中文
相关论文

相关论文: A multi-shock model for the density variance of an…

200 篇论文

The probability density function (PDF) of the gas density in subsonic and supersonic, isothermal, driven turbulence is analyzed with a systematic set of hydrodynamical grid simulations with resolutions up to 1024^3 cells. We performed a…

太阳与恒星天体物理 · 物理学 2014-11-27 Lukas Konstandin , Philipp Girichidis , Christoph Federrath , Ralf S. Klessen

We compare the statistical properties of J=1-0 13CO spectra observed in the Perseus Molecular Cloud with synthetic J=1-0 13CO spectra, computed solving the non-LTE radiative transfer problem for a model cloud obtained as solutions of the…

天体物理学 · 物理学 2015-06-24 Paolo Padoan , John Bally , Youssef Billawala , Mika Juvela , AAke Nordlund

[abridged] We determine the relationship between turbulence energy and gas density variance for 15 molecular clouds in the Solar neighbourhood. We use the linewidths of the CO molecule as the probe of the turbulence energy (sonic Mach…

星系天体物理 · 物理学 2017-12-06 Jouni Kainulainen , Christoph Federrath

Turbulence in the weakly collisional intracluster medium of galaxies (ICM) is able to generate strong thermal velocity anisotropies in the ions (with respect to the local magnetic field direction), if the magnetic moment of the particles is…

宇宙学与河外天体物理 · 物理学 2016-05-18 R. Santos-Lima , H. Yan , E. M. de Gouveia Dal Pino , A. Lazarian

The role of supersonic turbulence in structuring the interstellar medium (ISM) remains an unsettled question. Here, this problem is investigated using a newexact law of compressible isothermal hydrodynamic turbulence, which involves…

星系天体物理 · 物理学 2023-03-14 Renaud Ferrand , Sébastien Galtier , Fouad Sahraoui , Christoph Federrath

We present magnetohydrodynamic simulations aimed at studying the effect of the magnetic suppression of turbulence (generated through various instabilities during the formation of molecular clouds by converging) on the subsequent star…

Although there are a wealth of column density tracers for both the molecular and diffuse interstellar medium, there are very few observational studies investigating the relationship between the density variance ($\sigma^2$) and the sonic…

星系天体物理 · 物理学 2015-06-05 Blakesley Burkhart , A. Lazarian

We investigate the nature and spatial variations of turbulence in the Small Magellanic Cloud (SMC) by applying several statistical methods on the neutral hydrogen (HI) column density image of the SMC and a database of isothermal numerical…

星系天体物理 · 物理学 2014-11-20 Blakesley Burkhart , Snezana Stanimirovic , Alex Lazarian , Grzegorz Kowal

The atomic-to-molecular (HI-to-H$_2$) transition in photodissociation regions (PDRs) has been investigated over the last several decades through analytic and numerical modeling. However, classical PDR models typically assume uniform density…

星系天体物理 · 物理学 2021-01-06 Yue Hu , A. Lazarian , Shmuel Bialy

Turbulence is ubiquitous in molecular clouds (MCs), but its origin is still unclear because MCs are usually assumed to live longer than the turbulence dissipation time. Interstellar medium (ISM) turbulence is likely driven by SN explosions,…

星系天体物理 · 物理学 2016-05-04 Paolo Padoan , Liubin Pan , Troels Haugboelle , Ake Nordlund

We propose that galactic shocks propagating through interstellar density fluctuations provide a mechanism for the intermittent replenishment, or "pumping," of the supersonic motions and internal density enhancements observed pervasively…

天体物理学 · 物理学 2008-02-03 Paul Kornreich , John Scalo

There is considerable evidence for widespread subsonic turbulence in galaxy clusters, most notably from {\it Hitomi}. Turbulence is often invoked to offset radiative losses in cluster cores, both by direct dissipation and by enabling…

星系天体物理 · 物理学 2023-01-18 Chaoran Wang , S. Peng Oh , M. Ruszkowski

High Reynolds number isotropic magneto-hydro-dynamic turbulence in the presence of large scale magnetic fields is investigated as a function of the magnetic field strength. For a variety of flow configurations the energy dissipation rate…

流体动力学 · 物理学 2012-09-20 Alexandros Alexakis

Supersonic turbulence is believed to be at the heart of star formation. We have performed smoothed particle magnetohydrodynamics (SPMHD) simulations of the small-scale dynamo amplification of magnetic fields in supersonic turbulence. The…

天体物理仪器与方法 · 物理学 2016-06-03 Terrence S. Tricco , Daniel J. Price , Christoph Federrath

The Herschel Gould Belt Survey showed that stars form in dense filaments in nearby molecular clouds. Recent studies suggest that massive filaments are bound by the slow shocks caused by accretion flows onto the filaments. The slow shock is…

星系天体物理 · 物理学 2023-10-26 Daisei Abe , Tsuyoshi Inoue , Shu-ichiro Inutsuka

This work presents a new physical model of the star formation rate (SFR), verified with an unprecedented set of large numerical simulations of driven, supersonic, self-gravitating, magneto-hydrodynamic (MHD) turbulence, where collapsing…

星系天体物理 · 物理学 2011-03-14 Paolo Padoan , AAke Nordlund

Supersonic turbulence in molecular clouds is a dominant agent that strongly affects the clouds' evolution and star formation activity. Turbulence may be initiated and maintained by a number of processes, acting at a wide range of physical…

星系天体物理 · 物理学 2014-11-20 C. M. Brunt , M. H. Heyer , M. -M. Mac Low

Magnetic turbulence is anisotropic as the directions of motion are constrained by the magnetic field. Such anisotropy can be observed in velocity centroids obtained from spectroscopic observations. We use magnetohydrodynamics (MHD)…

星系天体物理 · 物理学 2020-08-13 D. Hernández-Padilla , A. Esquivel , A. Lazarian , D. Pogosyan , D. Kandel , J. Cho

Faraday rotation of linearly polarized radio signals provides a very sensitive probe of fluctuations in the interstellar magnetic field and ionized gas density resulting from magnetohydrodynamic (MHD) turbulence. We used a set of…

星系天体物理 · 物理学 2015-06-03 Blakesley Burkhart , A. Lazarian , B. M. Gaensler

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…

天体物理学 · 物理学 2011-02-11 Liubin Pan , Paolo Padoan