English
Related papers

Related papers: A Super-Alfvenic Model of Dark Clouds

200 papers

We model the polarized thermal dust emission from protostellar cores that are assembled by super-sonic turbulent flows in molecular clouds. Self-gravitating cores are selected from a three dimensional simulation of super-sonic and…

The present work investigates the parametric instability of parallel propagating circularly polarized Alfven(pump) waves in a weakly ionized molecular cloud. It is shown that the relative drift between the plasma particles gives rise to the…

Astrophysics · Physics 2011-02-11 B. P. Pandey , S. V. Vladimirov

The steady, supersonic outflow from the Sun we call the solar wind was first posited in the 1950s and initial theories rightly linked the acceleration of the wind to the existence of the million-degree solar corona. Still today, the wind…

Solar and Stellar Astrophysics · Physics 2016-05-17 Lauren N. Woolsey

We examine the idea that diffuse and giant molecular clouds and their substructure form as density fluctuations induced by large scale interstellar turbulence. We do this by investigating the topology of various fields in realistic…

Astrophysics · Physics 2009-10-30 Javier Ballesteros-Paredes , Enrique Vazquez-Semadeni , John Scalo

We aim to better understand how the spatial structure of molecular clouds is governed by turbulence. For that, we study the large-scale spatial distribution of low density molecular gas and search for characteristic length scales. We employ…

Astrophysics of Galaxies · Physics 2015-05-18 N. Schneider , S. Bontemps , R. Simon , V. Ossenkopf , C. Federrath , R. Klessen , F. Motte , P. Andre , J. Stutzki , C. Brunt

We present a comparison of molecular clouds (MCs) from a simulation of supernova-driven interstellar medium (ISM) turbulence with real MCs from the Outer Galaxy Survey. The radiative transfer calculations to compute synthetic CO spectra are…

Astrophysics of Galaxies · Physics 2016-08-03 Paolo Padoan , Mika Juvela , Liubin Pan , Troels Haugbølle , Åke Nordlund

(abridged) We investigate how the properties of the corona and solar wind in the open coronal holes depend on the properties of the magnetic fields and their footpoint motions at the surface, by perfoming 1D MHD simulations from the…

Astrophysics · Physics 2015-06-24 Takeru K. Suzuki , Shu-ichiro Inutsuka

The interaction of a weakly nonlinear Alfv\'enic pulse with an Alfv\'en speed inhomogeneity in the direction perpendicular to the magnetic field is investigated. Identically to the phase mixing experienced by a harmonic Alfv\'en wave, sharp…

Astrophysics · Physics 2009-11-07 D. Tsiklauri , T. D. Arber , V. M. Nakariakov

We present a comprehensive study of MHD waves and instabilities in a weakly ionised system, e.g., an interstellar molecular cloud. We determine all the critical wavelengths of perturbations across which the sustainable wave modes can change…

Solar and Stellar Astrophysics · Physics 2011-04-01 Telemachos Ch. Mouschovias , Glenn E. Ciolek , S. A. Morton

The recently suggested swing interaction between fast magnetosonic and Alfv\'en waves (2002) is generalized to inhomogeneous media. We show that the fast magnetosonic waves propagating across an applied non-uniform magnetic field can…

Astrophysics · Physics 2007-05-23 B. M. Shergelashvili , T. V. Zaqarashvili , S. Poedts , B. Roberts

Alfv\'en waves are fundamental magnetized modes which play an important role in the dynamics of magnetized flows such as the interstellar medium (ISM). In weakly ionised medium, their propagation critically depends on the ionisation rate…

Astrophysics of Galaxies · Physics 2023-06-21 P. Hennebelle , U. Lebreuilly

Spatial intermittency in decaying kinetic Alfven wave turbulence is investigated to determine if it produces non Gaussian density fluctuations in the interstellar medium. Non Gaussian density fluctuations have been inferred from pulsar…

Astrophysics · Physics 2011-02-11 P. W. Terry , K. W. Smith

We compare the structure of synthetic dust polarization with synthetic molecular line emission from radiative transfer calculations using a 3-dimensional, turbulent collapsing-cloud magnetohydrodynamics simulation. The histogram of relative…

Astrophysics of Galaxies · Physics 2023-03-29 Renato Mazzei , Zhi-Yun Li , Che-Yu Chen , Laura Fissel , Mike Chen , James Park

Magnetic clouds (MCs) are "magnetized plasma clouds" moving in the solar wind. MCs transport magnetic flux and helicity away from the Sun. These structures are not stationary but feature temporal evolution as they propagate in the solar…

Solar and Stellar Astrophysics · Physics 2015-05-30 G. Dalakishvili , J. Kleimann , H. Fichtner , S. Poedts

Complete asymptotic expansions are developed for slow, Alfv\'en and fast magnetohydrodynamic waves at the base of an isothermal three-dimensional (3D) plane stratified atmosphere. Together with existing convergent Frobenius series solutions…

Solar and Stellar Astrophysics · Physics 2021-12-28 Paul S. Cally

Context. Massive stars are generally believed to form in supersonic turbulent environment. However, recent observations have challenged this traditional view. High spatial and spectral resolution observations of the Orion Molecular Cloud…

Astrophysics of Galaxies · Physics 2023-05-31 Chao Wang , Ke Wang

The formation of stars is inextricably linked to the structure of their parental molecular clouds. Here we take a number of nearby giant molecular clouds (GMCs) and analyse their column density and mass distributions. This investigation is…

Astrophysics of Galaxies · Physics 2015-05-18 D. Froebrich , J. Rowles

Alfv\'enic motions are ubiquitous in the solar atmosphere and their observed properties are closely linked to those of photospheric p-modes. However, it is still unclear how a predominantly acoustic wave driver can produce these transverse…

Solar and Stellar Astrophysics · Physics 2023-05-31 Samuel Skirvin , Yuhang Gao , Tom Van Doorsselaere

Supersonic turbulence fragments the interstellar medium into dense sheets, filaments, cores and large low density voids. The turbulence is driven on large scales, probably predominantly by supernovae. The scaling properties of supersonic…

Astrophysics · Physics 2007-05-23 Aake Nordlund , Paolo Padoan

Magnetic fields (B-fields) play an important role in molecular cloud fragmentation and star formation, but are very difficult to detect. The temporal correlation between the field strength (B) and gas density (n) of an isolated cloud has…

Astrophysics of Galaxies · Physics 2023-04-26 Zhuo Cao , Hua-bai Li