Relation between $\gamma$-rays and emission lines for the $\gamma$-ray loud blazars

Abstract

The relation between the $\gamma$-ray and the emission line luminosities for a sample of 36 $\gamma$-ray loud blazars is investigated; an apparent correlation between them, $L_{\gamma }\propto L_{Line}^{0.69\pm 0.11}$, with a correlation coefficient $r=0.741$ and a chance probability of $p=1.9\times 10^{-6}$, is found. It is found, however, that there is no intrinsic correlation between them: the apparent correlation is due to the redshift dependence in a flux-limited sample. Thus no evidence is found to support the argument that the up-scattered soft photons are from the broad emission lines. Our analysis does not conflict with the SSC model. The disk-jet symbiosis and radio/$\gamma$-ray correlation found in the literature are also discussed. The radio/$\gamma$-ray correlation may be an apparent correlation caused by the boosting effect since both bands are strongly beamed.

1 table, 2 figures, 4 pages, in A&A, 358, 841-844