STELLAR AND GAS DYNAMICAL MODEL LOR TIDAL DISRUPTION EVENTS IN A QUIESCENT GALAXY

• Published in: The Astrophysical journal 2015-12, Vol.814 (2), p.1-20
• Main Authors: Mageshwaran, T, Mangalam, A
• Format: Article
• Language: English
• Subjects: Accretion disks; Debris; Disruption; Mathematical models; Stars; Tidal energy; Tidal power
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/814/2/141

A detailed model of the tidal disruption events (TDEs) has been constructed using stellar dynamical and gas dynamical inputs that include black hole (BH) mass M[bullet], specific orbital energy E and angular momentum J, star mass M[low *] and radius R, and the pericenter of the star orbit r sub(p)(E, J, M[bullet]). We solved the steady state Fokker-Planck equation using the standard loss cone theory for the galactic density profile [rho] (r) [is proportional to] r super(-[gamma]) and stellar mass function L (m) where m =M[low *]/M sub([middot in circle]) and obtained the feeding rate of stars to the BH integrated over the phase space as Nt [is proportional to] M[bullet] super([beta]), where [beta] = -0.3 + or - 0.01 for M[bullet] > 10 super(7)M sub([middot in circle]) and ~6.8 x 10 super(-5) Yr super(-1) for [gamma]= 0.7. We use this to model the in-fall rate of the disrupted debris, M(E, J, m, t), and discuss the conditions for the disk formation, finding that the accretion disk is almost always formed for the fiduciary range of the physical parameters. We also find the conditions under which the disk formed from the tidal debris of a given star with a super Eddington accretion phase. We have simulated the light curve profiles in the relevant optical g band and soft X-rays for both super and sub-Eddington accretion disks as a function of M(E, J, t). Using this, standard cosmological parameters, and mission instrument details, we predict the detectable TDE rates for various forthcoming surveys as a function of [gamma].