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
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
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DOI：
10.3847/1538-4357/abe943
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发表时间：
2021-04
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通讯作者：
P. Williams;T. Treu;H. Dahle;S. Valenti;L. Abramson;A. Barth;K. Dyrland;M. Gladders;K. Horne;K. Sharon
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作者：
P. Williams;T. Treu;H. Dahle;S. Valenti;L. Abramson;A. Barth;K. Dyrland;M. Gladders;K. Horne;K. Sharon
我们提出的第一个4.5年的监测活动的三个明亮的图像的多重成像z = 2.805类星体SDSS J2222+2745使用双子座北多目标摄谱仪和北欧光学望远镜的结果。我们利用引力时间延迟来构建光变曲线，在观测帧中持续时间超过6年，并在每个季节8个月的可见度中实现平均10天的光谱节奏。使用多个二级校准器和先进的还原技术，我们实现了100级的分光光度精度，并进行了前所未有的混响映射分析，测量了C iv发射线的综合和速度分辨时间滞后。整条线比连续统滞后τcen=36.5−3.9+2.9个静止帧日。我们将我们的测量结果与已发表的Civ发射线滞后相结合，推导出r BLR − L关系log 10（τ/day）=（0.99±0.07）+（0.48±0.03）log 10 [λLλ（1350 AA）/1044 ergs −1]，内禀散射为0.30 ± 0.06 dex。速度分辨滞后与圆形开普勒轨道一致，核心、蓝翼和红翼的τcen分别为86.2−5.0+4.5、25−15+11和7.5−3.5+4.2静止帧天。使用平均光谱的σ线，并假设log 10（fmean，σ）=0.52±0.26，我们得出log 10（MBH/M）=8.63±0.27。鉴于数据的质量，该系统是一个独特的基准校准的M BH估计在高红移。未来的工作将提出动态建模的数据来约束维里因子f和M BH。
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 τcen=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)/1044ergs−1] with 0.30 ± 0.06 dex intrinsic scatter. The velocity-resolved lags are consistent with circular Keplerian orbits, with τcen=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 σ line 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 M BH.