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相关论文: Modeling mass functions of clumps formed during th…

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The statistical approach for derivation of the clump mass function (ClMF) developed by Donkov, Veltchev & Klessen is put to observational test through comparison with mass distributions of clumps from molecular emission and dust continuum…

星系天体物理 · 物理学 2015-06-15 Todor V. Veltchev , Sava Donkov , Ralf S. Klessen

We derive the mass function of condensations (clumps) which were formed through a turbulent cascade over a range of spatial scales $L\le20$ pc during early, predominantly turbulent evolution of a molecular cloud. The approach rests upon the…

太阳与恒星天体物理 · 物理学 2015-06-04 Sava Donkov , Todor V. Veltchev , Ralf S. Klessen

We develop a statistical approach for description of dense structures (cores) in molecular clouds that might be progenitors of stars. Our basic assumptions are a core mass-density relationship and a power-law density distribution of these…

太阳与恒星天体物理 · 物理学 2012-06-08 Sava Donkov , Orlin Stanchev , Todor V. Veltchev

We present a model for describing the general structure of molecular clouds (MCs) at early evolutionary stages in terms of their mass-size relationship. Sizes are defined through threshold levels at which equipartitions between…

星系天体物理 · 物理学 2016-04-26 Todor V. Veltchev , Sava Donkov , Ralf S. Klessen

We construct models of molecular clouds that are considered as ensembles of transient cores. Each core is assumed to develop in the background gas of the cloud, grow to high density and decay into the background. The chemistry in each core…

天体物理学 · 物理学 2009-11-13 R. T. Garrod , D. A. Williams , J. M. C. Rawlings

We introduce a model for the large-scale, global 3D structure of molecular clouds. Motivated by the morphological appearance of clouds in surface density maps, we model clouds as cylinders, with the aim of backing out information about the…

星系天体物理 · 物理学 2023-09-12 Nia Imara , John C. Forbes

I describe the scenario of molecular cloud (MC) evolution that has emerged over the past decade or so. MCs can start out as cold atomic clouds formed by compressive motions in the warm neutral medium (WNM) of galaxies. Such motions can be…

星系天体物理 · 物理学 2010-09-22 Enrique Vazquez-Semadeni

In this paper, we investigate the extent to which observations of molecular clouds can correctly identify and measure star-forming clumps. We produced a synthetic column density map and a synthetic spectral-line data cube from the simulated…

星系天体物理 · 物理学 2012-08-23 Rachel L. Ward , James Wadsley , Alison Sills , Nicolas Petitclerc

Giant molecular clouds (GMCs) are the primary reservoirs of cold, star-forming molecular gas in the Milky Way and similar galaxies, and thus any understanding of star formation must encompass a model for GMC formation, evolution, and…

I review the basic concepts for the spectrophotometric and chemical evolution of galaxies, contrast various approaches and discuss their respective advantages and shortcomings, both for the interpretation of nearby and high redshift…

天体物理学 · 物理学 2007-05-23 U. Fritze-v. Alvensleben

We review the progress that has been made in observing and analyzing molecular cloud structure in recent years. Structures are self-similar over a wide range of scales with similar power law indices independent of the star forming nature of…

天体物理学 · 物理学 2007-05-23 Jonathan P. Williams , Leo Blitz , Christopher F. McKee

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 are the principle stellar nurseries of our universe, keeping them in the focus of both observational and theoretical studies. From observations, some of the key properties of molecular clouds are well known but many…

星系天体物理 · 物理学 2017-09-20 M. Völschow , R. Banerjee , B. Körtgen

We describe an overall picture of galactic-scale star formation. Recent high-resolution magneto-hydrodynamical simulations of two-fluid dynamics with cooling/heating and thermal conduction have shown that the formation of molecular clouds…

星系天体物理 · 物理学 2015-07-29 Shu-ichiro Inutsuka , Tsuyoshi Inoue , Kazunari Iwasaki , Takashi Hosokawa

Observations reveal concentrations of molecular line emission on the sky, called ``clumps,'' in dense, star-forming molecular clouds. These clumps are believed to be the eventual sites of star formation. We study the three-dimensional…

天体物理学 · 物理学 2009-11-07 C. F. Gammie , Y. -T. Lin , J. M. Stone , E. C. Ostriker

We study the mass-density relationship n ~ m^x in molecular cloud condensations (clumps), considering various equipartition relations between their gravitational, kinetic, internal and magnetic energies. Clumps are described statistically,…

太阳与恒星天体物理 · 物理学 2015-05-20 Sava Donkov , Todor Veltchev , Ralf S. Klessen

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…

The isothermal gravitational collapse and fragmentation of a molecular cloud region and the subsequent formation of a protostellar cluster is investigated numerically. The clump mass spectrum which forms during the fragmentation phase can…

天体物理学 · 物理学 2007-05-23 Ralf Klessen , Andreas Burkert

The evolution of molecular clouds in galactic centres is thought to differ from that in galactic discs due to a significant influence of the external gravitational potential. We present a set of numerical simulations of molecular clouds…

We construct an analytic model for the mass distributions of superclusters and clusters in each supercluster. Our model is a modification of the Press-Schechter theory, and defines superclusters as the regions that have some overdensity…

天体物理学 · 物理学 2007-05-23 Masamune Oguri , Keitaro Takahashi , Kiyotomo Ichiki , Hiroshi Ohno
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