THE CORRELATIONS BETWEEN THE CORE DOMINANCE PARAMETER AND THE CORE AND EXTENDED POWERS OF QUASARS

We study the correlations between the core dominance parameter R and t he core and extended powers P(core) and P-ext in the case of quasars w ith four different samples. In some samples, logP(ext) is highly anti- correlated with logR while logP(core) is not at all correlated with lo gR. This effect seems to be common in the case of quasars when R is no t very small. It obviously contradicts the conventional hypothesis of the core and extended emissions of radio sources in accordance with un ified schemes and beaming models. Our study also implies that when R b ecomes larger, the anti-correlation between logP(ext) and logR becomes more obvious while the correlation between logP(core) and logR become s less obvious; when R becomes smaller, the above anti-correlation bec omes less obvious while the correlation becomes more obvious. This eff ect can be interpreted by assuming that, for the lobe-dominated quasar s, the emission of the core is beamed and oriented, while for core-dom inated quasars, the emission of the core is unbeamed and isotropic.