J 2012

MASS-ANGULAR-MOMENTUM RELATIONS IMPLIED BY MODELS OF TWIN PEAK QUASI-PERIODIC OSCILLATIONS

TÖRÖK, Gabriel, Pavel BAKALA, Eva ŠRÁMKOVÁ, Zdeněk STUCHLÍK, Martin URBANEC et. al.

Basic information

Original name

MASS-ANGULAR-MOMENTUM RELATIONS IMPLIED BY MODELS OF TWIN PEAK QUASI-PERIODIC OSCILLATIONS

Authors

TÖRÖK, Gabriel, Pavel BAKALA, Eva ŠRÁMKOVÁ, Zdeněk STUCHLÍK, Martin URBANEC and Kateřina GOLUCHOVÁ

Edition

Astrophysical Journal, BRISTOL, IOP PUBLISHING LTD, 2012, 0004-637X

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Confidentiality degree

není předmětem státního či obchodního tajemství

Organization unit

Institute of physics in Opava

DOI

http://dx.doi.org/10.1088/0004-637X/760/2/138

UT WoS

000311217000042

Keywords in English

stars: neutron; X-rays: binaries

Tags

clanek, CZ1072300200071, GACR202090772, GACR20912P740, LC06014, MSM4781305903, SGS12010, SGS22010, Torokcentrum

Tags

International impact, Reviewed
Změněno: 27/4/2021 09:45, Jan Vlha

Abstract

V originále

Twin peak quasi-periodic oscillations (QPOs) appear in the X-ray power-density spectra of several accreting low-mass neutron star (NS) binaries. Observations of the peculiar Z-source Circinus X-1 display unusually low QPO frequencies. Using these observations, we have previously considered the relativistic precession (RP) twin peak QPO model to estimate the mass of the central NS in Circinus X-1. We have shown that such an estimate results in a specific mass-angular-momentum (M-j) relation rather than a single preferred combination of M and j. Here we confront our previous results with another binary, the atoll source 4U 1636-53 that displays the twin peak QPOs at very high frequencies, and extend the consideration to various twin peak QPO models. In analogy to the RP model, we find that these imply their own specific M-j relations. We explore these relations for both sources and note differences in the chi(2) behavior that represent a dichotomy between high-and low-frequency sources. Based on the RP model, we demonstrate that this dichotomy is related to a strong variability of the model predictive power across the frequency plane. This variability naturally comes from the radial dependence of characteristic frequencies of orbital motion. As a consequence, the restrictions on the models resulting from observations of low-frequency sources are weaker than those in the case of high-frequency sources. Finally we also discuss the need for a correction to the RP model and consider the removing of M-j degeneracies, based on the twin peak QPO-independent angular momentum estimates.
Displayed: 25/12/2024 23:18