γ噪Blazar天体的γ射线和近红外光辐射研究

收集了29个有γ噪的Blazar天体(其中有16个BL Lac天体和13个平谱射电类星体)的近红外流量密度和γ射线流量密度,获得以下主要结果:1)23个天体中的γ射线流量密度和近红外流量密度在低态时存在较强的相关性而在高态时有弱的相关性.2)在29个天体中,有6个天体只有一个观测数据点,将其认为是高态时,γ射线流量密度与近红外光流量密度之间有弱相关性,而认为是低态时有强相关性.3)29个源的γ射线流量密度与X射线流量密度在低态时有相关性,但是γ射线流量与光学流量密度,γ射线流量与射电流量密度均没有相关性.4)在16个BL Lac天体中γ射线流量与近红外光流量不论在高态还是低态都有相关性,而13个平谱射电类星体没有相关性.讨论了γ噪Blazar天体的γ射线辐射机制,认为γ射线的辐射机制主要是同步自康普顿散射.而逆康普顿散射来自绕中心核且温度约为2000K的尘埃,这些尘埃的区域大约有r=3pc,聚束的相对论电子也可能是这种尘埃模型辐射机制的一个重要补充.平谱射电类星体和BL Lac天体的γ辐射机制可能有些不同. 关键词： Blazar天体 星系γ射线观测辐射机制 非热辐射

STUDY OF GAMMA-RAY AND NEAR-INFRARED EMISSION OF GAMMA-RAY-LOUD BLAZARS OBJECT

We have collected 29 gamma-ray-loud blazars (16 BL Lac objects and 13 flat-spectrum radio quasars) with both observed near-IR and γ-ray flux densitees, with the following main results:(1)there is a very strong correlation between Fγ and FIR in the low state, and a weaker but also significant correlation between Fγ and FIR in the high state for 23 objects with both high and low state fluxes; (2) there is a very significant correlation between Fγ and FIR in the low state, and a weak correlation between Fγ and FIR in the high state for 29 sources; (3) there is a correlation between Fγ and Fx, but not between Fγ and FO, and FR for both the low and high state of 26 sources; (4) there is a strong correlation between Fγ and FIR in the low and high states for 15 BL Lac objects, but not for 11 flat-spectrum radio quasars. Possible constraints on the γ-ray emission mechanism are discussed. We suggest that the main gamma-ray radiation mechanism is probably the synchrotron self-Compton process. The inverse Compton scattering of the radiation from hot circumnuclear dust with Tg=2000K, which is located within the region of r≈3pc, by beamed ultrarelativistic electrons is likely to be an important complementary mechanism. In addition, the γ-ray emission may be somewhat different for BL Lac objects and flat-spectrum radio quasars.