201 citations · 2k across the 65 of their papers we have counts for
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Numerical testing of mirror diffusion of cosmic rays
Chao Zhang, Siyao Xu
The tension between recent observations and theories on cosmic ray (CR) diffusion necessitates exploration of new CR diffusion mechanisms. We perform the first numerical study on t…
Mirror acceleration of cosmic rays in a high- medium
Alex Lazarian, Siyao Xu
In a weakly compressible high- medium, pitch-angle scattering and the associated scattering acceleration of cosmic rays (CRs) by anisotropic Alfvén and slow modes of magnetohydr…
Faraday Rotation Measure Variations of Repeating Fast Radio Burst Sources
Yuan-Pei Yang, Siyao Xu, Bing Zhang
Recently, some fast radio burst (FRB) repeaters were reported to exhibit complex, diverse variations of Faraday rotation measures (RMs), which implies that they are surrounded by a…
Cosmic ray streaming in the turbulent interstellar medium
Siyao Xu, Alex Lazarian
We study the streaming instability of GeVGeV cosmic rays (CRs) and its damping in the turbulent interstellar medium (ISM). We find that the damping of streaming instability…
Shock acceleration with oblique and turbulent magnetic fields
Siyao Xu, Alex Lazarian
We investigate shock acceleration in a realistic astrophysical environment with density inhomogeneities. The turbulence induced by the interaction of the shock precursor with upstr…
Diffusion of cosmic rays in MHD turbulence
Siyao Xu
We review some recent findings on diffusion of cosmic rays (CRs) in magnetohydrodynamic (MHD) turbulence obtained by adopting the numerically-tested model of MHD turbulence, includ…
Mirror diffusion of cosmic rays in highly compressible turbulence near supernova remnants
Siyao Xu
Recent gamma-ray observations reveal inhomogeneous diffusion of cosmic rays (CRs) in the interstellar medium (ISM). This is expected as the diffusion of CRs depends on the properti…
Diffusion of cosmic rays in MHD turbulence with magnetic mirrors
Alex Lazarian, Siyao Xu
As the fundamental physical process with many astrophysical implications, the diffusion of cosmic rays (CRs) is determined by their interaction with magnetohydrodynamic (MHD) turbu…
Polarization Predictions in the GRB Prompt Phase with the Internal Shock Model
Mi-Xiang Lan, Hao-Bing Wang, Siyao Xu +2
As the standard gamma-ray burst (GRB) prompt-emission model, the internal shock (IS) model can reproduce the fast-rise and slow-decay features of the pulses in the GRB light curve.…
Probing the intergalactic turbulence with fast radio bursts
Siyao Xu, Bing Zhang
The turbulence in the diffuse intergalactic medium (IGM) plays an important role in various astrophysical processes across cosmic time, but it is very challenging to constrain its…
Nanoflare Theory Revisited
Amir Jafari, Ethan Vishniac, Siyao Xu
Local magnetic reversals are an inseparable part of magnetohydrodynamic (MHD) turbulence whose collective outcome on an arbitrary scale in the inertial range may lead to a global s…
Trapping of cosmic rays in MHD turbulence
Siyao Xu, Alex Lazarian
Astrophysical plasmas are turbulent and magnetized. The interaction between cosmic rays (CRs) and magnetohydrodynamic (MHD) turbulence is a fundamental astrophysical process. Based…
3D Turbulent Reconnection: Theory, Tests and Astrophysical Implications
Alex Lazarian, Gregory L. Eyink, Amir Jafari +4
Magnetic reconnection, topological change in magnetic fields, is a fundamental process in magnetized plasmas. It is associated with energy release in regions of magnetic field anni…
Synchrotron spectra of GRB prompt emission and pulsar wind nebulae
Siyao Xu
Particle acceleration is a fundamental process in many high-energy astrophysical environments and determines the spectral features of their synchrotron emission. We have studied th…
Cosmic ray transport in starburst galaxies
Mark R. Krumholz, Roland M. Crocker, Siyao Xu +3
Starburst galaxies are efficient -ray producers, because their high supernova rates generate copious cosmic ray (CR) protons, and their high gas densities act as thick targets o…
On the broad-band synchrotron spectra of pulsar wind nebulae
Siyao Xu, Noel Klingler, Oleg Kargaltsev +1
As shown by broad-band observations, pulsar wind nebulae (PWNe) are characterized by a broken power-law spectrum of synchrotron emission. Based on the modern magnetohydrodynamic (M…
Resonance-broadened transit time damping of particles in MHD turbulence
Siyao Xu, Alex Lazarian
As a fundamental astrophysical process, the scattering of particles by turbulent magnetic fields has its physical foundation laid by the magnetohydrodynamic (MHD) turbulence theory…
Gamma-ray Bursts Induced by Turbulent Reconnection
Alex Lazarian, Bing Zhang, Siyao Xu
We consider a simple model for gamma-ray bursts induced by magnetic reconnection in turbulent media. The magnetic field in a jet is subject to kink instabilities, which distort the…
On the synchrotron spectrum of GRB prompt emission
Siyao Xu, Yuan-Pei Yang, Bing Zhang
The prompt emission spectrum of Gamma-ray bursts (GRB) is characterized by a smoothly joint broken power-law spectrum known as the Band function. The typical low-energy photon inde…
Magnetic field amplification in supernova remnants
Siyao Xu, Alex Lazarian
Based on the new findings on the turbulent dynamo in \citet{XL16}, we examine the magnetic field amplification in the context of supernova remnants. Due to the strong ion-neutral c…
Adiabatic non-resonant acceleration in magnetic turbulence and hard spectra of gamma-ray bursts
Siyao Xu, Bing Zhang
We introduce a non-resonant acceleration mechanism arising from the second adiabatic invariant in magnetic turbulence and apply it to study the prompt emission spectra of gamma-ray…
TeV Cosmic-Ray Anisotropy from the Magnetic Field at the Heliospheric Boundary
Vanessa López-Barquero, S. Xu, P. Desiati +3
We performed numerical calculations to test the suggestion by Desiati & Lazarian (2013) that the anisotropies of TeV cosmic rays may arise from their interactions with the heliosph…
On the origin of the scatter broadening of fast radio burst pulses and astrophysical implications
Siyao Xu, Bing Zhang
Fast radio bursts (FRBs) have been identified as extragalactic sources which can make a probe of turbulence in the intergalactic medium (IGM) and their host galaxies. To account fo…
Cosmic Ray Small Scale Anisotropies and Local Turbulent Magnetic Fields
Vanessa López-Barquero, R. Farber, S. Xu +2
Cosmic ray anisotropy has been observed in a wide energy range and at different angular scales by a variety of experiments over the past decade. However, no comprehensive or satisf…