Oscillations of the Eddington capture sphere
Artikel i vetenskaplig tidskrift, 2012

We present a toy model of mildly super-Eddington, optically thin accretion onto a compact star in the Schwarzschild metric, which predicts periodic variations of luminosity when matter is supplied to the system at a constant accretion rate. These are related to the periodic appearance and disappearance of the Eddington capture sphere. In the model the frequency is found to vary inversely with the luminosity. If the input accretion rate varies (strictly) periodically, the luminosity variation is quasi-periodic, and the quality factor is inversely proportional to the relative amplitude of mass accretion fluctuations, with its largest value Q ≈ 1/(10 |δṀ/Ṁ|) attained in oscillations at about 1 to 2 kHz frequencies for a 2  M⊙ star.

Författare

Maciej Wielgus

Adam Stahl

Göteborgs universitet

Marek A Abramowicz

Göteborgs universitet

Wlodek Kluźniak

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 545 artikel nr A123-

Ämneskategorier

Astronomi, astrofysik och kosmologi

Fundament

Grundläggande vetenskaper

DOI

10.1051/0004-6361/201220228