J 2017

Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars II. Forced resonances

KOTRLOVÁ, Andrea, Eva ŠRÁMKOVÁ, Gabriel TÖRÖK, Zdeněk STUCHLÍK, Kateřina GOLUCHOVÁ et. al.

Basic information

Original name

Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars II. Forced resonances

Authors

KOTRLOVÁ, Andrea (203 Czech Republic, guarantor, belonging to the institution), Eva ŠRÁMKOVÁ (203 Czech Republic, belonging to the institution), Gabriel TÖRÖK (203 Czech Republic, belonging to the institution), Zdeněk STUCHLÍK (203 Czech Republic, belonging to the institution) and Kateřina GOLUCHOVÁ (203 Czech Republic, belonging to the institution)

Edition

Astronomy & Astrophysics, 2017, 0004-6361

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

France

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/47813059:19240/17:A0000007

Organization unit

Faculty of Philosophy and Science in Opava

UT WoS

000415265200006

Keywords in English

X-rays: binaries; black hole physics; accretion; accretion disks

Tags

International impact, Reviewed

Links

GA17-16287S, research and development project. GB14-37086G, research and development project. LTI17018, research and development project.
Změněno: 9/4/2018 04:12, RNDr. Jan Hladík, Ph.D.

Abstract

V originále

In our previous work ( Paper I) we applied several models of high-frequency quasi-periodic oscillations (HF QPOs) to estimate the spin of the central compact object in three Galactic microquasars assuming the possibility that the central compact body is a superspinning object ( or a naked singularity) with external spacetime described by Kerr geometry with a dimensionless spin parameter a equal to cJ/GM^(2) > 1. Here we extend our consideration, and in a consistent way investigate implications of a set of ten resonance models so far discussed only in the context of a < 1. The same physical arguments as in Paper I are applied to these models, i.e. only a small deviation of the spin estimate from a = 1, a greater than or similar to 1, is assumed for a favoured model. For five of these models that involve Keplerian and radial epicyclic oscillations we find the existence of a unique specific QPO excitation radius. Consequently, there is a simple behaviour of dimensionless frequency M x nu_(U)(a) represented by a single continuous function having solely one maximum close to a greater than or similar to 1. Only one of these models is compatible with the expectation of a greater than or similar to 1. The other five models that involve the radial and vertical epicyclic oscillations imply the existence of multiple resonant radii. This signifies a more complicated behaviour of M x nu_(U)(a) that cannot be represented by single functions. Each of these five models is compatible with the expectation of a greater than or similar to 1.