摘要
本文对X射线选和射电选BL Lac型天体的射电、光学、X射线波段的单色光度进行相关性分析,发现X射线选的BL Lac天体只有射电与光学线性相关,而射电选BL Lac天体则X射线与射电、光学都相关。并在此基础上对射电选的BL Lac天体进行相对论修正后的相关性分析,得到了比修正前更好的相关性.因此,我们认为,两种选择的BL Lac型天体本质上是一样的;X射线流来自两种不同的辐射源;射电选的BL Lac型天体三波段流都有相对论提高。
Using the data given by Ghisellini et al. (i986) and Maraschi et al. (1986), we make a correlation analysis between the monochromatic radio (5GHz), optical (5500A) and X-ray luminosities for both X-ray selected BL Lac objects (XSs) and radio selected BL Lac objects (RSs). In the later sample, the blazars with strong lines (OVVs, HPQs) are in eluded.Correlations between radio and optical luminosities have been found in XSs and RSs, but the correlations of X-ray luminosity with radio and with optical luminosities appear only for RSs. Accepting the idea given by Xie et al. that BL Lac objects are beamed and the observed flux densities are enhanced by a factor δ3+α, where δ is the bulk relativiscic Doppler factor, the intrinsic the radio, optical and X-ray luminosities are deduced, and Stronger correlations between these intrinsic luminosities are found.We conclude that all BL Lac objects are beamed, and that the radio and optical fluxes are produced by the compact jet with the same mechanism, which is generally thought as synchro-tron radiation. While X-rays come from two components, one is isotopic radiation of non-synchrotron mechanism, the other is inverse compton scattering of radio and optical photons in the jet. The former components dominates the latter. RSs are intrinsically the same as XSSs. For RSs, whose jets exactly point to the observer, all the radio, optical and Compton X-ray radiations are relativistically boosted. The similar behavior of HPQs, OVVS suggests that their main mechanism is possibly the same as BL Lac objects.
基金
国家自然科学基金
