130 citations · 476 across the 23 of their papers we have counts for
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Lense-Thirring precession of neutron-star accretion flows: Relativistic versus classical precession
Gabriel Török, Martin Urbanec, Monika Matuszková +5
The vertical (Lense-Thirring) precession of the innermost accretion flows has been discussed as a sensitive indicator of the rotational properties of neutron stars (NSs) and their…
Timing of accreting neutron stars with future X-ray instruments: towards new constraints on dense matter equation of state
V. Karas, K. Klimovicova, D. Lancova +7
The Enhanced X-ray Timing and Polarimetry (eXTP) mission is a space mission to be launched in the late 2020s that is currently in development led by China in international collabor…
Oscillations of Fluid Tori around Neutron Stars
Eva Šrámková, Monika Matuszková, Kateřina Klimovičová +7
We examine the influence of quadrupole moment of a slowly rotating neutron star (NS) on the oscillations of a fluid accretion disk (torus) orbiting a compact object the spacetime a…
Simple analytic formula relating the mass and spin of accreting compact objects to their rapid X-ray variability
Gabriel Török, Andrea Kotrlová, Monika Matuszková +4
Following the previous research on epicyclic oscillations of accretion disks around black holes (BHs) and neutron stars (NSs), a new model of high-frequency quasi-periodic oscillat…
Mass of the active galactic nucleus black hole XMMUJ134736.6+173403
Kateřina Goluchová, Gabriel Török, Eva Šrámková +3
A recent study of the X-ray source XMMUJ134736.6+173403 has revealed a strong quasi-periodic modulation of the X-ray flux. The observation of two quasiperiodic oscillations (QPOs)…
Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars. II. Forced resonances
Andrea Kotrlová, Eva Šrámková, Gabriel Török +2
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 Galacti…
Constraining models of twin peak quasi-periodic oscillations with realistic neutron star equations of state
Gabriel Török, Kateřina Goluchová, Martin Urbanec +8
Twin-peak quasi-periodic oscillations (QPOs) are observed in the X-ray power-density spectra of several accreting low-mass neutron star (NS) binaries. In our previous work we have…
Black hole spin inferred from 3:2 epicyclic resonance model of high-frequency quasi-periodic oscillations
E. Sramkova, G. Torok, A. Kotrlova +5
Estimations of black hole spin in the three Galactic microquasars GRS 1915+105, GRO J1655-40, and XTE J1550-564 have been carried out based on spectral and timing X-ray measurement…
Simulations of flux variability of oscillating accretion fluid tori around Kerr black holes
Pavel Bakala, Kateřina Goluchová, Eva Šrámková +4
High frequency quasi-periodic oscillations (HF QPOs) are observed in the X-ray power-density spectra (PDS) of several microquasars and low mass X-ray binaries. Many proposed QPO mo…
Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars
Andrea Kotrlova, Gabriel Torok, Eva Sramkova +1
We have previously applied several models of high-frequency quasi-periodic oscillations (HF QPOs) to estimate the spin of the central Kerr black hole in the three Galactic microqua…
Mass-angular-momentum relations implied by models of twin peak quasi-periodic oscillations
Gabriel Torok, Pavel Bakala, Eva Sramkova +3
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-sour…
Distinguishing between spot and torus models of high-frequency quasiperiodic oscillations
V. Karas, P. Bakala, G. Torok +8
In the context of high-frequency quasi-periodic oscillation (HF QPOs) we further explore the appearance of an observable signal generated by hot spots moving along quasi-elliptic t…
Power density spectra of modes of orbital motion in strongly curved spacetime: obtaining the observable signal
P. Bakala, G. Torok, V. Karas +8
High frequency quasi-periodic oscillations (HF QPOs) appear in the X-ray variability of several accreting low-mass binaries. In a series of works it was suggested that these QPOs m…
Non-geodesic orbital and epicyclic frequencies in vicinity of slowly rotating magnetized neutron stars
Pavel Bakala, Martin Urbanec, Eva Sramkova +2
We study non-geodesic corrections to the quasicircular motion of charged test particles in the field of magnetized slowly rotating neutron stars. The gravitational field is approxi…
Restrictions to neutron star properties based on twin-peak quasi-periodic oscillations
Gabriel Torok, Pavel Bakala, Eva Sramkova +3
We consider twin-peak quasi-periodic oscillations observed in the accreting low-mass neutron star binaries and explore restrictions to central compact object properties that are im…
Confronting the models of 3:2 QPOs with the evidence of near extreme Kerr black hole
Andrea Kotrlova, Gabriel Torok, Eva Sramkova +1
The black hole mass and spin estimates assuming various specific models of the 3:2 high frequency quasi-periodic oscillations (HF QPOs) have been carried out in Torok et al. (2005,…
Confronting the models of 3:2 quasiperiodic oscillations with the rapid spin of the microquasar GRS 1915+105
Gabriel Torok, Andrea Kotrlova, Eva Sramkova +1
Spectral fitting of the spin a in the microquasar GRS 1915+105 estimate values higher than a=0.98. However, there are certain doubts about this (nearly) extremal number. Confirming…
On mass-constraints implied by the relativistic precession model of twin-peak quasi-periodic oscillations in Circinus X-1
Gabriel Torok, Pavel Bakala, Eva Sramkova +2
Boutloukos et al. (2006) discovered twin-peak quasi-periodic oscillations (QPOs) in 11 observations of the peculiar Z-source Circinus X-1. Among several other conjunctions the auth…
Disc-oscillation resonance and neutron star QPOs: 3:2 epicyclic orbital model
Martin Urbanec, Gabriel Torok, Eva Sramkova +3
The high-frequency quasi-periodic oscillations (HF QPOs) that appear in the X-ray fluxes of low-mass X-ray binaries remain an unexplained phenomenon. Among other ideas, it has been…