We present results of broad band photometric reverberation mapping (RM) to measure the radius of the broad line region, and subsequently the black hole mass (M$_{\rm BH}$), in the nearby, low luminosity active galactic nuclei (AGN) NGC 4395. Using the Wise Observatory's 1m telescope equipped with the SDSS g$'$, r$'$ and i$'$ broad band filters, we monitored NGC 4395 for 9 consecutive nights and obtained 3 light curves each with over 250 data points. The g$'$ and r$'$ bands include time variable contributions from H$β$ and H$α$ (respectively) plus continuum. The i$'$ band is free of broad lines and covers exclusively continuum. We show that by looking for a peak in the difference between the cross-correlation and the auto-correlation functions for all combinations of filters, we can get a reliable estimate of the time lag necessary to compute M$_{\rm BH}$. We measure the time lag for H$α$ to be $3.6 \pm 0.8 $ hours, comparable to previous studies using the line resolved spectroscopic RM method. We argue that this lag implies a black hole mass of M$_{\rm BH} = (4.9 \pm 2.6) \times 10^{4}$ \Msun .
Consistency between X-ray and UV-Optical reverberation measurements in NGC 5548
Center for Theoretical Physics, Polish Academy of Sciences（波兰科学院理论物理中心）；Astronomical Institute of the Czech Academy of Sciences（捷克科学院天文研究所）；Cahill Center for Astronomy & Astrophysics, California Institute of Technology（加州理工学院卡希尔天体物理学与天文学中心）；Department of Physics and Institute of Theoretical and Computational Physics, University of Crete（克里特大学物理系与理论与计算物理研究所）；Institute of Astrophysics, FORTH（FORTH天体物理研究所）
The Size, Structure and Ionization of the Broad Line Region in NGC 3227
哈勃太空望远镜（HST）对塞弗特1.5星系（NGC 3227）的光谱分析证实了先前的报告，即宽H-α发射线通量是随时间变化的，在1999年至2000年之间减少了11%，对应的是基础连续谱减少了37%。模拟的气体分布负责广泛的H-α，H-β和H-γ发射线有利于一个球对称的流入，而不是薄盘。根据先前的混响映射，采用中心黑洞质量为7.6 x 10^{6} Msun，可以得出发射宽H-α线的区域尺寸如下：外半径约为90 l.d，内半径约为3 l. d。因此，先前确定的宽线区域（BLR）的混响大小始终与更大体积的电离气体的内径一致。然而，感知到的BLR的大小是一种错觉，这是由于发射区域在外半径处被电离束缚并且在内半径处被多普勒展宽减小的事实的结果。流入的实际尺寸仍有待确定。尽管如此，稳态质量流入速率估计为~ 10^{-2} Msun/yr，这足以解释活动星系核的X射线光度是辐射无效吸积的结果。总的来说，这些结果挑战了许多关于活动星系核中BLR性质的先入为主的观念。
Discovery of a Luminosity-dependent Continuum Lag in NGC 4151 from Photometric and Spectroscopic Continuum Reverberation Mapping
Yunnan Observatories, Chinese Academy of Sciences（中国科学院云南天文台）；Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences（中国科学院天体结构与演化重点实验室）；Center for Astronomical Mega-Science, Chinese Academy of Sciences（中国科学院天文大科学研究中心）；Key Laboratory of Radio Astronomy and Technology, Chinese Academy of Sciences（中国科学院射电天文与技术重点实验室）；Department of Astronomy, Xiamen University（厦门大学天文学系）；Institute of Space Sciences (ICE, CSIC)（空间科学研究所（IEE-CSIC））；Jeremiah Horrocks Institute, University of Central Lancashire（中央兰开夏大学杰里迈亚·霍罗克斯研究所）；School of Physics and Astronomy, Sun Yat-sen University（中山大学物理与天文学院）；CSST Science Center for the Guangdong-Hong Kong-Macau Greater Bay Area（粤港澳大湾区空间站科学中心）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）
HALO I: Photometric continuum reverberation mapping of Fairall 9
Center for Theoretical Physics, Polish Academy of Sciences（波兰科学院理论物理中心）；Heidelberg Institute for Theoretical Studies（海德堡理论研究所）；Institut d’Astrophysique et de Géophysique, Université de Liège（列日大学天体物理学与地球物理研究所）；International Gemini Observatory/NSF NOIRLab（国际双子座天文台/NSF NOIRLab）；Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences（波兰科学院尼古拉·哥白尼天文中心）；Universidad de Concepción（孔塞普西翁大学）；Aryabhatta Research Institute of Observational Sciences（阿亚波达观测科学研究所）；Department of Applied Physics/Physics, Mahatma Jyotiba Phule Rohilkhand University（马哈特玛·乔蒂巴·富勒罗希尔坎德大学应用物理/物理系）；Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University（马萨里克大学理学院理论与天体物理学系）
