Creating and using large grids of pre-calculated model atmospheres for rapid analysis of stellar spectra

TL;DR

This paper introduces a comprehensive database of 45,000 stellar atmosphere models covering massive stars, with synthetic spectra across multiple wavelengths, enabling rapid spectral analysis and re-evaluation of stellar parameters.

Contribution

The authors created an extensive, multi-dimensional grid of pre-calculated stellar atmosphere models and synthetic spectra, facilitating quick analysis of stellar spectra and re-assessment of stellar properties.

Findings

Database contains 45,000 models, expandable to 80,000.

Synthetic spectra cover UV, optical, and IR regions.

Re-analysis of epsilon Ori demonstrates the database's utility.

Abstract

We present a database of 45,000 atmospheric models (which will become 80,000 models by the end of the project) with stellar masses between 9 and 120 M$_{\odot}$, covering the region of the OB main sequence and W-R stars in the H-R diagram. The models were calculated using the ABACUS I supercomputer and the stellar atmosphere code CMFGEN. The parameter space has 6 dimensions: the effective temperature $T_{\rm eff}$, the luminosity $L$, the metallicity $Z$, and three stellar wind parameters, namely the exponent $\beta$, the terminal velocity $V_{\infty}$, and the volume filling factor $F_{cl}$. For each model, we also calculate synthetic spectra in the UV (900-2000 Angstroms), optical (3500-7000 Angstroms), and near IR (10000-30000 Angstroms) regions. To facilitate comparison with observations, the synthetic spectra were rotationally broaden using ROTIN3, by covering $v$ sin $i$ velocities between 10 and 350 km/s with steps of 10 km/s, resulting in a library of 1 575 000 synthetic spectra. In order to demonstrate the benefits of employing the databases of pre-calculated models, we also present the results of the re-analysis of $\epsilon$ Ori by using our grid.