arXiv subjects

Chang-Yin Huang

Publications and source records attributed to Chang-Yin Huang.

12 recordsLinked to original sources

arXiv2025

Revisiting the infrared/X-ray correlation of GX 339-4 based on a jet model

The infrared (IR)/X-ray correlation of GX 339$-$4 is investigated based on a jet model with a modification by linking the magnetic field at the jet base to the accretion rate of the inner accretion flow though the the equilibrium between magnetic pressure at horizon and the ram pressure of the accretion flow. The IR flux is attributed to the synchrotron radiation of the jet, and the X-ray flux is attributed to the advective dominated accretion flow (ADAF), synchrotron radiation of the jet and synchrotron self-Compton scattering (SSC) of the jet, respectively. We find that the observed IR/X-ray correlation with a break is well reproduced with the variation of the accretion rate if the X-ray flux originates from SSC of the jet. Either a conical ballistic jet with the magnetic field parallel to the jet axis or a conical adiabatic jet with an isotropic field can account for the correlation. The power-law index of the energy distribution of electrons $p\sim3$, the minimum Lorentz factor of the electrons $γ_{\rm min}\sim60$, the magnetic field $B_0\sim10^5\ {\rm G}$ and the jet radius $R_0\sim10^{10}\ {\rm cm}$ at the jet base are required for both the ballistic jet and the adiabatic jet. This study helps us clarify the complex interaction between the accretion and jet in GX 339$-$4, as well as the properties and geometric structure of the jet, laying the groundwork for exploring similar astrophysical systems.

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arXiv2016

A model for 3:2 HFQPO pairs in black hole binaries based on cosmic battery

A model for 3:2 high-frequency quasi-periodic oscillations (HFQPOs) with 3:2 pairs observed in four black hole X-ray binaries (BHXBs) is proposed by invoking the epicyclic resonances with the magnetic connection (MC) between a spinning black hole (BH) with a relativistic accretion disc. It turns out that the MC can be worked out due to Poynting-Robertson cosmic battery (PRCB), and the 3:2 HFQPO pairs associated with the steep power-law states can be fitted in this model. Furthermore, the severe damping problem in the epicyclic resonance model can be overcome by transferring energy from the BH to the inner disc via the MC process for emitting X-rays with sufficient amplitude and coherence to produce the HFQPOs. In addition, we discuss the important role of the magnetic field in state transition of BHXBs.

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arXiv2015

A magnetic model for low/hard state of black hole binaries

A magnetic model for low/hard state (LHS) of black hole X-ray binaries (BHXBs),H1743-322 and GX 339-4, is proposed based on the transportation of magnetic field from a companion into an accretion disk around a black hole (BH). This model consists of a truncated thin disk with an inner advection-dominated accretion flow (ADAF). The spectral profiles of the sources are fitted in agreement with the data observed at four different dates corresponding to the rising phase of the LHS. In addition, the association of the LHS with quasi-steady jet is modelled based on transportation of magnetic field, where the Blandford-Znajek (BZ) and Blandford-Payne (BP) processes are invoked to drive the jets from BH and inner ADAF. It turns out that the steep radio/X-ray correlations observed in H1743-322 and GX 339-4 can be interpreted based on our model.

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arXiv2014

A disk-corona model for low/hard state of black hole X-ray binaries

A disk-corona model for fitting low/hard (LH) state of associated steady jet of black hole X-ray binaries (BHXBs) is proposed based on the large-scale magnetic field configuration of the coexistence of the Blandford-Znajek (BZ) and Blandford-Payne (BP) processes,where the magnetic field configuration for the BP process is determined by the requirement of energy conversion from Poynting energy flux into kinetic energy flux in the jet. It is found that corona current is crucial to guarantee the consistency of the jet launching from accretion disk. The relative importance of the BZ to BP processes in powering jets from black hole accretion disk is discussed, and the LH state of several BHXBs is fitted based on our model.In addition, we suggest that magnetic field configuration could be regarded as the second parameter for governing the state transition of BHXBs.

