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Related papers: Striations in molecular clouds: Streamers or MHD w…

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Recent observations near the Galactic Centre have found several molecular filaments displaying striking helically-wound morphology, which are collectively known as "molecular tornadoes." We investigate the equilibrium structure of these…

Astrophysics of Galaxies · Physics 2017-07-26 Kelvin Au , Jason D. Fiege

We utilize magnetohydrodynamic (MHD) simulations to develop a numerical model for GMC-GMC collisions between nearly magnetically critical clouds. The goal is to determine if, and under what circumstances, cloud collisions can cause…

Astrophysics of Galaxies · Physics 2015-09-30 Benjamin Wu , Sven Van Loo , Jonathan C. Tan , Simon Bruderer

This study shows the connection between three previously observed but seemingly unrelated phenomena in hydrodynamic (HD) and magnetohydrodynamic (MHD) turbulent flows, involving the emergence of fluctuations occurring on very long time…

Fluid Dynamics · Physics 2015-05-28 P. Dmitruk , P. D. Mininni , A. Pouquet , S. Servidio , W. H. Matthaeus

Recent years have seen the discovery of an ever growing number of stellar debris streams and clouds. These structures are typically detected as extended and often curvilinear overdensities of metal-poor stars that stand out from the…

Astrophysics of Galaxies · Physics 2016-04-06 Carl J. Grillmair , Jeffrey L. Carlin

The study of granular crystals, metamaterials that consist of closely packed arrays of particles that interact elastically, is a vibrant area of research that combines ideas from disciplines such as materials science, nonlinear dynamics,…

Pattern Formation and Solitons · Physics 2017-10-11 C. Chong , Mason A. Porter , P. G. Kevrekidis , C. Daraio

Thin stellar streams, such as those resulting from the tidal disruption of globular clusters, have long been known and used as probes of the gravitational potential of our Galaxy, both its visible and dark contents. In particular, the…

In order to study the fragmentation of massive dense cores, which constitute the cluster cradles, we observed with the PdBI in the most extended configuration the continuum at 1.3 mm and the CO(2-1) emission of four massive cores. We detect…

We calculate the relative grain-grain motions arising from interstellar magnetohydrodynamic (MHD) turbulence. The MHD turbulence includes both fluid motions and magnetic fluctuations. While the fluid motions accelerate grains through…

Astrophysics · Physics 2009-11-10 Huirong Yan , A. Lazarian , B. T. Draine

For et al., who catalogued Magellanic Stream (MS) clouds, suggested that there is substantial large-scale turbulence in the MS. Here we follow up with a series of FLASH simulations that model the hydrodynamic effects that clouds have on…

Astrophysics of Galaxies · Physics 2022-02-14 M. Elliott Williams , Robin L. Shelton

We study the formation of giant dense cloud complexes and of stars within them by means of SPH numerical simulations of the mildly supersonic collision of gas streams (``inflows'') in the warm neutral medium (WNM). The resulting…

Molecular clouds (MC) are structures of dense gas in the interstellar medium (ISM), that extend from ten to a few hundred parsecs and form the main gas reservoir available for star formation. Hydrodynamical simulations of varying complexity…

Radio-wave scintillation observations reveal a nearly Kolmogorov spectrum of density fluctuations in the ionized interstellar medium. Although this density spectrum is suggestive of turbulence, no theory relevant to its interpretation…

Astrophysics · Physics 2009-11-06 Yoram Lithwick , Peter Goldreich

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

Magnetic droplet solitons are dynamical magnetic textures that form due to an attractive interaction between spin waves in thin films with perpendicular magnetic anisotropy. Spin currents and the spin torques associated with these currents…

Mesoscale and Nanoscale Physics · Physics 2020-09-10 Ferran Macià , Andrew D. Kent

We develop a theory for filamentary molecular clouds including the effects of ordered magnetic fields, and external pressure. We first derive a form of the virial equation appropriate for filamentary clouds. By comparing with observational…

Astrophysics · Physics 2007-05-23 Jason D. Fiege , Ralph E. Pudritz

The nearby cloud L1642 is one of only two known very high latitude (|b| > 30 deg) clouds actively forming stars. It is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general,…

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…

Astrophysics of Galaxies · Physics 2015-10-07 S. S. R. Offner , H. G. Arce

We review recent advances in the analytical and numerical modeling of the star formation rate in molecular clouds and discuss the available observational constraints. We focus on molecular clouds as the fundamental star formation sites,…

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

Dynamical instabilities in fluid mechanics are responsible of a variety of important common phenomena, such as waves on the sea surface or Taylor vorteces in Couette flow. In granular media dynamical instabilities has just begun to be…

Soft Condensed Matter · Physics 2007-05-23 Massimo Pica Ciamarra , Mario Nicodemi , Antonio Coniglio