Radiative hydrodynamical simulations of super-Eddington accretion flow in tidal disruption event: the origin of optical/UV emission. Issue 2 (25th August 2022)

• Record Type: Journal Article
• Authors: Bu, De-Fu; Qiao, Erlin; Yang, Xiao-Hong; Liu, Jifeng; Chen, Zhiwei; Wu, Yongxin
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 516:Issue 2(2022)
• Page Start: 2833
• Page End: 2839
• Publication Date: 2022-08-25
• Subjects: accretion, accretion discs -- black hole physics -- radiative transfer -- transients: tidal disruption events; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac2399
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: One of the most prominent problems of optical/ultraviolet (UV) tidal disruption events (TDEs) is the origin of their optical/UV emission. It has been proposed that the soft X-rays produced by the stellar debris accretion disc can be reprocessed into optical/UV photons by a surrounding optically thick envelope or outflow. However, there is still no detailed models for this mechanism. In this paper, by performing hydrodynamic simulations with radiative transfer, we calculate the optical/UV emission of the circularized stellar debris accretion flow/outflow system. We find that the optical/UV photons can be generated by reprocessing the emission of the accretion flow in the optically thick outflows. The model can well interpret the observed emission properties of optical/UV TDEs, including the emission radius, the radiation temperature, and the blackbody luminosity, as well as the evolution of these quantities with time, providing a strong theoretical basis for understanding the origin of optical/UV TDEs.