Public Release of RELXILL_NK: A Relativistic Reflection Model for Testing Einstein’s Gravity
Аннотация
Abstract 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 (BH) 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 BH spacetime. We show that the numerical error introduced by using a ray-tracing code is not significant compared with the observational error present in current X-ray reflection spectrum observations. In addition, we present the reflection spectrum for the Johannsen metric as calculated by relxill _ nk .