Related papers: Can Protostellar Jets Drive Supersonic Turbulence …
Jets, collimated outflows of particles and fields, are observed in a wide variety of astrophysical systems, including Active Galactic Nuclei of various types, microquasars, gamma-ray bursts, and young stellar objects. Despite intensive…
We investigate the evolution of a disk wind into a collimated jet under the influence of magnetic diffusivity, assuming that the turbulent pattern in the disk will also enter the disk corona and the jet. Using the ZEUS-3D code in the…
Supersonic turbulence plays a pivotal role during the formation of molecular clouds and stars in galaxies. However, little is known about how the fraction of compressive and solenoidal modes in the velocity field evolves over time and how…
[abridged] We investigate the velocity structure of protostellar cores that result from non-magnetic numerical models of the gravoturbulent fragmentation of molecular cloud material. A large fraction of the cores analyzed are ``quiescent'',…
In this study we investigate the formation and properties of prestellar and protostellar cores using hydrodynamic, self-gravitating Adaptive Mesh Refinement simulations, comparing the cases where turbulence is continually driven and where…
We explore the physics of time-dependent hydrodynamic collimation of jets from Young Stellar Objects (YSOs). Using parameters appropriate to YSOs we have carried out high resolution hydrodynamic simulations modeling the interaction of a…
Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after…
We present two-dimensional slab-jet simulations of jets in inhomogeneous media consisting of a tenuous hot medium populated with a small filling factor by warm, dense clouds. The simulations are relevant to the structure and dynamics of…
Recent observations of column densities in molecular clouds find lognormal distributions with power-law high-density tails. These results are often interpreted as indications that supersonic turbulence dominates the dynamics of the observed…
A protostellar jet and outflow are calculated for \sim 270 yr following the protostar formation using a three dimensional magnetohydrodynamics simulation, in which both the protostar and its parent cloud are spatially resolved. A…
An overview is presented of the main properties of the interstellar medium. Evidence is summarized that the interstellar medium is highly turbulent, driven on different length scales by various energetic processes. Large-scale turbulence…
Acoustic droplet vaporization denotes the phase-change of micron- and sub-micron-sized droplets upon the application of high-amplitude ultrasound. The asymmetric collapse of the incepted vapor bubbles within the droplets can give rise to…
Turbulence is ubiquitous in molecular clouds (MCs), but its origin is still unclear because MCs are usually assumed to live longer than the turbulence dissipation time. Interstellar medium (ISM) turbulence is likely driven by SN explosions,…
We evaluate whether dissipation of turbulence injected into hot cluster atmospheres by jets and bubbles can offset radiative cooling flows. No trends are found between atmospheric velocity dispersion, $\sigma_v$, and either the ratio of…
Molecular clouds have broad linewidths suggesting turbulent supersonic motions in the clouds. These motions are usually invoked to explain why molecular clouds take much longer than a free-fall time to form stars. It has classically been…
We have investigated how several parameters can affect the results of a collision between an extragalactic jet and a dense, intergalactic cloud, through a series of hydrodynamic simulations. Such collisions are often suggested to explain…
Powerful, highly collimated jets, surrounded by bipolar molecular outflows, are commonly observed near Young Stellar Objects (YSOs). In the usual theoretical picture of star formation, a jet is ejected from a magnetized accretion disk, with…
Jets from young stars represent one of the most striking signposts of star formation. The phenomenon has been researched for over two decades and there is now general agreement that such jets are generated as a by-product of accretion; most…
Jets are found in a variety of astrophysical sources, from young stellar objects to active galactic nuclei. In all the cases the jet propagates with a supersonic velocity through the external medium, which can be inhomogeneous, and…
Supersonic turbulence is an essential element in understanding how structure within interstellar gas is created and shaped. In the context of star formation, many computational studies show that the mass spectrum of density and velocity…