相关论文: A Super-Alfvenic Model of Dark Clouds
We show that it is possible to measure Alfv\'enic Mach numbers, defined as the shock velocity in the flow divided by the Alfv\'en velocity, for low-velocity (V$_{shock}$ $\lesssim$ 100 km$\,$s$^{-1}$) radiative shocks. The method combines…
Plasma processes close to SNR shocks result in the amplification of magnetic fields and in the acceleration of electrons, injecting them into the diffusive acceleration mechanism. The acceleration of electrons and the B field amplification…
We analyse extinction maps of nearby Giant Molecular Clouds to forge a link between driving processes of turbulence and modes of star formation. Our investigation focuses on cloud structure in the column density range above the self…
We show radio continuum images of several molecular complexes in the inner Galaxy and report the presence of dark features that coincide with dense molecular clouds. Unlike infrared dark clouds, these features which we call "radio dark…
We investigate the formation of molecular clouds from atomic gas by using three-dimensional magnetohydrodynamic simulations, including non-equilibrium chemical reactions and heating/cooling processes. We consider super-Alfv\'enic head-on…
We developed a magneto-turbulent model for the cosmic ray (CR) electrons seen in the radio halo clusters of galaxies. Steady state momentum distribution functions of the CR electrons are calculated for given spectra of the turbulent Alfven…
The molecular component of the Galaxy is comprised of turbulent, magnetized clouds, many of which are self-gravitating and form stars. To understand how these clouds' evolution may depend on their level of turbulence, mean magnetization,…
We determine the physical properties and turbulence driving mode of molecular clouds formed in numerical simulations of a Milky Way-type disc galaxy with parsec-scale resolution. The clouds form through gravitational fragmentation of the…
The turbulent destruction of a cloud subject to the passage of an adiabatic shock is studied. We find large discrepancies between the lifetime of the cloud and the analytical result of Hartquist et al. (1986). These differences appear to be…
Alfv\'en vortex is a multi-scale nonlinear structure which contributes to intermittency of turbulence. Despite previous explorations mostly on the spatial properties of the Alfv\'en vortex (i.e., scale, orientation, and motion), the plasma…
We compare the statistical properties of J=1-0 13CO spectra observed in the Perseus Molecular Cloud with synthetic J=1-0 13CO spectra from a 5 pc model cloud. The synthetic spectra are computed solving the non-LTE radiative transfer problem…
Observations of nearby molecular clouds detect "shells", which are likely caused by winds from young main sequence stars. However, the progenitors of these observed features are not well characterized and the mass-loss rates inferred from…
M dwarf's atmosphere is expected to be highly magnetized. The magnetic energy can be responsible for heating the stellar chromosphere and corona, and driving the stellar wind. The nonlinear propagation of Alfv\'en wave is the promising…
Molecular clouds (MCs) are stellar nurseries, however, formation of stars within MCs depends on the ambient physical conditions. MCs, over a free-fall time are exposed to numerous dynamical phenomena, of which, the interaction with a thin,…
Observed molecular clouds often appear to have very low star formation efficiencies and lifetimes an order of magnitude longer than their free-fall times. Their support is attributed to the random supersonic motions observed in them. We…
The center of the Milky Way galaxy (MW) is an extreme environment which contains a massive black hole surrounded by a very dense star cluster, two other adjacent star clusters, and a giant molecular cloud which would serve as an incubator…
We investigate, through a series of numerical calculations, the evolution of dense cores that are accreting external gas up to and beyond the point of star formation. Our model clouds are spherical, unmagnetized configurations with fixed…
We study, by numerical simulations, the entrainment process in a supersonic, radiative jet flow, during the evolution of Kelvin-Helmholtz instabilities, in the context of the the acceleration problem of molecular bipolar outflows, observed…
Within ten nearby (d < 450 pc) Gould Belt molecular clouds we evaluate statistically the relative orientation between the magnetic field projected on the plane of sky, inferred from the polarized thermal emission of Galactic dust observed…
There are in the literature several theories to explain the mass loss in stellar winds. In particular, for late-type stars, some authors have proposed a wind model driven by an outward-directed flux of damped Alfven waves. The winds of…