English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

XTE J1650-500 is a Galactic black-hole binary system for which at least onehigh-frequency QPO at 250Hz was reported. Moreover there are indications thatthe system harbours a near-extreme Kerr black-hole with the spin near 0.998 andmass M<7.3M_sun. Recently it was discovered that the orbital 3-velocity ofKeplerian (geodesical) discs orbiting Kerr black holes with the spin a>0.9953,being analyzed in the locally non-rotating frames, reveals a hump near themarginally stable orbit. Further it was suggested that the hump could excitethe epicyclic motion of particles near the ISCO with frequencies typical forhigh-frequency QPOs. Characteristic frequency of the hump-induced oscillationswas defined as the maximal positive rate of change of the LNRF-related orbitalvelocity with the proper radial distance. If the characteristic "humpyfrequency" and the radial epicyclic frequency are commensurable, strongresonant phenomena are expected. For the Kerr black hole with the spin a=0.9982the "humpy frequency" and the radial epicyclic frequency are in ratio 1:3.Identifying the radial epicyclic frequency with the observed 250Hz QPO, we getthe mass of the black hole in XTE J1650-500 near 5.1M_sun.

Mass estimate of the XTE J1650-500 black hole from the Extended Orbital Resonance Model for high-frequency QPOs