Upgrading to Korg v1.0

This page explains the changes in Korg v1.0 that might trip you up if you are coming from an earlier version.

• synthesize, Korg.MolecularCrossSection, and Korg.prune_linelist now always take only a single argument for wavelength specification. Bounds can be passed as tuple, e.g. synthesize(atm, linelist, A_X, (λ_lower, λ_upper)). For synthesize, passing more than one argument will trigger a deprecation warning for now.
• Keyword arguments named m_H are now called M_H. This is more common notation, and is meant to look less like it means "hydrogen mass". This affects synth, Korg.Fit.ews_to_stellar_parameters, and Korg.Fit.fit_spectrum
• The default solar abundances (Korg.default_solar_abundances) are now Bergemann et al. 2025 (Korg.bergemann_2025_solar_abundances).
• The output units of flux are now erg/s/cm^4/Å, not erg/s/cm^5, which is more consistent with Korg's wavelength units.
• synth now requires that you specify at least Teff and logg. All other arguments are still optional.
• When synthesizing in the infrared, by default, the Mihalas-Daeppen-Hummer formalism is no longer used to self-consistently adjust hydrogen level populations for the purpose of bound-bound transitions. Previously, this was a warning.
• air_wavelengths is no longer an allowed keyword argument for Korg.synthesize. Users are recommended to use a workflow that involves explicit conversions with Korg.air_to_vacuum and Korg.vacuum_to_air. The old functionality is still available in Korg.Wavelengths, but this workflow can be confusing and we recommend avoiding it.
• The (previously deprecated) air_wavelengths keyword argument for Korg.synthesize has been removed.