5 papers
Estimating redshift distributions of Fermi blazars with multiple machine-learning models
Kerui Zhu, Jiaming Chen, Yonggang Zheng +4
Approximately half of the Fermi-LAT-detected blazars lack spectroscopic redshift measurements, which limits population studies and investigations of the cosmological evolution of t…
Gaussian Process Modeling Coronal X-ray Variability of Active Galactic Nuclei
Haiyun Zhang, Dahai Yan, Li Zhang +1
The corona is an integral component of active galactic nuclei (AGNs) which can produce the X-ray emission. However, many of its physical properties and the mechanisms powering this…
Patterns of X-ray and -ray Flares: from Blazar to Maganetar and Sun
Haiyun Zhang, Dahai Yan, Lijuan Dong +6
Using Gaussian process methods, we analyzed the light curves of three extreme solar X-ray flares observed by the RHESSI satellite. Their variability characteristics were then compa…
Pattern and Origin for the Extreme -ray Flares of 3C 454.3 and 3C 279: An Astrophysical Critical Damper?
Haiyun Zhang, Dahai Yan, Jianeng Zhou +2
We apply a Gaussian process method to the extreme -ray flares of 3C 454.3 and 3C 279 to discover the variable patterns and then to investigate the physical origins of the giant…
Evidence for Magneto-gravitational Processes in Supermassive Black Hole Binary PG 1553+113
Haiyun Zhang, Dahai Yan, Li Zhang +1
PG1553+113 has drawn significant attention for its quasi-periodic oscillation (QPO) in gamma-ray variability, though the origin of its variability remains uncertain. In this study,…