Python Radiative Transfer Emission code (PYRATE): Non-local thermodynamic equilibrium spectral lines simulations

We describe Python Radiative Transfer Emission, a new, non-local thermodynamic equilibrium 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 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 and against analytical solutions and present case studies using hydrochemical simulations. The code is available on GITHUB.