An Axisymmetric Disk to Model Double-Peaked Hα Emission During Accretion in Tidal Disruption Events

Abstract

Tidal disruption events (TDEs) are some of the brightest and most fascinating astronomical transients to behold. A passing or orbiting star may wander within the tidal radius of a supermassive black hole and be tidally ripped apart from the immense gravitational pull. Debris and remnants of the star then eventually accrete, producing brilliant flares and spectroscopic emission that can be observed. In this paper, I present a multi-epoch spectroscopic analysis of four TDEs—AT 2018hyz, AT 2018dyb, AT 2019qiz, and AT 2020zso—that aims to model the evolution of their accretion disks. My work focuses on modeling TDE emission profiles around the Hα λ6564 region at different epochs. In a small subset of TDEs, the accretion disk may emit broad, double-peaked lines that provide great insight into their properties, and these objects are the valued in my sample. The model of choice in this analysis is the axisymmetric, optically thick and geometrically thin, relativistic disk. Optimizing the parameters and understanding the accretion process unlock meaningful information about the supermassive black hole and in turn the host galaxy and its evolution throughout the universe.