Public Release of RELXILL_NK: A Relativistic Reflection Model for Testing Einstein's Gravity

Understand

We present the public release version of relxill_nk, an X-ray reflection model for testing the Kerr hypothesis and general relativity.

• This model extends the relxill model that assumes the black hole spacetime is described by the Kerr metric.
• We also present relxilllp_nk, the first non-Kerr X-ray reflection model with a lamppost corona configuration, as well as all other models available in the full relxill_nk package.
• In all models the relevant relativistic effects are calculated through a general relativistic ray-tracing code that can be applied to any well-behaved, stationary, axisymmetric, and asymptotically flat black hole spacetime.