论文标题
宽线射电星系3C 120的机器人混响映射
Robotic reverberation mapping of the broad-line radio galaxy 3C 120
论文作者
论文摘要
我们从2016年12月至2018年4月对LAS CUMBRES天文台（LAS Cumbres天文台（LAS）全球机器人望远镜网络进行了良好研究的宽线射电星系3C 120的光度和光谱观测，这是LCO AGN关键项目在收获流的回响映射的一部分。在这里，我们介绍了光谱和光度混响映射结果。我们使用插值互相关函数（ICCF）在3C 120中执行多线滞后测量。我们找到了H $γ$，He II $λ4686$，H $β$，HE I $λ5876$ lags $ $τ_{ $ 2.7 _ { - 0.8}^{+0.7} $，$ 21.2 _ { - 1.0}^{+1.6} $，$ 16.9 _ { - 1.1}^{+0.9} $ days $ nover相对于V-Band Continum。使用H $β$发射线的测得的滞后和RMS速度宽度，我们确定3C 120的黑洞的质量为$ M = \左（6.3^{+0.5} _ { - 0.3} \ right）\ times10^7 \ 7 \，（f/5.5）$ m $ _ $ _ $ _ \ odot $。我们的黑洞质量测量与3C 120的先前研究相似，但不确定性很小。此外，3C 120中速度分辨的滞后滞后显示了H $β$线上的对称模式，在线中心的25天在线翼上的17天降至17天，$ \ pm4000 $ km S $^{ - 1} $。我们还研究了3C 120中的频段连续滞后滞后，发现它们通常与$τ\proptoλ^{4/3} $一致，如从几何形式薄的，光学厚的积聚盘所预测的。从连续滞后，我们测量最佳拟合值$τ_ {\ rm 0} = 3.5 \ pm 0.2 $ days $λ_{\ rm 0} = 5477 $ a。它意味着光盘尺寸的$ 1.6 $ $ 1.6 $ $ 1.6 $倍，比标准光盘模型的预测大于$ l/l _ {\ rm edd} = 0.4 $。这与先前测量比预期的圆盘大小更大的研究一致。
We carried out photometric and spectroscopic observations of the well-studied broad-line radio galaxy 3C 120 with the Las Cumbres Observatory (LCO) global robotic telescope network from 2016 December to 2018 April as part of the LCO AGN Key Project on Reverberation Mapping of Accretion Flows. Here, we present both spectroscopic and photometric reverberation mapping results. We used the interpolated cross-correlation function (ICCF) to perform multiple-line lag measurements in 3C 120. We find the H$γ$, He II $λ4686$, H$β$ and He I $λ5876$ lags of $τ_{\text{cen}} = 18.8_{-1.0}^{+1.3}$, $2.7_{-0.8}^{+0.7}$, $21.2_{-1.0}^{+1.6}$, and $16.9_{-1.1}^{+0.9}$ days respectively, relative to the V-band continuum. Using the measured lag and rms velocity width of the H$β$ emission line, we determine the mass of the black hole for 3C 120 to be $M=\left(6.3^{+0.5}_{-0.3}\right)\times10^7\,(f/5.5)$ M$_\odot$. Our black hole mass measurement is consistent with similar previous studies on 3C 120, but with small uncertainties. In addition, velocity-resolved lags in 3C 120 show a symmetric pattern across the H$β$ line, 25 days at line centre decreasing to 17 days in the line wings at $\pm4000$ km s$^{-1}$. We also investigate the inter-band continuum lags in 3C 120 and find that they are generally consistent with $τ\proptoλ^{4/3}$ as predicted from a geometrically-thin, optically-thick accretion disc. From the continuum lags, we measure the best fit value $τ_{\rm 0} = 3.5\pm 0.2$ days at $λ_{\rm 0} = 5477$A. It implies a disc size a factor of $1.6$ times larger than prediction from the standard disc model with $L/L_{\rm Edd} = 0.4$. This is consistent with previous studies in which larger than expected disc sizes were measured.
