Models of high-frequency quasi-periodic oscillations and black hole spin estimates in Galactic microquasars

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19630%2F20%3AA0000010" target="_blank" >RIV/47813059:19630/20:A0000010 - isvavai.cz</a>

Result on the web

<a href="https://www.aanda.org/articles/aa/abs/2020/11/aa37097-19/aa37097-19.html" target="_blank" >https://www.aanda.org/articles/aa/abs/2020/11/aa37097-19/aa37097-19.html</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201937097" target="_blank" >10.1051/0004-6361/201937097</a>

Result language

angličtina

Original language name

Models of high-frequency quasi-periodic oscillations and black hole spin estimates in Galactic microquasars

Original language description

We explore the influence of nongeodesic pressure forces present in an accretion disc on the frequencies of its axisymmetric and nonaxisymmetric epicyclic oscillation modes. We discuss its implications for models of high-frequency quasi-periodic oscillations (QPOs), which have been observed in the X-ray flux of accreting black holes (BHs) in the three Galactic microquasars, GRS 1915+105, GRO J1655-40, and XTE J1550-564. We focus on previously considered QPO models that deal with low-azimuthal-number epicyclic modes, |m| &lt;= 2, and outline the consequences for the estimations of BH spin, a is an element of [0, 1]. For four out of six examined models, we find only small, rather insignificant changes compared to the geodesic case. For the other two models, on the other hand, there is a significant increase of the estimated upper limit on the spin. Regarding the falsifiability of the QPO models, we find that one particular model from the examined set is incompatible with the data. If the spectral spin estimates for the microquasars that point to a&gt; 0.65 were fully confirmed, two more QPO models would be ruled out. Moreover, if two very different values of the spin, such as a approximate to 0.65 in GRO J1655-40 and a approximate to 1 in GRS 1915+105, were confirmed, all the models except one would remain unsupported by our results. Finally, we discuss the implications for a model that was recently proposed in the context of neutron star (NS) QPOs as a disc-oscillation-based modification of the relativistic precession model. This model provides overall better fits of the NS data and predicts more realistic values of the NS mass compared to the relativistic precession model. We conclude that it also implies a significantly higher upper limit on the microquasar's BH spin (a similar to 0.75 vs. a similar to 0.55).

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

643

Issue of the periodical within the volume

October

Country of publishing house

FR - FRANCE

Number of pages

9

Pages from-to

„A31-1“-„A31-9“

UT code for WoS article

000588072000002

EID of the result in the Scopus database

2-s2.0-85095110376