Bremen 2017 – scientific programme

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GR: Fachverband Gravitation und Relativitätstheorie

GR 1: Schwarze Löcher 1

GR 1.3: Talk

Monday, March 13, 2017, 09:30–09:50, SFG 0140

Shadow of a Kerr black hole in a plasma — •Volker Perlick¹ and Oleg Yu. Tsupko² — ¹ZARM, Universität Bremen, 28359 Bremen — ²Space Research Institute of the Russian Academy of Sciences, Profsoyuznaya 84/32, Moscow 117997, Russia

We consider light propagation in a plasma around a Kerr black hole. The plasma is assumed to be pressureless (“cold”) and non-magnetised. We find the necessary and sufficient condition on the plasma electron density that guarantees separability of the Hamilton-Jacobi equation for the light rays (i.e., that guarantees existence of a Carter constant). For all cases where this separability condition is satisfied, we give an analytical formula for the boundary curve of the shadow of the Kerr black hole. The general results will be illustrated with several examples of specific plasma electron densities. The perspectives of actually observing the influence of the plasma on the shadow will be discussed.