X‐ray spectral states and high‐frequency QPOs in black holebinaries

Remillard, Ronald A.

doi:10.1002/asna.200510415

Cited by 34 publications

(56 citation statements)

References 19 publications

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“…BH X‐ray binary QPOs are not seen (or are very weak) in the high‐soft state that is typically associated with a thin disc dominated by MHD‐MRI turbulence (Wijnands & van der Klis 1999; Remillard 2005; Rubio‐Herrera & Lee 2005; Machida & Matsumoto 2008; Mondal, Basu & Chakrabarti 2009). The lack of QPOs in such a state is expected because non‐linear turbulence tends to reduce coherence.…”

Section: Fiducial Thick‐disc Modelmentioning

confidence: 99%

General relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around black holes

McKinney

Tchekhovskoy

Blandford

2012

Monthly Notices of the Royal Astronomical Society

870

1,074

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Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully 3D global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and thick (height H‐to‐cylindrical radius R ratio of |H/R| ∼ 0.2–1) accretion flows around BHs with various dimensionless spins (a/M, with BH mass M) and with initially toroidally dominated (φ‐directed) and poloidally dominated (R−z directed) magnetic fields. First, for toroidal field models and BHs with high enough |a/M|, coherent large‐scale (i.e. ≫H) dipolar poloidal magnetic flux patches emerge, thread the BH, and generate transient relativistic jets. Second, for poloidal field models, poloidal magnetic flux readily accretes through the disc from large radii and builds up to a natural saturation point near the BH. While models with |H/R| ∼ 1 and |a/M| ≤ 0.5 do not launch jets due to quenching by mass infall, for sufficiently high |a/M| or low |H/R| the polar magnetic field compresses the inflow into a geometrically thin highly non‐axisymmetric ‘magnetically choked accretion flow’ (MCAF) within which the standard linear magnetorotational instability is suppressed. The condition of a highly magnetized state over most of the horizon is optimal for the Blandford–Znajek mechanism which generates persistent relativistic jets with ≳100 per cent efficiency for |a/M| ≳ 0.9. A magnetic Rayleigh–Taylor and Kelvin–Helmholtz unstable magnetospheric interface forms between the compressed inflow and bulging jet magnetosphere, which drives a new jet–disc quasi‐periodic oscillation (JD‐QPO) mechanism. The high‐frequency QPO has spherical harmonic |m| = 1 mode period of τ∼ 70GM/c3 for a/M∼ 0.9 with coherence quality factors Q≳ 10. Overall, our models are qualitatively distinct from most prior MHD simulations (typically, |H/R| ≪ 1 and poloidal flux is limited by initial conditions), so they should prove useful for testing accretion‐jet theories and measuring a/M in systems such as SgrA* and M87.

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Section: Fiducial Thick‐disc Modelmentioning

confidence: 99%

General relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around black holes

McKinney

Tchekhovskoy

Blandford

2012

Monthly Notices of the Royal Astronomical Society

870

1,074

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“…There are three major methods: (i) continuum spectrum method (Hanawa 1989;Li et al 2005;McClintock et al 2011;McClintock et al 2014), (ii) line spectrum method (Kojima 1991;Laor 1991;Tanaka et al 1995;Duro et al 2011;Steiner et al 2011;Reynolds 2014), and (iii) quasi-periodic oscillation (QPO) method (Kato 2001;Strohmayer 2001;Rezzolla et al 2003;Remillard 2005;Kato et al 2008). …”

Section: Introductionmentioning

confidence: 99%

New method for black-hole spin measurement based on flux variation from an infalling gas ring

Moriyama

Mineshige

2015

Publications of the Astronomical Society of Japan

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We propose a new method for black hole spin measurement. In this method, we consider a gas blob or ring falling onto a black hole from the marginally stable orbit, keeping its initial orbital angular momentum. We calculate the gas motion and photon trajectories in the Kerr space-time and, assuming that the gas blob or ring emits monochromatic radiation, carefully examine how it is observed by a distant observer. The light curve of the orbiting gas blob is composed of many peaks because of periodic enhancement of the flux due to the gravitational lensing and beaming effects. Further, the intensity of each peak first gradually increases with time due to the focusing effect around the photon circular orbit and then rapidly decreases due to the gravitational redshift, as the gas blob approaches the event horizon. The light curve of the gas ring is equivalent to a superposition of those of the blobs with various initial orbital phases, and so it is continuous and with no peaks. The flux first gradually increases and then rapidly decays, as in the blob model. The flux variation timescale depends on the black hole spin and is independent from the inclination angle, while time averaged frequency shift have dependences of both effects. We can thus, in principle, determine spin and inclination angle from observations. The observational implications and future issues are briefly discussed.1

