solrat 1.0.0

Solar Radiative Transfer non-LTE forward-modeling code.

SolRaT

SolRaT (Solar Radiative Transfer) is a flexible forward modeling code for non-LTE transfer of radiation in stellar atmospheres.

The code provides a three-level framework for modeling radiative transfer:

1. Public API allows to run built-in RT models. Currently, SolRaT ships the non-LTE multi-term atom model (LL04) with multiple constant-slab atmosphere stratification.
2. Modeling API allows to extend existing models or create completely new ones.
3. SolRaT Engine introduces a meta-language that allows the user to write a human-readable code that directly resembles the underlying mathematical equations. The user does not need to focus on code optimization, as it is handled under the hood.

Key Features:

• Physics: Solves non-LTE radiative transfer for multi-term atoms.
• Magnetic Fields: Handles arbitrary magnetic field strengths (Zeeman, Hanle, Paschen-Back effects).
• Atmosphere: Supports multi-slab atmospheres for height stratification under anisotropic illumination (ATL08, HAZEL2).
• Flexibility: Provides a high-level meta-language allowing for writing code that directly resembles the underlying mathematical equations.
• Accessibility: SolRaT is free, open-source, and platform-independent.
• Performance: SolRaT uses high-performance libraries that leverage SIMD instruction sets.
• Extensibility: A clear Modeling API allows for quick prototyping and model adjustments for specific contexts.

How to run:

1. Install SolRaT from PyPi: pip install solrat
2. Explore the demos and tests for usage examples.
3. Explore the documentation.

Citing:

SolRaT is currently in beta testing. Journal article is pending and the detailed documentation is under development. In the meantime, if SolRaT has found use in your research, please cite it as

Yakovkin I. I. SolRaT (2023) [computer software]. Retrieved from https://www.yakovkinii.com/solrat/

References:

[LL04] Landi Degl’Innocenti, E., & Landolfi, M. 2004, Polarization in Spectral Lines (Dordrecht: Kluwer)

[ATL08] Asensio Ramos, A., Trujillo Bueno, J., & Landi Degl’Innocenti, E. (2008). Advanced Forward Modeling and Inversion of Stokes Profiles Resulting from the Joint Action of the Hanle and Zeeman Effects. The Astrophysical Journal, 683(1), 542–565.

[HAZEL2] Link

Keywords:

Non-LTE, Stokes Profiles, Inversion, Synthesis, Paschen-Back, Hanle, Zeeman, Magnetic Fields, Sun, Solar Atmosphere, Radiative Transfer, Polarization, Spectral Lines, Two-Term Atom Model

Copyright (2023) Ivan I. Yakovkin