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arXiv2014

Quasi-Periodic Variations in X-ray Emission and Long-Term Radio Observations: Evidence for a Two-Component Jet in Sw J1644+57

The continued observations of Sw J1644+57 in X-ray and radio bands accumulated a rich data set to study the relativistic jet launched in this tidal disruption event. The X-ray light curve of Sw J1644+57 from 5-30 days presents two kinds of quasi-periodic variations: a 200 second quasi-periodic oscillation (QPO) and a 2.7-day quasi-periodic variation. The latter has been interpreted by a precessing jet launched near the Bardeen-Petterson radius of a warped disk. Here we suggest that the $\sim$ 200s QPO could be associated with a second, narrower jet sweeping the observer line-of-sight periodically, which is launched from a spinning black hole in the misaligned direction with respect to the black hole's angular momentum. In addition, we show that this two-component jet model can interpret the radio light curve of the event, especially the re-brightening feature starting $\sim 100$ days after the trigger. From the data we infer that inner jet may have a Lorentz factor of $Γ_{\rm j} \sim 5.5$ and a kinetic energy of $E_{\rm k,iso} \sim 3.0 \times 10^{52} {\rm erg}$, while the outer jet may have a Lorentz factor of $Γ_{\rm j} \sim 2.5$ and a kinetic energy of $E_{\rm k,iso} \sim 3.0 \times 10^{53} {\rm erg}$.

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arXiv2014

Modelling the `outliers' track of the radio--X-ray correlation in X-ray binaries based on disc-corona model

The universal radio--X-ray correlation (F_R \propto F_X^{b}, b~0.5-0.7) has been found for a sample of black-hole X-ray binaries (BHBs) in their low/hard states, which can roughly be explained by the coupled model of jet and radiatively inefficient advection dominated accretion flow. However, more and more `outliers' were found in last few years, which evidently deviate from the universal radio-X-ray correlation and usually show a much steeper correlation with an index of ~1.4. Based on simple physical assumptions, the radiatively efficient accretion flows are speculated to exist in these `outliers'. In this work, we test this issue by modelling the `outliers' track based on the radiatively efficient disc-corona model and the hybrid jet model. We find that our model predicts a steeper radio--X-ray correlation with slopes >~1.2 for the typical viscosity parameter of α~0.05-0.2. In particular, the slope is ~1.4 for the case of α~0.1, which is consistent with the observational results of H1743-322 very well. Our results suggest that the `outliers' track may be regulated by the disc-corona model.

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arXiv2013

A magnetic reconnection model for quasi-periodic oscillations in black hole systems

The quasi-periodic oscillations (QPOs) in black hole (BH) systems of different scales are interpreted based on the magnetic reconnection of the large-scale magnetic fields generated by the toroidal electric currents flowing in the inner region of accretion disk, where the current density is assumed to be proportional to the mass density of the accreting plasma. The magnetic connection (MC) is taken into account in resolving the dynamic equations of the accretion disk, in which the MC between the inner and outer disk regions, the MC between the plunging region and the disk, and the MC between the BH horizon and the disk are involved. It turns out that the single QPO frequency of several BH systems of different scales can be fitted by invoking the magnetic reconnection due to the MC between the inner and outer regions of the disk, where the BH binaries XTE J1859+226, XTE J1650-500 and GRS 1915+105 and the massive BHs in NGC 5408 X-1 and RE J1034+396 are included. In addition, the X-ray spectra corresponding to the QPOs are fitted for these sources based on the typical disk-corona model.

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arXiv2012

A Model of Low-Frequency Quasi-Periodic Oscillations in Black Hole X-Ray Binaries

A model of low-frequency quasi-periodic oscillations (LFQPOs) of black hole X-ray binaries (BHXBs) is proposed based on the perturbed magnetohydrodynamic (MHD) equations of accretion disk. It turns out that the LFQPOs frequencies of some BHXBs can be fitted by the frequencies of the toroidal Alfvén wave oscillation corresponding to the maximal radiation flux. In addition, the positive correlation of the LFQPO frequencies with the radiation flux from accretion disk is well interpreted.

astro-ph.HE↗

arXiv2009

A resonance model with magnetic connection for 3:2 HFQPO pairs in black hole binaries

We apply epicyclic resonances to the magnetic connection (MC) of a black hole (BH) with a relativistic accretion disc, interpreting the high frequency quasi-periodic oscillations (HFQPOs) with 3:2 pairs observed in three BH X-ray binaries. It turns out that the 3:2 HFQPO pairs are associated with the steep power-law states, and the severe damping can be overcome by transferring energy and angular momentum from a spinning BH to the inner disc in the MC process.

