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A possible mechanism for QPOs modulation in neutron star sources
Author(s) -
Horák J.
Publication year - 2005
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.200510425
Subject(s) - physics , neutron star , accretion (finance) , astrophysics , luminosity , boundary layer , intermediate polar , circular orbit , stars , accretion disc , astronomy , mechanics , white dwarf , galaxy
It was pointed out by Paczyński (1987) that the X‐ray luminosity of accreting neutron stars is very sensitive to the physical properties of the accretion flow close to the innermost stable circular orbit. The X‐ray radiation is dominated by that emitted in the boundary layer, where accreted matter hits a star surface. The X‐ray luminosity of the boundary layer is proportional to the local accretion rate. In this note, we estimate a local accretion rate variations from the disk that undergoes non‐stationary axisymmetric perturbations. The perturbations are given by the poloidal‐velocity potential.We obtain a simple formula describing the modulation of the accretion rate for the particular case of global vertical disk oscillations that have been recently studied by Abramowicz et al. (2005). (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)