See nemesispy.pdf for documentation.

NemesisPy contains routines for calculating and fitting exoplanet emission spectra at arbitrary orbital phases, which can help us constrain the thermal structure and chemical abundance of exoplanet atmospheres. It is also capable of fitting emission spectra at multiple orbital phases (phase curves) at the same time. This package comes ready with some spectral data and General Circulation Model (GCM) data so you can start simulating spectra immediately. There are a few demonstration routines in the nemesispy/examples folder; in particular, demo_fit_eclipse.py contains an interactive plot routine which allows you to fit a hot Jupiter eclipse spectrum by hand by varying its chemical abundance and temperature profile. This package can be easily integrated with a Bayesian sampler such as MultiNest for a full spectral retrieval.

The radiative transfer calculations are done with the correlated-k approximation, and are accelerated with the Numba just-in-time compiler to match the speed of compiled languages such as Fortran. The radiative transfer routines are based on the well-tested Nemesis (https://github.com/nemesiscode) library developed by Patrick Irwin (University of Oxford) and collaborators.

This package has the following features:

• Written fully in Python: highly portable and customisable compared to packages written in compiled languages and can be easily installed on computer clusters.
• Fast calculation speed: the most time consuming routines are optimised with just-in-time compilation, which compiles Python code to machine code at run time.
• Radiative transfer routines are benchmarked against the extensively used Nemesis (https://github.com/nemesiscode) library.
• Contains interactive plotting routines that allow you to visualise the impact of gas abundance and thermal structure on the emission spectra.
• Contains routines to simulate spectra from General Circulation Models (GCMs).
• Contains unit tests to check if the code is working correctly after modifications.

In order to install the package but still make it editable, change directory to the software folder and type the following in the terminal: pip install --editable .

To run all unit tests, change directory to the software folder and type the following in the terminal: python -m unittest discover test/