1999A&A...352...32C

In this paper, a method is proposed to determine the basic properties of γ-ray loud blazars, among them the central black hole mass, M, the Doppler factor, δ, the propagation angle of the γ-rays with respect to the symmetric axis of a two-temperature accretion disk, Φ, and the distance (i.e. the height above the accretion disk), d at which the γ-rays are created, for seven γ-ray loud blazars with available GeV variability timescales and in which the absorption effect of a γ-ray and the beaming effect have been taken into account. Our results indicate that, if we take the intrinsic γ-ray luminosity to be λ times the Eddington luminosity, L_γⁱⁿ=λL_Edd., the masses of the blazars are in the range of (4∼83)x10⁷M_☉ (λ=1.0) or (6∼131)x10⁷M_☉ (λ=0.1), the Doppler factors (δ) lie in the range of 0.57 to 3.72 (λ=1.0) or 0.79 to 5.33 (λ=0.1), the angle (Φ) is in the range of 14° to 43° (λ=1.0) or 13° to 39° (λ=0.1), and the distance (d) is in the range of 28R_g to 411R_g (λ=1.0) or 26R_g to 366R_g (λ=0.1). For 3C279, the case of a uniformly-bright disk is also adopted to determine the basic parameters, which are compared with those obtained for a two-temperature disk as well as those obtained by Becker & Kafatos (1995). Our model results are independent of γ-ray emission mechanisms but they do depend on the X-ray emission mechanism of the accretion disk.