Test of the string loop oscillation model using kHz quasiperiodic oscillations in a neutron star binary

Stuchlík, Zdeněk; Kološ, Martin

doi:10.1007/s10714-015-1863-y

Cited by 6 publications

(9 citation statements)

References 74 publications

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“…It has been shown that the exact numerical models and external Hartle-Thorne geometry give very similar spacetime structure for models with dimensionless spin a = J/M 2 = 0.4 and can be thus applied to almost all of the observed neutron stars [129][130][131]. The external Hartle-Thorne geometry exactly corresponds to the Kerr geometry, if the dimensionless quadrupole moment q ≡ QM/J 2 = 1, and they can be very close if q ≤ 2 [131,132]. The neutron star with q ≤ 2 are very massive and compact stars, near the maximum mass allowed by considered equation of state.…”

Section: Ultra-high Energy Cosmic Rays As Products Of Mpp In the Extrmentioning

confidence: 94%

Influence of Cosmic Repulsion and Magnetic Fields on Accretion Disks Rotating around Kerr Black Holes

et al. 2020

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We present a review of the influence of cosmic repulsion and external magnetic fields on accretion disks rotating around rotating black holes and on jets associated with these rotating configurations. We consider both geometrically thin and thick disks. We show that the vacuum energy represented by the relic cosmological constant strongly limits extension of the accretion disks that is for supermassive black holes comparable to extension of largest galaxies, and supports collimation of jets at large distances from the black hole. We further demonstrate that an external magnetic field crucially influences the fate of ionized Keplerian disks causing creation of winds and jets, enabling simultaneously acceleration of ultra-high energy particles with energy up to 10 21 eV around supermassive black holes with M ∼ 10 10 M ⊙ surrounded by sufficiently strong magnetic field with B ∼ 10 4 G. We also show that the external magnetic fields enable existence of “levitating” off-equatorial clouds or tori, along with the standard equatorial toroidal structures, if these carry a non-vanishing, appropriately distributed electric charge.

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Section: Ultra-high Energy Cosmic Rays As Products Of Mpp In the Extrmentioning

confidence: 94%

Influence of Cosmic Repulsion and Magnetic Fields on Accretion Disks Rotating around Kerr Black Holes

et al. 2020

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“…This property of the radial profiles of the radial and vertical frequencies of the string loop oscillations introduces an unambiquity into the fitting of the HF QPOs even in the black hole spacetimes and makes the estimates of the black hole mass more complex. However, it can be conveniently applied to explain the special frequency set of HF QPOs observed recently in the source XTE J1701-407 that is a LMXB system containing a neutron star (Pawar et al 2013;Stuchlík & Kološ 2015). The radial profiles of the string loop oscillations are demonstrated in Figure 1 for value of the Kerr spin parameter a = 0.7 and in the Schwarzschild spacetime (a = 0), where the situation is degenerate, since both the frequencies are independent of the stringy parameter ω.…”

Section: Frequency Of the String-loop Radial And Vertical Oscillatory...mentioning

confidence: 99%

“…In the case of the string loop oscillation model the additional nodal frequency model is not relevant, and is not applied for the mass estimates. For possibility to obtain a low frequency string loop oscillations see (Stuchlík & Kološ 2015)…”

Section: Fitting the Twin Hf Qpo Frequencies Observed In M82 X-1 By O...mentioning

confidence: 99%

“…Their oscillations are thus governed not only by the black hole gravitational field, but also the string loop parameters determining the interplay of the string loop angular momentum and (magnetic) tension are relevant (Stuchlík & Kološ 2012b;. Contrary to the geodesic models, the string loop oscillation model can explain the 3 : 2 twin HF QPOs in all the three microquasars ), moreover, it can be applied also to neutron star systems (Stuchlík & Kološ 2015). It is thus interesting to test its predictions for the intermediate black hole system.…”

Section: Introductionmentioning

confidence: 99%

“…For comparison, we have used also the recently introduced (non-geodesic) string loop oscillation model that can be well applied to the frequencies of the twin HF QPOs observed in Galactic microquasars , or some neutron star LMXBs (Stuchlík & Kološ 2015).…”

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Mass of intermediate black hole in the source M82 X-1 restricted by models of twin high-frequency quasi-periodic oscillations

Stuchlík

Kološ

2015

Monthly Notices of the Royal Astronomical Society

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We apply the relativistic precession model with its variants and the resonance epicyclic model with its variants, based on the frequencies of the geodesic epicyclic motion in the field of a Kerr black hole, to put limits on the mass of the black hole in the ultraluminous X-ray source M82 X-1 demonstrating twin high-frequency quasiperiodic oscillations (HF QPOs) with the frequency ratio near 3:2. The mass limits implied by the geodesic HF QPO models are compared to those obtained due to the model of string loop oscillations around a stable equilibrium position. Assuming whole the range of the black hole dimensionless spin, 0 < a < 1, the restrictions on the black hole mass related to the twin HF QPOs are widely extended and strongly model dependent, nevertheless, they give the lower limit M M82X−1 > 130 M ⊙ confirming existence of an intermediate black hole in the M82 X-1 source. The upper limit given by one of the variants of the geodesic twin HF QPO models goes up to M M82X−1 < 1500 M ⊙ . The range 37 mHz-210 mHz of the low frequency QPOs observed in the M82 X-1 source introduces additional restrictive limits on the black hole mass, if we model the low frequency QPOs by nodal precession of the epicyclic motion. The nodal precession model restrictions combined with those implied by the geodesic models of the twin HF QPOs give allowed ranges of the M82 X-1 black hole parameters, namely 140 M ⊙ < M M82X−1 < 660 M ⊙ for the mass parameter, and 0.05 < a M82X−1 < 0.6 for the spin parameter.

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Application of the relativistic precession model to the accreting milisecond X‐ray pulsar IGR J17511–3057

Stefanov¹

2016

Astron Nachr

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The observation of a pair of simultaneous twin kHz QPOs in the power density spectrum of a neutron star or a black hole allows its mass-angular-momentum relation to be constrained. Situations in which the observed simultaneous pairs are more than one allow the different models of the kHz QPOs to be falsified. Discrepancy between the estimates coming from the different pairs would call the used model into question. In the current paper the relativistic precession model is applied to the twin kHz QPOs that appear in the light curves of three groups of observations of the accreting millisecond X-ray pulsar IGR J17511-3057. It was found that the predictions of one of the groups are practically in conflict with the other two. Another interesting result is that the region in which the kHz QPOs have been born is rather broad and extends quite far from the ISCO.

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Test of the string loop oscillation model using kHz quasiperiodic oscillations in a neutron star binary

Cited by 6 publications

References 74 publications

Influence of Cosmic Repulsion and Magnetic Fields on Accretion Disks Rotating around Kerr Black Holes

Influence of Cosmic Repulsion and Magnetic Fields on Accretion Disks Rotating around Kerr Black Holes

Mass of intermediate black hole in the source M82 X-1 restricted by models of twin high-frequency quasi-periodic oscillations

Application of the relativistic precession model to the accreting milisecond X‐ray pulsar IGR J17511–3057

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