The TDE Population from First-Principles Models of Stellar Disruption and Debris Dynamics

TL;DR

This paper develops a physically-grounded model for optical tidal disruption events (TDEs) using first-principles simulations and statistical inference, successfully reproducing observed distributions and predicting a large, mostly undetected population of low luminosity TDEs.

Contribution

It introduces a novel population model for TDEs based on hydrodynamic simulations and Bayesian inference, with no tunable emission parameters, and accounts for partial disruptions and stellar population effects.

Findings

The model matches observed TDE luminosity and black hole mass distribution.

Old stellar populations are strongly favored, with suppression of stars above 1.5-2 solar masses.

Partial disruptions account for about 30% of detected events and are crucial for reproducing observations.

Abstract

We present a physically-grounded population model for optical tidal disruption events (TDEs) that combines first-principles hydrodynamic simulations of stellar disruption with statistical inference of the underlying stellar and black hole populations. The model's prediction of peak luminosity is based directly on recent global simulations that follow the disruption self-consistently and contains no tunable parameters related to the emission physics. We construct the predicted joint distribution of peak luminosity and black hole mass, including both full and partial disruptions, and compare it to a sample of observed TDEs using Bayesian inference and Markov chain Monte Carlo sampling. We find that the model reproduces the distribution in the ($M_{BH},L_{peak}$) plane for the bulk of the observed TDE population with good statistical consistency. The data strongly favor an old stellar population, with a sharp suppression of stars above $M_* \simeq 1.5 - 2 M_\odot$. They also indicate that, at fixed stellar mass, the volumetric TDE rate is nearly independent of black hole mass. Partial disruptions contribute a substantial fraction ($\sim 30\%$) of detected events in flux-limited samples and are essential for reproducing the observed distribution. The inferred population properties are robust to different approximations to the stellar mass-radius relation, although the event rate at high luminosity is sensitive to the form of this relation for massive stars. We predict a large population of difficult to detect low luminosity TDEs, implying that the true volumetric TDE rate may exceed that inferred from present samples by up to an order of magnitude.