Krang: Kerr Raytracer for Analytic NullGeodesics

Krang is a Julia (Bezanson et al., 2017) package that implements efficient algorithms for raytracing emission geometries in the Kerr black hole space time.It is GPU compatible and is specialized for studies of sub-image contributions from gravitationally lensed sources (Johnson et al., 2020).Such algorithms are of interest for modeling the sources seen by Very Long Baseline Interferometry (VLBI) observations of Low Luminosity Active Galactic Nuclei (LLAGN) such as those imaged by the Event Horizon Telescope Collaboration (EHTC).