gcepy

Code for sampling for testing models of the Galactic center excess (GCE).

This code relies on jax for all basic definitions, building up to a log-likelihood for the model given the data.

There are separate modules for a "low-dimensional" (astrophysically motivated) 5-parameter model based on 2112.09706 and a "high-dimensional" (ring-based) 19-parameter model based on 2209.00006. Models and data related to 2112.09706 are included here. Model files based on the ring-based models of 2209.00006 (and Pohl et al.) are available on request.

installation and usage

To install, clone the repository and run python -m pip install . as normal.

To load and use the "low-dimensional" model the preferred method is

import gcepy
from jax import numpy as jnp
gcepy.lnlike('low', jnp.ones(5))

or the following is equivalent:

import gcepy
from jax import numpy as jnp
gcepy._lm.jjlnprob(jnp.ones(5))

See the included ipython notebook for a more involved example, including runs with both dynesty (nested sampling) and numpyro (hamiltonian monte carlo no-u-turn sampler) to obtain parameter posteriors in a single energy bin (and now a bonus section using the microcanonical hamiltonian monte carlo!).

citation

If you use this module in your research please add a footnote to this repository and cite 2112.09706 and 2209.00006 and any other relevant work.