Individual Estimates of the Virial Factor in 10 Quasars: Implications on the Kinematics of the Broad Line Region

Abstract

Assuming a gravitational origin for the Fe III$\hat{I}»\hat{I}»$2039-2113 redshift and using microlensing based estimates of the size of the region emitting this feature, we obtain individual measurements of the virial factor, $f$, in 10 quasars. The average values for the Balmer lines, $⟨f_{H{\hat{I}}^2}⟩=0.43\pm 0.20$ and $⟨f_{H\hat{I}\pm }⟩=0.50\pm 0.24$, are in good agreement with the results of previous studies for objects with lines of comparable widths. In the case of Mg II, consistent results, $f_{MgII}\sim 0.44$, can be also obtained accepting a reasonable scaling for the size of the emitting region. The modeling of the cumulative histograms of individual measurements, $CDF(f)$, indicates a {relatively} high value for the ratio between isotropic and cylindrical motions, $a\sim 0.4-0.7$. On the contrary, we find very large values of the virial factor associated to the Fe III$\hat{I}»\hat{I}»$2039-2113 blend, $f_{FeIII}=14.3\pm 2.4$, which can be explained if this feature arises from a flattened nearly face-on structure, similar to the accretion disk.

Accepted in ApJ