English
Related papers

Related papers: Testing Molecular-Cloud Fragmentation Theories: Se…

200 papers

We present an investigation on effect of the ion-neutral (or ambipolar) diffusion heating rate on thermal phases of a molecular cloud. We use the modeling of ambipolar diffusion with two-fluid smoothed particle hydrodynamics, as discussed…

Astrophysics · Physics 2008-04-29 M. Nejad-Asghar , D. Molteni

We attempt to verify recent claims (made using semi-analytic models) that for the collapse of spherical homogeneous molecular clouds, fragmentation of the self-gravitating disc that subsequently forms can be predicted using the cloud's…

Solar and Stellar Astrophysics · Physics 2015-05-30 Duncan Forgan , Ken Rice

The collapse and fragmentation of initially filamentary, magnetic molecular clouds is calculated in three dimensions with a gravitational, radiative hydrodynamics code. The code includes magnetic field effects in an approximate manner:…

Astrophysics · Physics 2015-06-24 Alan P. Boss

Cloud evolution for various metallicities is investigated by three-dimensional nested grid simulations, in which the initial ratio of rotational to gravitational energy of the host cloud \beta_0 (=10^-1 - 10^-6) and cloud metallicity Z (=0…

Astrophysics · Physics 2009-11-13 Masahiro N. Machida

We present a new method to study the characteristic scales of collapse and fragmentation in galactic disks. Clump formation is seeded in simulations via controlled perturbations with a specified wavelength and velocity. These are applied to…

Astrophysics of Galaxies · Physics 2019-05-08 S. M. Benincasa , J. W. Wadsley , H. M. P. Couchman , A. R. Pettit , E. J. Tasker

We numerically reproduce the density profiles for filaments that are in magnetohydrostatic and pressure equilibrium with their surroundings obtained in Tomisaka (2014) and show that these equilibria are dynamically stable. If the effect of…

Astrophysics of Galaxies · Physics 2016-11-30 C. A. Burge , S. Van Loo , S. A. E. G. Falle , T. W. Hartquist

To understand the formation of stars from clouds of molecular gas, one essentially needs to know two things: What gas collapses, and how long it takes to do so. We address these questions by embedding pseudo-Lagrangian tracer particles in…

Astrophysics of Galaxies · Physics 2022-10-12 David C. Collins , Dan K. Le , Luz L. Jimenez Vela

We report ALMA Band 6 continuum observations of 2000 AU resolution toward four massive molecular clouds in the Central Molecular Zone of the Galaxy. To study gas fragmentation, we use the dendrogram method to identify cores as traced by the…

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

Recently it was shown that self-organized criticality is an important ingredient of the dynamics of cumulus clouds (Physical Review E, 103(5), p.052106, 2021). Here we introduce a new algorithm to simulate cumulus clouds in two-dimensional…

Statistical Mechanics · Physics 2022-12-07 J. Cheraghalizadeh , M. Luković , M. N. Najafi

Galactic winds exhibit a multiphase structure that consists of hot-diffuse and cold-dense phases. Here we present high-resolution idealised simulations of the interaction of a hot supersonic wind with a cold cloud with the moving-mesh code…

Astrophysics of Galaxies · Physics 2018-11-28 Martin Sparre , Christoph Pfrommer , Mark Vogelsberger

We review theoretical models of the early stages of star formation, in which gravitational collapse is strongly regulated by magnetic fields and the associated process of ambipolar diffusion. We discuss results of numerical simulations and…

Astrophysics · Physics 2007-05-23 Glenn E. Ciolek , Shantanu Basu

The dynamical instability of a self-gravitating magnetized filamentary cloud was investigated while taking account of rotation around its axis. The filamentary cloud of our model is supported against self-gravity in part by both a magnetic…

Astrophysics · Physics 2007-05-23 Tomoaki Matsumoto , Fumitaka Nakamura , Tomoyuki Hanawa

Super-sonic turbulence fragments molecular clouds (MC) into a very complex density field with density contrasts of several orders of magnitude. A fraction of the gas is locked into dense and gravitationally bound cores, which collapse as…

Astrophysics · Physics 2007-05-23 Paolo Padoan , AAke Nordlund , Ornolfur Einar Rognvaldsson , Alyssa Goodman

We investigate the role of ambipolar diffusion (AD) in collisions between magnetized giant molecular clouds (GMCs), which may be an important mechanism for triggering star cluster formation. Three dimensional simulations of GMC collisions…

Astrophysics of Galaxies · Physics 2017-10-18 Duncan Christie , Benjamin Wu , Jonathan C. Tan

From air-sea gas exchange, oil pollution, to bioreactors, the ubiquitous fragmentation of bubbles/drops in turbulence has been modelled by relying on the classical Kolmogorov-Hinze paradigm since the 1950s. This framework hypothesizes that…

Fluid Dynamics · Physics 2022-01-26 Yinghe Qi , Shiyong Tan , Noah Corbitt , Carl Urbanik , Ashwanth K. R. Salibindla , Rui Ni

We investigate differences in the molecular abundances between magnetically super- and sub-critical prestellar cores, performing three-dimensional non-ideal magnetohydrodynamical (MHD) simulations with varying densities and magnetic field…

Astrophysics of Galaxies · Physics 2019-07-17 Felix D. Priestley , James Wurster , Serena Viti

Observations suggest that star formation in filamentary molecular clouds occurs in a two-step process, with the formation of filaments preceding that of prestellar cores and stars. Here, we apply the gravo-turbulent fragmentation theory of…

Astrophysics of Galaxies · Physics 2017-10-04 Yueh-Ning Lee , Patrick Hennebelle , Gilles Chabrier

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

Recent progress in the understanding of star formation is summarized. A consistent picture is emerging where molecular clouds form with turbulent velocity fields and clumpy substructure, imprinted already during their formation. The clouds…

Astrophysics · Physics 2007-05-23 Andreas Burkert
‹ Prev 1 3 4 5 6 7 10 Next ›