Search Publications
A Possible 250 s X-Ray Quasi-periodicity in the Fast Blue Optical Transient AT2018cow
Tao, Lian; Zhang, Liang; Shu, Xinwen +11 more
The fast blue optical transients (FBOTs) are a new population of extragalactic transients of unclear physical origin. A variety of mechanisms has been proposed including failed supernova explosion, shock interaction with a dense medium, young magnetar, accretion onto a compact object and stellar tidal disruption event, but none is conclusive. Here…
A New X-Ray Tidal Disruption Event Candidate with Fast Variability
Greiner, J.; Komossa, S.; Erben, T. +3 more
During a close encounter between a star and a supermassive black hole, the star can get disrupted by the black hole's tidal forces, resulting in a tidal disruption event (TDE). The accretion of the star's material onto the black hole produces strong emission in different wavelength regimes. Here we report the discovery with the Roentgen Satellite …
B3 0749+460A: A New Repeat "Changing-look" Active Galactic Nucleus Associated with X-Ray Spectral Slope Variations
Filippenko, A. V.; Wang, J.; Gao, C. +5 more
Here we report an identification of B3 0749+460A as a new double-peaked local "changing-look" active galactic nucleus (CL-AGN) in terms of our multi-epoch spectroscopic analysis. By comparing our new spectra taken in 2021 with the ones taken by the Sloan Digital Sky Survey in 2004, BOSS in 2013 and MaNGA in 2016, we reveal type transitions of Seyf…
X-Ray and Radio Studies of the Candidate Millisecond Pulsar Binary 4FGL J0935.3+0901
Zheng, Dong; Wang, Zhong-Xiang; Xing, Yi +1 more
4FGL J0935.5+0901, a γ-ray source recently identified as a candidate redback-type millisecond pulsar (MSP) binary, shows an interesting feature of having double-peaked emission lines in its optical spectrum. This feature would further suggest the source is a transitional MSP system in the sub-luminous disk state. We have observed the source with X…
A Study on White Dwarf Masses in Cataclysmic Variables Based on XMM-Newton and Suzaku Observations
Li, Xiang-Dong; Xu, Xiao-Jie; Yu, Zhuo-Li
The distribution of the mass of white dwarfs (WDs) is one of the fundamental questions in the field of cataclysmic variables (CVs). In this work, we make a systematical investigation on the WD masses in two subclass of CVs: intermediate polars (IPs) and non-magnetic CVs in the solar vicinity based on the flux ratios of Fe XXVI-Lyα to Fe XXV-Heα em…
The Origin of The Soft X-Ray Excess in the Seyfert 1.5 Galaxy ESO 362-G18
Zhong, Xiao-Gu; Wang, Jian-Cheng
We review the Seyfert 1.5 Galaxy ESO 362-G18 for exploring the origin of the soft X-ray excess. The Warm Corona and Relativistic Reflection models are two main scenarios to interpret the soft X-ray excess in active galactic nuclei at present. We use the simultaneous X-ray observation data of XMM-Newton and NuSTAR on 2016 September 24 to perform sp…