We construct a three-dimensional and redshift-evolutionary X-ray and ultraviolet (LX−LUV) luminosity relation for quasars from the powerful statistic tool called copula, and find that the constructed LX−LUV relation from copula is more viable than the standard one and the observations favor the redshift-evolutionary relation more than 3σ. The Akaike and Bayes information criterions indicate that the quasar data support strongly the three-dimensional LX−LUV relation. Our results show that the quasars can be regarded as a reliable indicator of the cosmic distance if the LX−LUV relation from copula is used to calibrate quasar data.
@article{arxiv.2210.14432,
title = {Redshift-evolutionary X-ray and UV luminosity relation of quasars from Gaussian copula},
author = {Bao Wang and Yang Liu and Zunli Yuan and Nan Liang and Hongwei Yu and Puxun Wu},
journal= {arXiv preprint arXiv:2210.14432},
year = {2022}
}
Comments
15 pages, 6 figures. Accepted for publication in ApJ