HELIOS is an open-source radiative transfer code, which is constructed for studying exoplanetary atmospheres in their full variety. The model atmospheres are one-dimensional and plane-parallel, and the equation of radiative transfer is solved in the hemispheric two-stream approximation with non-isotropic scattering. For given opacities and planetary parameters, HELIOS finds the atmospheric temperature profile in radiative-convective equilibrium and the corresponding planetary emission spectrum.
HELIOS is part of the Exoclimes Simulation Platform (ESP).
If you use HELIOS for your own work, please cite its two method papers: Malik et al. 2017 and Malik et al. 2019a. If you use the solid surface feature, please also cite the papers describing its implementation, namely Malik et al. 2019b and Whittaker et al. 2022.
Any questions, issues or bug reports are appreciated and can be sent to malik@umd.edu.
Thank you for considering HELIOS!
New features include:
- option to add a non-gray surface albedo, self-consistently incorporated into the atmospheric RT (with option to run a bare-rock case without atmosphere).
- option to mix opacities on-the-fly instead of using a premixed opacity table.
- option to read vertical mixing ratios instead of (or in addition to) equilibrium chemistry.
- option to couple to photochemical kinetics codes.
- option to use Random Overlap (RO) to mix opacities of individual species (previously only correlated-k possible).
- option to include multiple, parameterized cloud decks. Mie-scattering input files are provided.
- option to use physical time stepping with given runtime.
- improved T-P smoothing functionality that satisfies global energy conservation.
- script to easily produce stellar spectrum input files from common databases like PHOENIX.
- (almost) all input parameters are now as command-line options available.
- completely revised "ktable" program. It is now possible to generate k-distribution tables directly from HELIOS-K output files.
- enhanced overall clarify, user-friendliness and automatization based on input options.
A detailed documentation of HELIOS can be found here.