The black hole mass of the z=2.805 multiply imaged quasar SDSS J2222+2745 from velocity-resolved time lags of the C iv emission line
Abstract
We present the first results of a 4.5 yr monitoring campaign of the three bright images of multiply imaged z = 2.805 quasar SDSS J2222+2745 using the Gemini North Multi-Object Spectrograph and the Nordic Optical Telescope. We take advantage of gravitational time delays to construct light curves surpassing 6 yr in duration in the observed frame and achieve an average spectroscopic cadence of 10 days during the 8 months of visibility per season. Using multiple secondary calibrators and advanced reduction techniques, we achieve percent-level spectrophotometric precision and carry out an unprecedented reverberation mapping analysis, measuring both integrated and velocity-resolved time lags for the C iv emission line. The full line lags the continuum by Τ(cen)=36.5-3.9+2.9 rest-frame days. We combine our measurement with published C iv emission line lags and derive the r(BLR) - L relationship log10 (Τ/day)=(0.99 +/- 0.07)+(0.48 +/- 0.03)log10 [λLλ(1350AA)/1044erg s-1] with 0.30 +/- 0.06 dex intrinsic scatter. The velocity-resolved lags are consistent with circular Keplerian orbits, with Τ(cen)=86.2-5.0+4.5, 25-15+11 and 7.5-3.5+4.2 rest-frame days for the core, blue wing, and red wing, respectively. Using σline with the mean spectrum and assuming log10(fmean,σ)=0.52 +/- 0.26, we derive log10(MBH/M☉)=8.63 +/- 0.27 . Given the quality of the data, this system represents a unique benchmark for calibration of M-BH estimators at high redshift. Future work will present dynamical modeling of the data to constrain the virial factor f and MBH.
Citation
Williams , PR , Treu , T , Dahle , H , Valenti , S , Abramson , L , Barth , AJ , Dyrland , K , Gladders , M , Horne , K & Sharon , K 2021 , ' The black hole mass of the z =2.805 multiply imaged quasar SDSS J2222+2745 from velocity-resolved time lags of the C iv emission line ' , Astrophysical Journal , vol. 911 , no. 1 , 64 . https://doi.org/10.3847/1538-4357/abe943
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Rights
Copyright © 2021. The American Astronomical Society. All rights reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.3847/1538-4357/abe943
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 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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