Dynamical modeling of the C iv broad line region of the z=2.805 multiply imaged quasar SDSS J2222+2745
Abstract
We present the first ever models of a broad line region (BLR) at the peak of active galactic nucleus (AGN) activity using the multiply imaged z = 2.805 quasar SDSS J2222+2745. The modeled data consist of monthly spectra covering the broad C IV emission line over a 5.3 yr baseline. The models suggest a thick disk BLR that is inclined by degrees 40 degrees to the observer's line of sight and with an emissivity weighted median radius of = rmedian = 33.0(-2.1)(+2.44) light days. The kinematics are dominated by near-circular Keplerian motion with the remainder inflowing. The restframe lag one would measure from the models is taumedian = 36.4(-1.8)(+1.8) days, which is consistent with measurements based on cross-correlation. We show a possible geometry and transfer function based on the model fits and find that the model-produced velocity-resolved lags are consistent with those from cross-correlation. We measure a black hole mass of log10(MBH/M⊙) = 8.31(-0.06)(+0.07), which requires a scale factor of log10 (fmean,σ) = 0.20(-0.07)(+0.09.). This is the most precise MBH measurement for any AGN at cosmological distances and it demonstrates that the precision required for BH-host coevolution studies is attainable.
Citation
Williams , P R , Treu , T , Dahle , H , Valenti , S , Abramson , L , Barth , A J , Brewer , B J , Dyrland , K , Gladders , M , Horne , K & Sharon , K 2021 , ' Dynamical modeling of the C iv broad line region of the z =2.805 multiply imaged quasar SDSS J2222+2745 ' , Astrophysical Journal Letters , vol. 915 , no. 1 . https://doi.org/10.3847/2041-8213/ac081b
Publication
Astrophysical Journal Letters
Status
Peer reviewed
ISSN
2041-8205Type
Journal article
Description
P.W. and T.T. gratefully acknowledge support by the National Science Foundation through grant AST-1907208 "Collaborative Research: Establishing the foundations of black hole mass measurements of AGN across cosmic time" and by the Packard Foundation through a Packard Research Fellowship to T.T. Research at UC Irvine was supported by NSF grant AST-1907290. K.H. acknowledges support from STFC grant ST/R000824/1.Collections
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