2-6 September 2024
CJD Bonn Castell
Europe/Berlin timezone
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Contribution

CJD Bonn Castell

Windy or not: Radio pc-scale evidence for a broad-line region wind in radio-quiet quasars

Speakers

  • Dr. Sina CHEN

Primary authors

Co-authors

Content

Does a broad-line region (BLR) wind in radio-quiet (RQ) active galactic nuclei (AGN) extend to pc scales and produce radio emission associated with the BLR wind? We present the results of EVN (including e-MERLIN) observations at 1.7 and 4.9 GHz of ten (six detected) RQ Palomar-Green (PG) quasars, of which five were selected to have CIV blue excess wing and five without. Together with 13 RQ PG quasars detected in our earlier VLBA observations we find the following. All five objects with both radio and BLR winds are found at high Eddington ratios L/L_Edd (> 0.66), and eight of the nine objects without either radio or BLR winds reside at low L/L_Edd (< 0.28). This suggests that all BLR winds and most radio outflows in RQ AGN are related to a radiation pressure driven wind. The high L/L_Edd (= 2.0) in one of the nine no wind objects is probably overestimated due to a face-on view. Evidence for free-free absorption by the AGN photoionized gas, which flattens the spectral slope, is found in two objects. The radio outflow in three objects, which reside at very low L/L_Edd (= 0.05-0.12), is likely from a low-power jet, as suggested by additional evidence. Four intermediate L/L_Edd (= 0.2-0.4) objects may represent a mild equatorial BLR wind, which may be weakened in a face-on view or enhanced in an edge-on view. Future spectropolarimetry can test this inclination bias.