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Related papers: The Density Variance Mach Number Relation in the T…

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Velocity anisotropy induced by MHD turbulence is investigated using computational simulations and molecular line observations of the Taurus molecular cloud. A new analysis method is presented to evaluate the degree and angle of velocity…

Astrophysics · Physics 2009-11-13 Mark Heyer , Hao Gong , Eve Ostriker , Christopher Brunt

We examine the physical parameters that affect the accumulation of gas in molecular clouds to high column densities where the formation of stars takes place. In particular, we analyze the dense gas mass fraction (DGMF) in a set of…

Astrophysics of Galaxies · Physics 2015-06-15 Jouni Kainulainen , Christoph Federrath , Thomas Henning

The density variance - Mach number relation of the turbulent interstellar medium is relevant for theoretical models of the star formation rate, efficiency, and the initial mass function of stars. Here we use high-resolution hydrodynamical…

Astrophysics of Galaxies · Physics 2015-05-08 Christopher A. Nolan , Christoph Federrath , Ralph S. Sutherland

The nature of turbulence in molecular clouds is one of the key parameters that control star formation efficiency: compressive motions, as opposed to solenoidal motions, can trigger the collapse of cores, or mark the expansion of Hii…

Firstly, we give a historical overview of attempts to incorporate magnetic fields into the Smoothed Particle Hydrodynamics method by solving the equations of Magnetohydrodynamics (MHD), leading an honest assessment of the current…

Astrophysics of Galaxies · Physics 2015-05-20 Daniel J. Price

We present a direct numerical and analytical study of driven supersonic MHD turbulence that is believed to govern the dynamics of star-forming molecular clouds. We describe statistical properties of the turbulence by measuring the velocity…

Astrophysics · Physics 2009-11-07 Stanislav Boldyrev , Aake Nordlund , Paolo Padoan

Turbulence dissipation is an important process affecting the energy balance in molecular clouds, the birth place of stars. Previously, the rate of turbulence dissipation is often estimated with semi-analytic formulae from simulation.…

Instrumentation and Methods for Astrophysics · Physics 2018-10-10 Lei Qian , Di Li , Yang Gao , Haitao Xu , Zhichen Pan

We present an analytical model of the relation between the surface density of gas and star formation rate in galaxies and clouds, as a function of the presence of supersonic turbulence and the associated structure of the interstellar…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-06 Florent Renaud , Katarina Kraljic , Frédéric Bournaud

Young stars form in molecular cores, which are dense condensations within molecular clouds. We have searched for molecular cores traced by $^{13}$CO $J=1\to 0$ emission in the Taurus molecular cloud and studied their properties. Our data…

Astrophysics of Galaxies · Physics 2015-06-05 Lei Qian , Di Li , Paul Goldsmith

The FCRAO Survey of the Taurus Molecular Cloud observed the 12CO and 13CO J=1-0 emission from 98 square degrees of this important, nearby star forming region. This set of data with 45" resolution comprises the highest spatial dynamic range…

The star formation rate (SFR), the number of stars formed per unit of time, is a fundamental quantity in the evolution of the Universe. While turbulence is believed to play a crucial role in setting the SFR, the exact mechanism remains…

Astrophysics of Galaxies · Physics 2024-10-02 Patrick Hennebelle , Noé Brucy , Tine Colman

Supersonic flows in the interstellar medium (ISM) are believed to be a key driver of the molecular cloud formation and evolution. Among molecular clouds' properties, the ratio between the solenoidal and compressive modes of turbulence plays…

Astrophysics of Galaxies · Physics 2022-05-18 Masato I. N. Kobayashi , Tsuyoshi Inoue , Kengo Tomida , Kazunari Iwasaki , Hiroki Nakatsugawa

Supersonic turbulence results in strong density fluctuations in the interstellar medium (ISM), which have a profound effect on the chemical structure. Particularly useful probes of the diffuse ISM are the ArH$^+$, OH$^+$, H$_2$O$^+$…

Astrophysics of Galaxies · Physics 2019-11-12 Shmuel Bialy , David Neufeld , Mark Wolfire , Amiel Sternberg , Blakesley Burkhart

We compute the structure function scaling of a 2MASS extinction map of the Taurus molecular cloud complex. The scaling exponents of the structure functions of the extinction map follow the Boldyrev's velocity structure function scaling of…

Astrophysics · Physics 2009-11-07 Paolo Padoan , Laurent Cambresy , William Langer

The most extensive survey of carbon monoxide (CO) gas in the Taurus molecular cloud relied on $^{12}$CO and $^{13}$CO $J=1 \rightarrow 0$ emission only, distinguishing the region where $^{12}$CO is detected without $^{13}$CO (named mask 1…

Astrophysics of Galaxies · Physics 2023-08-02 Yan Duan , Di Li , Laurent Pagani , Paul F. Goldsmith , Tao-Chung Ching , Chen Wang , Jinjin Xie

We present a study of the three-dimensional (3D) distribution of interstellar dust derived from stellar extinction observations toward the Taurus molecular cloud (MC) and its relation with the neutral atomic hydrogen (HI) emission at 21 cm…

In this contribution, we test our previously published one-dimensional PDR model for deriving total hydrogen volume densities from HI column density measurements in extragalactic regions by applying it to the Taurus molecular cloud, where…

Astrophysics of Galaxies · Physics 2015-06-12 J. S. Heiner , E. Vázquez-Semadeni

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…

Herschel observations have emphasized the role of molecular filaments in star formation. However, the origin and evolution of these filaments are not yet well understood, partly because of the lack of kinematic information. To examine…

Astrophysics of Galaxies · Physics 2019-02-27 Y. Shimajiri , Ph. Andre , P. Palmeirim , D. Arzoumanian , A. Bracco , V. Konyves , E. Ntormousi , B. Ladjelate

The density distribution of supersonic isothermal turbulence plays a critical role in many astrophysical systems. It is commonly approximated by a lognormal distribution with a variance of $\sigma_{s,{\rm V}}^2 \approx \ln(1 + b^2 M_{\rm…

Astrophysics of Galaxies · Physics 2026-01-15 Evan Scannapieco , Marcus Brüggen , Philipp Grete , Liubin Pan