• DOI:10.3847/2041-8213/ac081b
• Corpus ID: 232307679

Dynamical Modeling of the C iv Broad Line Region of the z = 2.805 Multiply Imaged Quasar SDSS J2222+2745

@article{Williams2021DynamicalMO,
  title={Dynamical Modeling of the C iv Broad Line Region of the z = 2.805 Multiply Imaged Quasar SDSS J2222+2745},
  author={Peter R. Williams and Tommaso Treu and H{\aa}kon Dahle and Stefano Valenti and Louis E. Abramson and Aaron J. Barth and Brendon J. Brewer and Karianne Dyrland and Michael D. Gladders and Keith D. Horne and Keren Sharon},
  journal={The Astrophysical Journal Letters},
  year={2021},
  volume={915}
}

• P. Williams, T. Treu, +8 authors K. Sharon
• Published 19 March 2021
• Physics
• The Astrophysical Journal Letters

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 ∼40° to the observer’s line of sight and with an emissivity weighted median radius of rmedian=33.0−2.1+2.4 light days. The kinematics are dominated by near-circular Keplerian motion with the remainder inflowing. The rest-frame lag one would measure from the models is τmedian=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 M BH measurement for any AGN at cosmological distances and it demonstrates that the precision required for BH-host coevolution studies is attainable.