UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Kilohertz QPOs in low-mass X-ray binaries as oscillation modes of tori around neutron stars - I

de Avellar, MGB; Porth, O; Younsi, Z; Rezzolla, L; (2018) Kilohertz QPOs in low-mass X-ray binaries as oscillation modes of tori around neutron stars - I. Monthly Notices of the Royal Astronomical Society , 474 (3) pp. 3967-3975. 10.1093/mnras/stx3071. Green open access

[thumbnail of stx3071.pdf]
Preview
Text
stx3071.pdf - Published Version

Download (864kB) | Preview

Abstract

There have been many efforts to explain the dynamical mechanisms behind the phenomenology of quasi-periodic oscillations (QPOs) seen in the X-ray light curves of low-mass X-ray binaries. Up to now, none of the models can successfully explain all the frequencies observed in the power spectral density of the light curves. After performing several general-relativistic hydrodynamic simulations of non-self-gravitating axisymmetric thick tori with constant specific angular momentum oscillating around a neutron star such as the one associated with the low-mass X-ray binary 4U 1636 − 53, we find that the oscillation modes give rise to QPOs similar to those seen in the observational data. In particular, when matching pairs of kilohertz QPOs from the numerical simulations with those observed, certain combinations reproduce well the observations, provided we take a mass for the neutron star that is smaller than what is generally assumed. At the same time, we find that tori with constant specific angular momentum cannot match the entire range of frequencies observed for 4U 1636−53 due to physical constraints set on their size. Finally, we show that our results are consistent with the observed shifts in QPO frequency that could accompany state transitions of the accretion disc.

Type: Article
Title: Kilohertz QPOs in low-mass X-ray binaries as oscillation modes of tori around neutron stars - I
Open access status: An open access version is available from UCL Discovery
DOI: 10.1093/mnras/stx3071
Publisher version: https://doi.org/10.1093/mnras/stx3071
Language: English
Additional information: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions.
Keywords: accretion, accretion discs, stars: oscillations, X-rays: binaries
UCL classification: UCL
UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > UCL BEAMS
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences
UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics
URI: https://discovery.ucl.ac.uk/id/eprint/10073621
Downloads since deposit
Loading...
0Downloads
Download activity - last month
Loading...
Download activity - last 12 months
Loading...
Downloads by country - last 12 months
1.United States
7
2.China
4
3.Germany
1
4.Switzerland
1
5.France
1
6.South Africa
1
7.Russian Federation
1

Archive Staff Only

View Item View Item