Bayesian model selection for GRB 211211A through multi-wavelength analyses

TL;DR

This study uses Bayesian multi-wavelength analyses to evaluate possible progenitors of GRB 211211A, finding a preference for a binary neutron-star merger and highlighting the need for an r-process nucleosynthesis component to explain observations.

Contribution

It introduces a comprehensive Bayesian analysis framework to compare multiple astrophysical scenarios for GRB 211211A using multi-wavelength data.

Findings

Supports binary neutron-star merger as the likely progenitor.

Identifies the necessity of an r-process component in light curve modeling.

Provides statistical evidence favoring the neutron-star merger scenario.

Abstract

Although GRB 211211A is one of the closest gamma-ray bursts (GRBs), its classification is challenging because of its partially inconclusive electromagnetic signatures. In this paper, we investigate four different astrophysical scenarios as possible progenitors for GRB~211211A: a binary neutron-star merger, a black-hole--neutron-star merger, a core-collapse supernova, and an r-process enriched core collapse of a rapidly rotating massive star (a collapsar). We perform a large set of Bayesian multi-wavelength analyses based on different models describing these scenarios and priors to investigate which astrophysical scenarios and processes might be related to GRB~211211A. Our analysis supports previous studies in which the presence of an additional component, likely related to $r$-process nucleosynthesis, is required to explain the observed light curves of GRB~211211A, as it can not solely be explained as a GRB afterglow. Fixing the distance to about $350~\rm Mpc$, namely the distance of the possible host galaxy SDSS J140910.47+275320.8, we find a statistical preference for a binary neutron-star merger scenario.