Cygnus-A has been known for over two decades to be a strong source of X-ray emission. Imaging observations showed that this X-ray emission was predominantly from the hot gas associated with the cluster associated with the galaxy identified with the radio source. However, recent observations have shown that there is also absorbed non-thermal emission from the vicinity of the radio source. This has been identified with the emission expected from an active galactic nucleus being viewed through an absorbing torus. In this scenario a possible soft X-ray point source at the position of the radio core would be unobscured nuclear emission scattered into our line-of-sight.
The ASCA data presented here are performance verification phase data analyzed in collaboration with the rest of the satellite team.
REFERENCES
[1] Mushotzky, R.F., Done, C. & Pounds, K.A. 1993, Ann.Rev.Astr.Ap., 31, 717.
[2] Marshall, F.E., et al. 1993, Ap.J., 405, 168.
[3] Giacconi, R., Murray, S., Gursky, H., Kellogg, E., Schreier, E. & Tananbaum, H. 1972, Ap.J., 178, 281.
[4] Brinkmann, A.C., Heise, J., den Boggende, A.J.F., Grindlay, J., Gursky, H. & Parsignault, D. 1977, Ap.J., 214, 35.
[5] Fabbiano, G., Doxsey, R.E., Johnston, M., Schwartz, D.A. & Schwarz, J. 1979, Ap.J., 230, L67.
[6] Arnaud, K.A., Fabian, A.C., Eales, S.A., Jones, C. & Forman, W. 1984, MNRAS, 211, 981.
[7] Feigelson, E.D. & Schreier, E.J. 1979, Highlts.Astr., 5, 695.
[8] Arnaud, K.A., et al. 1987, MNRAS, 227, 241.
[9] Ueno, S., Koyama, K., Nishida, M., Yamauchi, S. & Ward, M.J. 1994, Ap.J., 431, L1.
[10] Mulchaey, J.S., Mushotzky, R.F. & Weaver, K.A. 1992, Ap.J., 390, L69.
[11] Harris, D.E., Perley, R. & Carilli, C. 1994, Multi-Wavelength Continuum Emission of AGN, eds Courvoisier, T. & Blecha, A., 375.
[12] Forman, W. & Jones, C. 1984, Ap.J., 276, 38.
[13] Tanaka, Y., Inoue, H. & Holt, S.S. 1994, Publ.Astr.Soc.Japan, 46, L37.
[14] Burke, B.E., et al. 1991, IEEE Trans., ED-38, 1069.
[15] Gendreau, K.C. 1995, Ph.D. Thesis, MIT.
[16] Kohmura, Y., et al. 1993, Proc. SPIE, 2006, 78.
[17] Krolik, J., Madau, P. & Zycki, P. 1994, Ap.J., 420, L57.
[18] Ghisellini, G., Haardt, F. & Matt, G. 1994, MNRAS, 267, 743.