相关论文: Cosmic-ray driven dynamo in galactic disks

Observations of large-scale radio emissions prove the existence of shock accelerated cosmic-ray electrons in galaxy clusters, while the lack of detected $\gamma$-rays limits the acceleration of cosmic-ray protons in galaxy clusters. This…

Galactic winds are observed in many spiral galaxies with sizes from dwarfs up to the Milky Way, and they sometimes carry a mass in excess of that of newly formed stars by up to a factor of ten. Multiple driving processes of such winds have…

In the Milky Way, cosmic rays (CRs) are dynamically important in the interstellar medium, contribute to hydrostatic balance, and may help regulate star formation. However, we know far less about the importance of CRs in galaxies whose gas…

Cosmic ray (CR) currents through magnetised plasma drive strong instabilities producing amplification of the magnetic field. This amplification helps explain the CR energy spectrum as well as observations of supernova remnants and radio…

Non-thermal (relativistic) particles are injected into the cosmos by structure formation shock waves, active galactic nuclei and stellar explosions. We present a suite of unigrid cosmological simulations (up to $2048^3$) using a two-fluid…

In star-forming galaxies, the far-infrared (FIR) and radio-continuum luminosities obey a tight empirical relation over a large range of star-formation rates (SFR). We examine magneto-hydrodynamic galaxy simulations with cosmic rays (CRs),…

We have developed a model which aims to reproduce observational data of many kinds related to cosmic-ray origin and propagation: direct measurements of nuclei, antiprotons, electrons and positrons, gamma-rays, and synchrotron radiation. Our…

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for substantial revisions in the picture of cosmic ray transport. In this paper we use recently obtained scaling laws for MHD modes to calculate the scattering…

The turbulent dynamo may explain the origin of cosmic magnetism. While the exponential amplification of magnetic fields has been studied for incompressible gases, little is known about dynamo action in highly-compressible, supersonic…

We analyse the transport of cosmic rays (CR) in magnetic fields that are structured on scales greater than the CR Larmor radius. We solve the Vlasov-Fokker-Planck (VFP) equation for various mixes of mirroring and small-angle scattering and…

This is the first of a series of papers analysing the Galactic Cosmic Ray composition and origin. We show that the Galactic Cosmic Ray source (GCRS) composition is best described in terms of (i) a general enhancement of the refractory…

Galaxies are observed to host magnetic fields with a typical total strength of around 15microgauss. A coherent large-scale field constitutes up to a few microgauss of the total, while the rest is built from strong magnetic fluctuations over…

External cosmic rays impinging upon circumstellar disks associated with young stellar objects provide an important source of ionization, and as such, play an important role in disk evolution and planet formation. However, these incoming…

We simulate an isolated, magnetised Milky Way-like disc galaxy using a self-consistent model of unresolved star formation and feedback, evolving the system until it reaches statistical steady state. We show that the quasi-steady-state…

Cosmic kinematic fast dynamo is found in non-inflationary phases of an ellipsoidal anisotropic cosmological metric background solution of Einstein field equations of general relativity. The magnetic field is amplified inside the universe…

We present results of 2D and 3D PIC simulations of magnetic turbulence production by isotropic cosmic-ray ions drifting upstream of SNR shocks. The studies aim at testing recent predictions of a strong amplification of short wavelength…

Earlier Enqvist and Olesen have shown that formation of ferromagnetic planar walls in vacuum at GUT scales in comoving plasmas may generate a large scale magnetic field of $B_{now}\simeq{10^{-14}G}$. In this paper we show that starting from…

The dynamic processes of magnetic reconnection and turbulence cause magnetic islands/flux-ropes generation. The in-situ observations suggest that the coalescence or/and contraction of magnetic islands are responsible to the charged particle…

The escape of cosmic rays from the Galaxy leads to a gradient in the cosmic ray pressure that acts as a force on the background plasma, in the direction opposite to the gravitational pull. If this force is large enough to win against…

The evolution of three-dimensional, large-scale, magnetic fields, in a galactic disk is investigated numerically. The N-body simulations of galactic dynamics are incorporated into the kinematic calculations of induction equations to study…