English
Related papers

Related papers: The magnetic field structure in molecular cloud fi…

200 papers

Non-linear simulations of filament propagation in a realistic MAST SOL flux tube geometry using the BOUT++ fluid modelling framework show an isolation of the dynamics of the filament in the divertor region from the midplane region due to…

Plasma Physics · Physics 2015-06-16 Nicholas Walkden , Benjamin Dudson , Geoff Fishpool

One of the key problems in star formation research is to determine the role of magnetic fields. Starting from the atomic inter-cloud medium (ICM) which has density nH ~ 1 per cubic cm, gas must accumulate from a volume several hundred pc…

Astrophysics of Galaxies · Physics 2015-05-13 Hua-bai Li , C. Darren Dowell , Alyssa Goodman , Roger Hildebrand , Giles Novak

Simulations are presented of the photoionisation of three dense gas clouds threaded by magnetic fields, showing the dynamical effects of different initial magnetic field orientations and strengths. For moderate magnetic field strengths the…

Astrophysics of Galaxies · Physics 2013-01-08 Jonathan Mackey , Andrew J. Lim

Magnetic field are transported and tangled by turbulence, even as they lose identity due to nonideal or resistive effects. On balance field lines undergo stretch-twist-fold processes. The curvature field, a scalar that measures the tangling…

We perform numerical magnetohydrodynamic (MHD) simulations of the gravitational collapse and fragmentation of a cylindrical molecular cloud with the help of the FLASH code. The cloud collapses rapidly along its radius without any signs of…

Astrophysics of Galaxies · Physics 2024-05-15 I. M. Sultanov , S. A. Khaibrakhmanov

In order to develop a more comprehensive picture of star formation, it is essential to understand the physical relationship between dense cores and the filaments embedding them. There is evidence that magnetic fields play a crucial role in…

Filament G37 exhibits a distinctive "caterpillar" shape, characterized by two semicircular structures within its 40\,pc-long body, providing an ideal target to investigate the formation and evolution of filaments. By analyzing multiple…

Astrophysics of Galaxies · Physics 2025-04-30 Mengke Zhao , Xindi Tang , Keping Qiu , Yuxin He , Dalei Li

We analyse the morphology and kinematics of dense filamentary structures produced in a numerical simulation of a star--forming cloud of $1.4 \times 10^4 \, \Msun$ evolving under their own self--gravity in a magnetized medium. This study is…

Astrophysics of Galaxies · Physics 2017-09-20 Manuel Zamora-Avilés , Javier Ballesteros-Paredes , Lee W. Hartmann

Filamentary molecular clouds are regarded as the place where newborn stars are formed. In particular, a hub region, a place where it appears as if several filaments are colliding, often indicates active star formation. To understand the…

Astrophysics of Galaxies · Physics 2023-09-06 Raiga Kashiwagi , Kazunari Iwasaki , Kohji Tomisaka

We present idealized numerical simulations of prestellar gravitational collapse of a moderate initial filamentary perturbation with an additional central ellipsoidal enhancement (a core) considering a uniform, and a stratified background,…

Astrophysics of Galaxies · Physics 2022-01-12 Raúl Naranjo-Romero , Enrique Vázquez-Semadeni , Robert M. Loughnane

We have used the AMR hydrodynamic code, MG, to perform idealised 3D MHD simulations of the formation of clumpy and filamentary structure in a thermally unstable medium without turbulence. A stationary thermally unstable spherical diffuse…

Astrophysics of Galaxies · Physics 2016-03-23 C. J. Wareing , J. M. Pittard , S. A. E. G. Falle , S. Van Loo

Cloud-cloud collisions are expected to trigger star formation by compressing gas into dense, gravitationally unstable regions. However, the role of magnetic fields in this process is unclear. We use SPH to model head-on collisions between…

Astrophysics of Galaxies · Physics 2026-01-19 Theotokis Georgatos , Anthony P. Whitworth

While the magnetic field in quiescent prominences has been widely investigated, less is known about the field in activated prominences. We introduce observational results on the magnetic field structure of an activated filament in a flaring…

Solar and Stellar Astrophysics · Physics 2015-06-18 C. Sasso , A. Lagg , S. K. Solanki

Most molecular clouds are filamentary or elongated. Among those forming low-mass stars, their long axes tend to be either parallel or perpendicular to the large-scale (10-100 pc) magnetic field (B-field) in the surrounding inter cloud…

Astrophysics of Galaxies · Physics 2015-10-27 Hua-bai Li , Ka Ho Yuen , Frank Otto , Po Kin Leung , T. K. Sridharan , Qizhou Zhang , Hauyu Liu , Ya-Wen Tang , Keping Qiu

We investigate, through 2D MHD numerical simulations, the interaction of a uniform magnetic field oblique to a moving interstellar cloud. In particular we explore the transformation of cloud kinetic energy into magnetic energy as a result…

Astrophysics · Physics 2016-08-30 Francesco Miniati , T. W. Jones , Dongsu Ryu

A fully three-dimensional computation of induction processes in a disk is performed to investigate the evolution of a large-scale magnetic field in gas-rich barred and spiral galaxies in the presence of field diffusion. As input parameters…

Astrophysics · Physics 2007-05-23 S. von Linden , K. Otmianowska-Mazur , H. Lesch , G. Skupniewicz

We studied the collapse of rotating molecular cloud cores with inclined magnetic fields, based on three-dimensional numerical simulations.The numerical simulations start from a rotating Bonnor-Ebert isothermal cloud in a uniform magnetic…

Astrophysics · Physics 2009-11-11 Masahiro N. Machida , Tomoaki Matsumoto , Tomoyuki Hanawa , Kohji Tomisaka

Polarimetry is one of the most informative techniques of studying magnetic fields in molecular clouds. How reliable the interpretation of the polarization maps in terms of magnetic fields is the issue that the grain alignment theory…

Astrophysics · Physics 2016-08-30 A. Lazarian , J. Cho

Two counter-propagating cool and equally dense electron beams are modelled with particle-in-cell (PIC) simulations. The electron beam filamentation instability is examined in one spatial dimension, which is an approximation for a…

Plasma Physics · Physics 2015-05-13 M. E. Dieckmann , I. Kourakis , M. Borghesi , G. Rowlands