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arXiv2008

Association of the 3:2 HFQPO Pairs with the Broad Fe K Line in XTE J1550-564 and GRO J1655-40

Association of the high-frequency quasi-periodic oscillation (HFQPO) pairs with the broad Fe K line in XTE J1550-564 and GRO J1655-40 is discussed based on the magnetic coupling (MC) of a rotating black hole (BH) with its surrounding disc. The 3:2 HFQPO pairs are interpreted by virtue of the inner and outer hotspots arising from non-axisymmetric magnetic field, where the inner hotspot is produced by a torque exerted at the inner edge of the disc, and the outer hotspot is created by the screw instability of the large-scale magnetic field. The very steep emissivity index is created predominantly by the torque exerted at the inner edge of the disc. It turns out that the 3:2 HFQPO pairs observed in the two sources can be fitted by tuning several model parameters, such as the BH spin, and the main features of this model lie in three aspects. (1) The condition for only one HFQPO is discussed based on the two mechanisms for producing the 3:2 HFQPO pairs, (2) an explanation is given for a systematic shift away from disc dominated flux with the increasing power-law flux as the HFQPO pairs shift from the higher to lower frequencies, which is consistent with the analysis given by Remillard et al. (2002), and (3) the BH spin in XTE J1550-564 and GRO J1655-40 can be estimated by combining the 3:2 HFQPO pairs with the very steep emissivity index required for fitting the broad Fe K emission line.

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arXiv2007

Effects of Magnetic Fields on Neutrino-dominated Accretion Model for Gamma-ray Bursts

Many models of gamma-ray bursts suggest a common central engine: a black hole of several solar masses accreting matter from a disk at an accretion rate from 0.01 to 10 M_\sun / s. The inner region of the disk is cooled by neutrino emission and large amounts of its binding energy were liberated, which could trigger the fireball. We improve the neutrino-dominated accreting flows by considering the effects of the magnetic fields, and find that more than half of the liberating energy can be extracted directly by the large-scale magnetic fields on the disk. And it turns out that the temperature of the disk is a bit lower than the neutrino-dominated accreting flows without magnetic field. Therefore, The outflows are magneticallydominated rather than neutrino dominated. In our model, neutrino mechanism can fuel some GRBs (not the brightest ones), but cannot fuel X-ray flares. However, the magnetic processes (both BZ and electromagnetic luminosity from a disk) are viable mechanisms for most of GRBs and the following X-ray flares.

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arXiv2007

Correlation between 3:2 QPO pairs and Jets in Black Hole X-ray Binaries

We argue, following our earlier works (the "CEBZMC model"), that the phenomenon of twin peak high frequency quasi-periodic oscillations (QPOs) observed in black hole X-ray binaries is caused by magnetic coupling (MC) between accretion disk and black hole (BH). Due to MC, two bright spots occur at two separate radial locations r_{in} and r_{out} at the disk surface, energized by a kind of the Blandford-Znajek mechanism (BZ). We assume, following the Kluzniak-Abramowicz QPO resonance model, that Keplerian frequencies at these two locations are in the 3:2 ratio. With this assumption, we estimate the BH spins in several sources, including GRO J1655-40, GRS 1915+105, XTE J1550-564, H1743-322 and Sgr A*. We give an interpretation of the "jet line" in the hardness-intensity plane discussing the parameter space consisting of the BH spin and the power-law index for the variation of the large-scale magnetic field in the disk. Furthermore, we propose a new scenario for the spectral state transitions in BH X-ray binaries based on fluctuation in densities of accreting plasma from a companion star.

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