We use 78 reverberation-measured Mg II time-lag quasars (QSOs) in the redshift range $0.0033 \leq z \leq 1.89$ to constrain cosmological parameters in six different cosmological models. The basis of our method is the use of the radius-luminosity or $R-L$ relation to standardize these 78 Mg II QSOs. In each cosmological model we simultaneously determine $R-L$ relation and cosmological model parameters, thus avoiding the circularity problem. We find that the $R-L$ relation parameter values are independent of the cosmological model used in the analysis thus establishing that current Mg II QSOs are standardizable candles. Cosmological constraints obtained using these QSOs are significantly weaker than, but consistent with, those obtained from a joint analysis of baryon acoustic oscillation (BAO) observations and Hubble parameter [$H(z)$] measurements. So, we also analyse these QSOs in conjunction with the BAO + $H(z)$ data and find cosmological constraints consistent with the standard spatially-flat $Λ$CDM model as well as with mild dark energy dynamics and a little spatial curvature. A larger sample of higher-quality reverberation-measured QSOs should have a smaller intrinsic dispersion and so should provide tighter constraints on cosmological parameters.
Standardizing reverberation-mapped H$β$ active galactic nuclei using time-averaged radius$-$luminosity relations with 5100\,Å\,, broad H$β$, and narrow \OIII\ luminosities
Kansas State University（堪萨斯州立大学）；Southern Methodist University（南方卫理公会大学）；Polish Academy of Sciences（波兰科学院）；Masaryk University（马萨里克大学）
Standardizing reverberation-mapped H$α$ and H$β$ active galactic nuclei using radius--luminosity relations involving monochromatic and broad H$α$ luminosities
Standardizing a larger, higher-quality, homogeneous sample of reverberation-mapped H$β$ active galactic nuclei using the broad-line region radius-luminosity relation
Reverberation lags viewed in hard X-rays from an accreting stellar-mass black hole
Wuhan University（武汉大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Newcastle University（纽卡斯尔大学）；Universitat Politècnica de Catalunya（加泰罗尼亚理工大学）；Beijing Normal University（北京师范大学）
AGN Reverberation Mapping with LITMUS: Fundamental Limits on lag Recovery Rates
University of Queensland（昆士兰大学）；Macquarie University（麦考瑞大学）；The Ohio State University（俄亥俄州立大学）；Stanford University（斯坦福大学）；Australian National University（澳大利亚国立大学）；The University of Sydney（悉尼大学）
Effects of heterogeneous data sets and time-lag measurement techniques on cosmological parameter constraints from MgII and CIV reverberation-mapped quasar data
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）
