sillanpaa, A., Valtaoja, E., Efimov, Y., Shakhavskoy, N.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 127

    Google Scholar 

  • van der Laan, H.: 1966,Nature 211, 1131

    Google Scholar 

  • Wade, R.A.: 1984,Monthly Notices Roy. Astron. Soc. 208, 381

    Google Scholar 

  • Walker, R.C., Benson, J.M., Unwin, S.C.: 1987, inSuperluminal Radio Sources, eds. Zensus, J.A., Pearson, T.J., Cambridge University Press, Cambridge, p. 48

    Google Scholar 

  • Wandel, A., Petrosian, V.: 1988,Astrophys. J. Letters 329, L1

    Google Scholar 

  • Wardle, J.F.C., Moore, R.L., Angel, J.R.P.: 1984,Astrophys. J. 279, 93

    Google Scholar 

  • Warwick, R.S., Koyama, K., Inoue, H., Takano, S., Awaki, H., Hoshi, R.: 1989,Pub. Astron. Soc. Japan 41, 739

    Google Scholar 

  • Webb, G.M., Drury, L.O'C, Biermann, P.: 1984,Astron. Astrophys. 137, 185

    Google Scholar 

  • Webb, J.R.: 1990,Astron. J. 99, 49

    Google Scholar 

  • Weedman, D.W.: 1983,Astrophys. J. 266, 479

    Google Scholar 

  • Weedman, D.W.: 1988,Nature 333, 208

    Google Scholar 

  • Wilkes, B.J., Elvis, M.: 1987,Astrophys. J. 323, 243

    Google Scholar 

  • Wills, B.J.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 109

    Google Scholar 

  • Wills, B.J., Netzer, H., Wills, D.: 1985,Astrophys. J. 288, 94

    Google Scholar 

  • Wilson, A.S.: 1988,Ast. Ap. 206, 41

    Google Scholar 

  • Wilson, A.S., Heckman, T.M.: 1985, inAstrophysics of Active Galaxies and Quasi-Stellar Objects, ed. Miller, J.S., University Science Books, Mill Valley, p. 39

    Google Scholar 

  • Wilson, A.S., Meurs, E.J.A.: 1982,Astron. Astrophys. Suppl. 50, 217

    Google Scholar 

  • Wilson, A.S., Ward, M.J., Haniff, C.A.: 1988,Astrophys. J. 334, 121

    Google Scholar 

  • Woltjer, L.: 1989, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 460

    Google Scholar 

  • Worrall, D.M.: 1987,Astrophys. J. 318, 188

    Google Scholar 

  • Worrall, D.M.: 1989a, inBL Lac Objects, eds. Maraschi, L., Maccacaro, T., Ulrich, M.-H., Springer, Berlin Heidelberg New York, p. 305

    Google Scholar 

  • Worrall, D.M.: 1989b,Proc. of the 23rd ESLAB Symposium (ESA SP-296), p. 719

  • Worrall, D.M. et al.: 1986,Astrophys. J. 303, 589

    Google Scholar 

  • Wright, G.S., Joseph, R.D., Meikle, W.P.S.: 1984,Nature 309, 430

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Astronomy Department, University of Michigan, Dennison Building, 48109-1090, Ann Arbor, MI, USA

    Joel N. Bregman

Authors
  1. Joel N. Bregman
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bregman, J.N. Continuum radiation from active galactic nuclei. The Astron Astrophys Rev 2, 125–166 (1990). https://doi.org/10.1007/BF00872765

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00872765

Key words

Search

Navigation