To the top

Page Manager: Webmaster
Last update: 9/11/2012 3:13 PM

Tell a friend about this page
Print version

Epicyclic Oscillations of… - University of Gothenburg, Sweden Till startsida
Sitemap
To content Read more about how we use cookies on gu.se

Epicyclic Oscillations of Fluid Bodies: Newtonian Nonslender Torus

Journal article
Authors Omer Blaes
Eva Šrámková
Marek A Abramowicz
Włodek Kluźniak
Ulf Torkelsson
Published in Astrophysical Journal
Volume 665
Issue 1
Pages 642-653
ISSN 0004-637X
Publication year 2007
Published at Department of Physics (GU)
Pages 642-653
Language en
Links www.journals.uchicago.edu/ApJ/journ...
Keywords Accretion, Accretion Disks, Black Hole Physics, Hydrodynamics, X-Rays: Binaries
Subject categories High energy astrophysics, Theory of relativity, gravitation

Abstract

We study epicyclic oscillations of fluid tori around black holes (in the Paczyński-Wiita potential) and derive exact analytic expressions for their radial and vertical eigenfrequencies νr and νz to second-order accuracy in the width of the torus. We prove that pressure effects make the eigenfrequencies smaller than those for free particles. However, the particular ratio νz/νr=3/2, which is important for the theory of high-frequency quasi-periodic oscillations (QPOs), occurs when the fluid tori epicyclic frequencies νr and νz are about 15% higher than the ones corresponding to free particles. Our results therefore suggest that previous estimates of black hole spins from QPOs have produced values that are too high.

Page Manager: Webmaster|Last update: 9/11/2012
Share:

The University of Gothenburg uses cookies to provide you with the best possible user experience. By continuing on this website, you approve of our use of cookies.  What are cookies?