A possible 3:2 orbital epicyclic resonance in QPO frequencies of Sgr A*

¹ Nordita, Blegdamsvej 17, 2100 Copenhagen, Denmark
² Department of Astrophysics, Göteborg University & Theoretical Physics, Chalmers University, 412-96 Göteborg, Sweden
³ Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo Nám. 13, 746 01 Opava, Czech Republic e-mail: terek@volny.cz

Received: 17 December 2004
Accepted: 7 May 2005

Abstract

A recent measurement of double peak QPOs frequencies in Sgr A* is consistent with the 3:2 ratio. The same ratio is firmly established by previous observations in all double peaked kHz QPOs in microquasars and theoretically explained by orbital epicyclic resonances excited in nearly Keplerian accretion flow in a black hole's strong gravity. If confirmed, the 3:2 ratio of double peak QPOs in Sgr A* will be of a fundamental importance for the black hole accretion theory, by providing another clear argument that the accretion disk oscillations are indeed governed by non-linear, strong-gravity physics.