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“…In both these models the resonant phenomena could be irrelevant, as for the model of shock waves (Mondal & Chakrabarti 2006;Mondal et al 2009;Mondal & Choi 2013). (Remillard 2005), in extragalactic sources NGC 4051, MCG-6-30-15 (Lachowicz et al 2006), NGC 5408 X-1 (Strohmayer et al 2007), and the Galaxy centre Sgr A * show a variety of QPOs with frequency ratios differing from (or additional to) the 3:2 ratio.…”

Section: Multiple Resonances and Resonance Conditionsmentioning

confidence: 99%

“…Moreover, it is clear that strong gravity should also play an important role in the binary systems containing neutron (quark) stars. Quasiperiodic oscillations (QPOs) of X-ray brightness had been observed at low-(Hz) and high-(kHz) frequencies in many Galactic low mass X-ray binaries (LMXBs) containing neutron stars (see, e.g., van der Klis 2000Klis , 2006Barret et al 2005b;Belloni et al 2005Belloni et al , 2007bWang et al 2013) or black holes (see, e.g., Remillard 2005;Remillard & McClintock 2006). Some of the high-frequency (HF) QPOs are in the kHz range and often come in pairs of the upper and lower frequencies (ν U , ν L ) of twin peaks 1 in the Fourier power spectra.…”

Section: Introductionmentioning

confidence: 99%

Multi-resonance orbital model of high-frequency quasi-periodic oscillations: possible high-precision determination of black hole and neutron star spin

Stuchlík

Kotrlová

Török

2013

A&A

107

129

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Context. Using known frequencies of the twin-peak high-frequency quasiperiodic oscillations (HF QPOs) and known mass of the central black hole, the black-hole dimensionless spin a can be determined by assuming a concrete version of the resonance model. However, a wide range of observationally limited values of the black hole mass implies low precision of the spin estimates. Aims. We discuss the possibility of higher precision for the black hole spin a measurements in the framework of a multi-resonance model inspired by observations of more than two HF QPOs in the black hole systems, which are expected to occur at two (or more) different radii of the accretion disc. This framework is also applied in a modified form to the neutron star systems. Methods. We determine the spin and mass dependence of the twin-peak frequencies with a general rational ratio n:m, assuming a non-linear resonance of oscillations with the epicyclic and Keplerian frequencies or their combinations. In the multi-resonant model, the twin-peak resonances are combined properly to give the observed frequency set. For the black hole systems we focus on the special case of duplex frequencies, when the top, bottom, or mixed frequency is common at two different radii where the resonances occur giving triple frequency sets. Results. The sets of triple frequency ratios and the related spin a are given. The resonances are considered up to n = 5 since excitation of higher order resonances is improbable. The strong resonance model for "magic" values of the black hole spin means that two (or more) versions of resonance could occur at the same radius, allowing cooperative effects between the resonances. For neutron star systems we introduce a resonant switch model that assumes switching of oscillatory modes at resonant points. Conclusions. In the case of doubled twin-peak HF QPOs excited at two different radii with common top, bottom, or mixed frequency, the black hole spin a is given by the triple frequency ratio set. The spin is determined precisely, but not uniquely, because the same frequency set could correspond to more than one concrete spin a. The black hole mass is given by the magnitude of the observed frequencies. The resonant switch model puts relevant limits on the mass and spin of neutron stars, and we expect a strong increase in the fitting procedure precision when different twin oscillatory modes are applied to data in the vicinity of different resonant points. We expect the multi-resonance model to be applicable to data from the planned LOFT or similar X-ray satellite observatory.

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X‐ray spectral states and high‐frequency QPOs in black holebinaries

Cited by 34 publications

References 19 publications

General relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around black holes

General relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around black holes

New method for black-hole spin measurement based on flux variation from an infalling gas ring

Multi-resonance orbital model of high-frequency quasi-periodic oscillations: possible high-precision determination of black hole and neutron star spin

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