Bayesian Analysis of Massive Boson Star Models for Sagittarius A* Using Near-Infrared Astrometry Data

TL;DR

This study uses Bayesian analysis of near-infrared astrometry data to compare boson star and black hole models for Sagittarius A*, finding them statistically indistinguishable with current data.

Contribution

First comprehensive Bayesian comparison of boson star and black hole models for Sagittarius A* using near-infrared data and multiple configurations.

Findings

Bayesian evidence values are marginally different between models.

Mass estimates of Sgr A* are consistent across models.

Current data cannot statistically distinguish between boson star and black hole.

Abstract

Assuming that the compact source at the Galactic center, Sagittarius A*, is a massive boson star, we fit the near-infrared flare astrometry data. We consider 12 discrete boson star configurations and model the flare as a hotspot on a circular equatorial orbit. The analysis is performed in a Bayesian framework using nested sampling, yielding the marginal posterior distributions of all parameters as well as the Bayesian evidence for each model. For comparison, the same procedure is applied to a Schwarzschild black hole. The resulting Bayesian evidence values differ only marginally between the boson star and black hole cases, and the well-determined mass of Sgr~A* (${\sim}4.296\times 10^6\,M_\odot$) falls within the 68\% highest density interval in every configuration. We conclude that, under current near-infrared astrometric constraints and within the considered parameter ranges, a massive boson star and a Schwarzschild black hole remain statistically indistinguishable as the compact object at the Galactic center.