| Issue |
A&A
Volume 671, March 2023
|
|
|---|---|---|
| Article Number | A171 | |
| Number of page(s) | 20 | |
| Section | Numerical methods and codes | |
| DOI | https://doi.org/10.1051/0004-6361/202244482 | |
| Published online | 23 March 2023 | |
PySME
Spectroscopy Made Easier★
1
Department of Physics and Astronomy, Uppsala University,
Box 516,
75120
Uppsala,
Sweden
e-mail: ansgar.wehrhahn@physics.uu.se
2
Institute of Astronomy of the Russian Academy of Sciences,
Pyatnitskaya str. 48,
119017
Moscow,
Russia
Received:
12
July
2022
Accepted:
9
December
2022
Context. The characterization of exoplanets requires the reliable determination of the fundamental parameters of their host stars. Spectral fitting plays an important role in this process. For the majority of stellar parameters, matching synthetic spectra to the observations provides a robust and unique solution for the fundamental parameters, such as effective temperature, surface gravity, abundances, radial and rotational velocities, among others.
Aims. Here, we present a new software package for fitting high-resolution stellar spectra that is easy to use, available for common platforms, and free from commercial licenses. We call it PySME. It is based on the proven Spectroscopy Made Easy package, later referred to as IDL SME or “original” SME.
Methods. The IDL (Interactive Data Language) part of the original SME code has been rewritten in Python, but we kept the efficient C++ and FORTRAN code responsible for molecular-ionization equilibrium, opacities, and spectral synthesis. In the process we updated some components of the optimization procedure to offer more flexibility and better analysis of the convergence. The result is a more modern package with the same functionality as the original SME.
Results. We applied PySME to a few stars of different spectral types and compared the derived fundamental parameters with the results from IDL SME and other techniques. We show that PySME works at least as well as the original SME.
Key words: techniques: spectroscopic / methods: data analysis / methods: numerical / stars: fundamental parameters / stars: solar-type
Table with the stellar parameters of the sample discussed in the paper is only available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/671/A171
© The Authors 2023
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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