Grackle

Grackle is a chemistry and radiative cooling library for astrophysical simulations and models. Grackle has interfaces for C, C++, Fortran, and Python codes and provides:

• two options for primordial chemistry and cooling:

  1. non-equilibrium primordial chemistry network for atomic H, D, and He as well as H₂ and HD, including H₂ formation on dust grains.

  2. tabulated H and He cooling rates calculated with the photo-ionization code, Cloudy.

• tabulated metal cooling rates calculated with Cloudy.

• photo-heating and photo-ionization from two UV backgrounds with optional self-shielding corrections:

  1. Faucher-Giguere et al. (2009).

  2. Haardt & Madau (2012).

• support for user-provided arrays of volumetric and specific heating rates.

The Grackle provides functions to update chemistry species; solve radiative cooling and update internal energy; and calculate cooling time, temperature, pressure, and ratio of specific heats (gamma).

For more information on features, installation, and integration with simulation codes and models, see our online documentation.

Resources

• documentation: https://grackle.readthedocs.io/

• source code repository: https://github.com/grackle-project/grackle

• method paper: Smith et al. (2017)