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This study is aimed to contribute to a more comprehensive understanding of the molecular hydrogen distribution in the galaxy M33 by introducing novel methods for generating high angular resolution (18.2$''$, equivalent to 75 pc) column…

To evaluate the effect of turbulent heating in the thermal balance of interstellar clouds, we develop an extension of the log-Poisson intermittency model to supersonic turbulence. The model depends on a parameter, d, interpreted as the…

Astrophysics · Physics 2011-02-11 Liubin Pan , Paolo Padoan

[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'',…

The fragmentation of gas to form stars in molecular clouds is intrinsically linked to the turbulence within them. These internal motions are set at the birth of the cloud and may vary with galactic environment and as the cloud evolves. In…

Astrophysics of Galaxies · Physics 2024-07-29 Jiten Dhandha , Zoe Faes , Rowan J. Smith

Observations of magnetic field strengths imply that molecular cloud fragments are individually close to being in a magnetically critical state, even though both magnetic field and column density measurements range over two orders of…

Astrophysics · Physics 2007-05-23 Shantanu Basu

Stars form within molecular clouds but our understanding of this fundamental process remains hampered by the complexity of the physics that drives their evolution. We review our observational and theoretical knowledge of molecular clouds…

Astrophysics of Galaxies · Physics 2015-06-12 Patrick Hennebelle , Edith Falgarone

Passive scalar mixing (metals, molecules, etc.) in the turbulent interstellar medium (ISM) is critical for abundance patterns of stars and clusters, galaxy and star formation, and cooling from the circumgalactic medium. However, the…

Astrophysics of Galaxies · Physics 2017-03-22 Matthew J. Colbrook , Xiangcheng Ma , Philip F. Hopkins , Jonathan Squire

We used magnetohydrodynamic (MHD) simulations of interstellar turbulence to study the probability distribution functions (PDFs) of increments of density, velocity, and magnetic field. We found that the PDFs are well described by a Tsallis…

Astrophysics of Galaxies · Physics 2011-08-04 A. Esquivel , A. Lazarian

Studies of disordered heterogeneous media and galaxy cosmology share a common goal: analyzing the distribution of particles at `microscales' to predict physical properties at `macroscales', whether for a liquid, composite material, or…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Oliver H. E. Philcox , Salvatore Torquato

We explore whether observed molecular clouds could include a substantial population of unbound clouds. Using simulations which include only turbulence and gravity, we are able to match observed relations and naturally reproduce the observed…

Astrophysics of Galaxies · Physics 2014-03-05 Rachel L. Ward , James Wadsley , Alison Sills

The joint probability distribution function (PDF) of the density within multiple concentric spherical cells is considered. It is shown how its cumulant generating function can be obtained at tree order in perturbation theory as the Legendre…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-19 Francis Bernardeau , Christophe Pichon , Sandrine Codis

Observations reveal a uniform Kolmogorov turbulence throughout the diffuse ionized interstellar medium (ISM) and supersonic turbulence preferentially located in the Galactic plane. Correspondingly, we consider the Galactic distribution of…

Astrophysics of Galaxies · Physics 2017-01-25 Siyao Xu , Bing Zhang

We investigate the core mass distribution (CMD) resulting from numerical models of turbulent fragmentation of molecular clouds. In particular we study its dependence on the sonic root-mean-square Mach number $\Ms$. We analyze simulations…

This paper gives a new way to diagnose the star-forming potential of a molecular cloud region from the probability density function of its column density (N-pdf). It gives expressions for the column density and mass profiles of a symmetric…

Astrophysics of Galaxies · Physics 2015-05-06 Philip C. Myers

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…

Astrophysics · Physics 2009-11-13 Stella S. R. Offner , Richard I. Klein , Christopher F. McKee

The macroscopic behavior of dense suspensions of neutrally-buoyant spheres in turbulent plane channel flow is examined. We show that particles larger than the smallest turbulence scales cause the suspension to deviate from the continuum…

Fluid Dynamics · Physics 2016-09-28 Pedro Costa , Francesco Picano , Luca Brandt , Wim-Paul Breugem

An investigation of the effect of surface diffusion in random deposition model is made by analytical methods and reasoning. For any given site, the extent to which a particle can diffuse is decided by the morphology in the immediate…

Soft Condensed Matter · Physics 2011-12-14 Baisakhi Mal , Subhankar Ray , J. Shamanna

Star formation is primarily controlled by the interplay between gravity, turbulence, and magnetic fields. However, the turbulence and magnetic fields in molecular clouds near the Galactic Center may differ substantially from spiral-arm…

The observed rapid onset of star formation in molecular clouds requires rapid formation of dense fragments which can collapse individually before being overtaken by global gravitationally-driven flows. Many previous investigations have…

Astrophysics · Physics 2009-11-13 F. Heitsch , L. Hartmann , A. Burkert , ;

The Galactic interstellar turbulence affects the density distribution and star formation. We introduce a new method of measuring interstellar turbulent density spectra by using the dispersion measures (DMs) of a large sample of pulsars.…

Astrophysics of Galaxies · Physics 2021-01-06 Siyao Xu , Bing Zhang
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