Basic properties of gamma-ray loud blazars

Abstract

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, Lin γ = λLEdd., the masses of the blazars are in the range of (4 ∼ 83) × 107 M⊙ (λ = 1.0) or (6 ∼ 131) × 107 M⊙ (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 28Rg to 411Rg (λ = 1.0) or 26Rg to 366Rg (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.