The broadband spectral energy distributions ( SEDs ) of 18 GeV flat spectrum radio quasars ( FSRQs ) are collected and compiled from literature , in which both the jet emission and the accretion disk radiation can be observed , in order to investigate the correlations among their jet power ( P _ { jet } ) , accretion disk luminosity ( L _ { disk } ) , and luminosity of broad line region ( BLR , L _ { BLR } ) .
On the basis of the SED fits with the jet radiation and accretion disk radiation models , we calculate P _ { jet } and L _ { disk } .
No correlation between P _ { jet } with either L _ { disk } or L _ { BLR } is found .
With a sub-sample of L _ { BLR } for 13 GeV FSRQs , it is observed that L _ { BLR } is strongly correlated with their L _ { disk } .
We also study the BLR covering factors ( L _ { BLR } / L _ { disk } ) of the GeV FSRQs in our sample , averagely which are smaller than that of the large samples of radio-loud and radio-quiet quasars . P _ { jet } of some GeV FSRQs is higher than L _ { disk } , but P _ { jet } of all the GeV FSRQs is lower than the accretion power of black hole ( BH ) , which is estimated by \dot { M } c ^ { 2 } = L _ { disk } / 0.1 , indicating that the total accretion power of BH is sufficient to drive the jets in these sources ; however the uncorrelation between L _ { disk } and P _ { jet } of the GeV FSRQs may suggest that their jets are launched by the Blandford - Znajek process via extracting the rotational energy of BH .
Using the L _ { BLR } – L _ { disk } relation of the GeV FSRQs , we estimate L _ { disk } of a BL Lac sample with their L _ { BLR } .
A comparison of L _ { BLR } and Eddington ratio ( L _ { disk } / L _ { Edd } ) among BL Lacs , very radio-loud NLS1 galaxies , and FSRQs is also presented .
It is found that along with the BL Lac–NLS1–FSRQ sequence L _ { BLR } and L _ { disk } / L _ { Edd } increase , which may correspond to the change of the accretion disk structure and the transformation of the dominant mechanism for jet launching .
This is also consistent with the division of their parent populations , i.e. , low-excitation radio galaxies and high-excitation radio galaxies .