Flow-Based Generative Emulation of Grids of Stellar Evolutionary Models

Fuente: arXiv
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Auteurs principaux: Hon, Marc, Li, Yaguang, Ong, Joel
Format: Preprint
Publié: 2024
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author Hon, Marc
Li, Yaguang
Ong, Joel
author_facet Hon, Marc
Li, Yaguang
Ong, Joel
contents We present a flow-based generative approach to emulate grids of stellar evolutionary models. By interpreting the input parameters and output properties of these models as multi-dimensional probability distributions, we train conditional normalizing flows to learn and predict the complex relationships between grid inputs and outputs in the form of conditional joint distributions. Leveraging the expressive power and versatility of these flows, we showcase their ability to emulate a variety of evolutionary tracks and isochrones across a continuous range of input parameters. In addition, we describe a simple Bayesian approach for estimating stellar parameters using these flows and demonstrate its application to asteroseismic datasets of red giants observed by the Kepler mission. By applying this approach to red giants in open clusters NGC 6791 and NGC 6819, we illustrate how large age uncertainties can arise when fitting only to global asteroseismic and spectroscopic parameters without prior information on initial helium abundances and mixing length parameter values. We also conduct inference using the flow at a large scale by determining revised estimates of masses and radii for 15,388 field red giants. These estimates show improved agreement with results from existing grid-based modelling, reveal distinct population-level features in the red clump, and suggest that the masses of Kepler red giants previously determined using the corrected asteroseismic scaling relations have been overestimated by 5-10%.
format Preprint
id arxiv_https___arxiv_org_abs_2407_09427
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Flow-Based Generative Emulation of Grids of Stellar Evolutionary Models
Hon, Marc
Li, Yaguang
Ong, Joel
Solar and Stellar Astrophysics
Astrophysics of Galaxies
Machine Learning
We present a flow-based generative approach to emulate grids of stellar evolutionary models. By interpreting the input parameters and output properties of these models as multi-dimensional probability distributions, we train conditional normalizing flows to learn and predict the complex relationships between grid inputs and outputs in the form of conditional joint distributions. Leveraging the expressive power and versatility of these flows, we showcase their ability to emulate a variety of evolutionary tracks and isochrones across a continuous range of input parameters. In addition, we describe a simple Bayesian approach for estimating stellar parameters using these flows and demonstrate its application to asteroseismic datasets of red giants observed by the Kepler mission. By applying this approach to red giants in open clusters NGC 6791 and NGC 6819, we illustrate how large age uncertainties can arise when fitting only to global asteroseismic and spectroscopic parameters without prior information on initial helium abundances and mixing length parameter values. We also conduct inference using the flow at a large scale by determining revised estimates of masses and radii for 15,388 field red giants. These estimates show improved agreement with results from existing grid-based modelling, reveal distinct population-level features in the red clump, and suggest that the masses of Kepler red giants previously determined using the corrected asteroseismic scaling relations have been overestimated by 5-10%.
title Flow-Based Generative Emulation of Grids of Stellar Evolutionary Models
topic Solar and Stellar Astrophysics
Astrophysics of Galaxies
Machine Learning
url https://arxiv.org/abs/2407.09427