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arXiv · 2408.15934

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

Sina Chen·Ari Laor·Ehud Behar·Ranieri D. Baldi·Joseph D. Gelfand·Amy E. Kimball·Ian M. McHardy·Gabor Orosz·Zsolt Paragi
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Abstract

Does a broad-line region (BLR) wind in radio-quiet (RQ) active galactic nuclei (AGN) extend to pc scales and produce radio emission? We explore the correlations between a pc-scale radio wind and the BLR wind in a sample of 19 RQ Palomar-Green (PG) quasars. The radio wind is defined based on the spectral slope and the compactness of the emission at 1.5-5 GHz, and the BLR wind is defined by the excess blue wing in the C IV emission line profile. The five objects with both radio and BLR wind indicators are found at high Eddington ratios L/L_Edd (> 0.66), and eight of the nine objects with neither radio nor BLR winds reside at low L/L_Edd (< 0.28). This suggests that the BLR wind and the radio wind in RQ AGN are related to a radiation pressure driven wind. Evidence for free-free absorption by AGN photoionized gas, which flattens the spectral slope, is found in two objects. Radio outflows in three low L/L_Edd (0.05-0.12) objects are likely from a low-power jet, as suggested by additional evidence. The presence of a mild equatorial BLR wind in four intermediate L/L_Edd (0.2-0.4) objects can be tested with future spectropolarimetry.

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Sina Chen, Ari Laor, Ehud Behar, Ranieri D. Baldi, Joseph D. Gelfand, Amy E. Kimball, Ian M. McHardy, Gabor Orosz, Zsolt Paragi. 2024-08-28. Windy or not: Radio pc-scale evidence for a broad-line region wind in radio-quiet quasars. https://arxiv.org/abs/2408.15934

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