Bayesian rotation inversion of KIC 11145123

TL;DR

This paper develops a Bayesian rotation inversion method to analyze stellar rotational profiles, successfully validating it with artificial data and applying it to KIC 11145123, revealing a rapidly rotating core consistent with prior findings.

Contribution

The paper introduces a Bayesian scheme for stellar rotation inversion, providing a probabilistic framework and validation, and applies it to a hybrid star to infer core rotation speed.

Findings

The Bayesian scheme correctly distinguishes between different rotational models.

Application to KIC 11145123 suggests a core rotating ~10 times faster.

Results support previous 3-zone modeling conclusions.

Abstract

A scheme of Bayesian rotation inversion, which allows us to compute the probability of a model of a stellar rotational profile, is developed. The validation of the scheme with simple rotational profiles and the corresponding sets of artificially generated rotational shifts has been successfully carried out, and we can correctly distinguish the (right) rotational model, prepared beforehand for generating the artificial rotational shifts, with the other (wrong) rotational model. The Bayesian scheme is applied to a gamma Dor-delta Sct type hybrid star, KIC 11145123, leading to a result that the convective core of the star might be rotating much faster (~ 10 times faster) than the other regions of the star. The result is consistent with that previously suggested by Hatta et al. (2019) based on a 3-zone modeling, further strengthening their argument from a Bayesian point of view.