Python Radiative Transfer Emission code (PyRaTE): non-LTE spectral lines simulations

TL;DR

PyRaTE is a Python-based non-LTE radiative transfer code designed for post-processing astrochemical simulations, capable of handling complex geometries and providing accurate spectral line predictions.

Contribution

It introduces a user-friendly, parallelized radiative transfer tool that integrates with various astrophysical simulation outputs and accurately computes optical depths in multiple directions.

Findings

Validated against RADEX and analytical solutions

Successfully applied to hydrochemical simulation case studies

Demonstrates versatility across geometries and projection angles

Abstract

We describe PyRaTE, a new, non-local thermodynamic equilibrium (non-LTE) line radiative transfer code developed specifically for post-processing astrochemical simulations. Population densities are estimated using the escape probability method. When computing the escape probability, the optical depth is calculated towards all directions with density, molecular abundance, temperature and velocity variations all taken into account. A very easy-to-use interface, capable of importing data from simulations outputs performed with all major astrophysical codes, is also developed. The code is written in Python using an `embarrassingly parallel' strategy and can handle all geometries and projection angles. We benchmark the code by comparing our results with those from RADEX (van der Tak et al. 2007) and against analytical solutions and present case studies using hydrochemical simulations. The code is available on GitHub (https://github.com/ArisTr/PyRaTE).