J 2022

Simple Analytic Formula Relating the Mass and Spin of Accreting Compact Objects to Their Rapid X-Ray Variability

TÖRÖK, Gabriel, Andrea KOTRLOVÁ, Monika MATUSZKOVÁ, Kateřina KLIMOVIČOVÁ, Debora LANČOVÁ et. al.

Basic information

Original name

Simple Analytic Formula Relating the Mass and Spin of Accreting Compact Objects to Their Rapid X-Ray Variability

Authors

TÖRÖK, Gabriel (203 Czech Republic, belonging to the institution), Andrea KOTRLOVÁ (203 Czech Republic, belonging to the institution), Monika MATUSZKOVÁ (203 Czech Republic, belonging to the institution), Kateřina KLIMOVIČOVÁ (203 Czech Republic, belonging to the institution), Debora LANČOVÁ (203 Czech Republic, belonging to the institution), Gabriela URBANCOVÁ (203 Czech Republic, belonging to the institution) and Eva ŠRÁMKOVÁ (203 Czech Republic, belonging to the institution)

Edition

Astrophysical Journal, GB - Spojené království Velké Británie a, 2022, 0004-637X

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

URL

RIV identification code

RIV/47813059:19630/22:A0000181

Organization unit

Institute of physics in Opava

DOI

http://dx.doi.org/10.3847/1538-4357/ac5ab6

UT WoS

000780481600001

Keywords in English

quasi-periodic oscillations;rotating relativistic stars;armed corrugation waves;black holes binaries;twin KHZ QPOS;neutron star;spectral properties;epicyclic oscillations;frequency correlations;nonlinear resonance

Tags

, RIV23, SGF-1-2020, SGS-12-2019, SGS-13-2019

Tags

International impact, Reviewed

Links

EF18_054/0014696, research and development project. GX21-06825X, research and development project. LTC18058, research and development project.
Změněno: 8/3/2023 14:17, Mgr. Pavlína Jalůvková

Abstract

V originále

Following the previous research on epicyclic oscillations of accretion disks around black holes (BHs) and neutron stars (NSs), a new model of high-frequency quasiperiodic oscillations (QPOs) has been proposed, so-called cusp torus (CT) model, which deals with oscillations of fluid in marginally overflowing accretion tori (i.e., tori terminated by cusps). According to preliminary investigations, the model provides better fits of the NS QPO data compared to the relativistic precession (RP) model. It also implies a significantly higher upper limit on the Galactic microquasar BH spins. A short analytic formula has been noticed to well reproduce the model's predictions on the QPO frequencies in Schwarzschild spacetimes. Here we derive an extended version of this formula that applies to rotating compact objects. We start with the consideration of Kerr spacetimes and derive a formula that is not restricted to a particular specific angular momentum distribution of the inner accretion flow, such as a Keplerian or constant one. Finally, we consider Hartle-Thorne spacetimes and include corrections implied by the NS oblateness. For a particular choice of a single parameter, our relation provides frequencies predicted by the CT model. For another value, it provides frequencies predicted by the RP model. We conclude that the formula is well applicable to rotating oblate NSs and both models. We briefly illustrate the application of our simple formula on several NS sources and confirm the expectation that the CT model is compatible with realistic values of the NS mass and provides better fits of data than the RP model.
Displayed: 1/11/2024 00:28