Astron. Astrophys. Suppl. Ser. 136, 13-18

The central black hole masses and Doppler factors of the $\gamma$-ray loud blazars

J.H. Fan^1,2 - G.Z. Xie ³ - R. Bacon ¹

1 - CRAL Observatoire de Lyon, 9 avenue Charles André, 69563 Saint-Genis-laval Cedex, France
2 - Center for Astrophysics, Guangzhou Normal University, Guangzhou 510400, China e-mail:jhfan@guangztc.edu.cn
3 - Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, China

Received June 30; accepted October 7, 1998

Abstract:

In this paper, the central black hole masses and the Doppler factors are derived for PKS 0528+134, PKS 0537-441, 3C 279, PKS 1406-074, PKS 1622-297, Q1633+382, Mkn 501, and BL Lacertae. The masses obtained are in the range of (1 - 7) $10^{7}~M_{\odot}$ and compared with that obtained with the Klein-Nishina cross section considered (Dermer & Gehrels 1995). If we considered only the Thomson cross section, the masses are in the range of $2.6\ 10^{6}~M_{\odot} - 2\ 10^{11}~M_{\odot}$. The masses obtained from our method are less sensitive to the flux than those obtained from Dermer & Gehrels (1995) method. The masses obtained from two flares (1991 and 1996 flares) of 3C 279 are almost the same. For 3C 279 and BL Lacertae, viewing angle, $\theta$, and Lorentz factor, $\Gamma$, are estimated from the derived Doppler factor and the measured superluminal velocity. For 3C 279, $\theta = 10\hbox{$.\!\!^\circ$}9-15\hbox{$.\!\!^\circ$}6$, $\Gamma = 2.4-14.4$ for $\delta$ = 3.37; $\theta = 8\hbox{$.\!\!^\circ$}45-9\hbox{$.\!\!^\circ$}7$, $\Gamma = 2.95-11.20$ for $\delta$ = 4.89; for BL Lacertae, $\theta = 25\hbox{$.\!\!^\circ$}-29\hbox{$.\!\!^\circ$}4$, $\Gamma = 2.0-4.0$.

Key words: black holes -- BL Lacertae objects -- galaxies: jets