Details

Autor(en) / Beteiligte

• Blaes, Omer M
• Šrámková, Eva
• Abramowicz, Marek A
• Kluźniak, Włodek
• Torkelsson, Ulf

Titel

Epicyclic Oscillations of Fluid Bodies: Newtonian Nonslender Torus

Ist Teil von

• The Astrophysical journal, 2007-08, Vol.665 (1), p.642-653

Ort / Verlag

Chicago, IL: IOP Publishing

Erscheinungsjahr

2007

Link zum Volltext

Quelle

Elektronische Zeitschriftenbibliothek - Frei zugängliche E-Journals

Beschreibungen/Notizen

• We study epicyclic oscillations of fluid tori around black holes (in the Paczynski-Wiita potential) and derive exact analytic expressions for their radial and vertical eigenfrequendes [unk] and v2 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 v2/ [unk] = 3/2, which is important for the theory of high-frequency quasi-periodic oscillations (QPOs), occurs when the fluid tori epicyclic frequencies [unk] and v2 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.