The correlations of multi-wave band luminosity and BLR luminosity in Fermi 2LAC blazars

We collect a sample of 78 Fermi detected blazars with broad line region (BLR) data and the quasi-simultaneous multi-wave band data. By analyzing the sample, we find: (1) For whole blazar sample, there exist significant correlations between radio, $\gamma$-ray luminosity and BLR luminosity. The slope of the best-fit linear regression equation is close to the theoretical value 1. Our results provided another support of jet-disk symbiosis. (2) For FSRQ sample, we find a significant correlation between radio luminosity and optical luminosity, and weaker correlations between X-ray luminosity and radio, optical luminosity. It indicates that the X-ray band radiation mechanism is slightly different from radio and optical bands. The X-ray emission is diluted by inverse Compton scattering (IC). There is a significant correlation between BLR luminosity and $\gamma$-ray luminosity, but no correlations between X-ray luminosity and BLR, $\gamma$-ray luminosity, which suggests that the seed soft photons are different for IC process. From these results we suggest that the X-ray band emission is diluted by synchrotron self-Compton (SSC) process, $\gamma$-ray band emission is produced by external Compton (EC) process.