Correlation Analysis for Gamma-ray (radio) and Broad Line Emissions of
  Fermi Blazars
  In this work, we compiled a sample of 202 Fermi/LAT blazars with available
broad line emissions. Out of the 202 sources, 66 have known Doppler factors.
The correlation between ($\gamma$-ray) and broad-line emission, and that
between radio and broad-line emission are investigated by removing the effects
of redshift and beaming boosting for the whole sample and the subclasses, flat
spectrum radio quasars (FSRQs) and BL Lacertae objects (BL Lacs) respectively.
We obtained a strong positive correlation between ($\gamma$-ray) and broad-line
emission and between radio and broad-line emission for the 202 blazars; It is
worth noting that the correlation still exists after removing redshift effect.
For the 66 sources with Doppler factors, there is also a positive correlation
between ($\gamma$-ray) and broad-line emission after removing the Doppler
factors, as well as that between radio and broad-line emission. Our analysis
suggest that 1. There are strong correlations between the ($\gamma$-ray) and
the broad line emission for the whole blazar sample and their subclasses. The
correlations exist when the redshift effect is removed for the whole sample and
their subclasses, confirming the results by Ghisellini et al. (2014) and Chen
(2018). 2. For the 66 blazars with available Doppler factors, a strong
correlation between the broad line emission and the Doppler factor is found.
The correlation between the ($\gamma$-ray) and the broad line emission exists
after the Doppler factor effect is removed. Similar results for 1 and 2 also
obtained between radio and broad-line emission. 3. Our analysis suggests a
robust connection between the accretion process and the jet.
