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Related papers: Polytropic models of filamentary interstellar clou…

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We investigate the gas velocity dispersions of a sample of filaments recently detected as part of the Herschel Gould Belt Survey in the IC5146, Aquila, and Polaris interstellar clouds. To measure these velocity dispersions, we use 13CO,…

Solar and Stellar Astrophysics · Physics 2015-06-15 Doris Arzoumanian , Philippe André , Nicolas Peretto , Vera Konyves

The strengths of magnetic fields in interstellar gas clouds are obtained through observations of the circular polarization of spectral line radiation. Irregularities in this magnetic field may be present due to turbulence, waves or perhaps…

Astrophysics · Physics 2009-10-31 W. D. Watson , D. S. Wiebe , R. M. Crutcher

In an extension of Fischera & Martin (2012a) and Heitsch (2013), two aspects of the evolution of externally pressurized, hydrostatic filaments are discussed. (a) The free-fall accretion of gas onto such a filament will lead to filament…

Astrophysics of Galaxies · Physics 2015-06-17 Fabian Heitsch

I review recent results derived from numerical simulations of the turbulent interstellar medium (ISM), in particular concerning the nature and formation of turbulent clouds, methods for comparing the structure in simulations and…

Astrophysics · Physics 2018-03-28 Enrique Vázquez-Semadeni

[Abridged] The interstellar medium is observed to be organised in filamentary structures, as well as neutral (HI) and ionized (HII) bubbles. The expanding nature of these bubbles makes them shape their surroundings and possibly play a role…

Observations of the cores of nearby galaxy clusters show H$\alpha$ and molecular emission line filaments. We argue that these are the result of {\em local} thermal instability in a {\em globally} stable galaxy cluster core. We present…

Astrophysics of Galaxies · Physics 2015-05-18 Prateek Sharma , Ian J. Parrish , Eliot Quataert

The interstellar medium (ISM) is a turbulent, highly structured multi-phase medium. State-of-the-art cosmological simulations of the formation of galactic discs usually lack the resolution to accurately resolve those multi-phase structures.…

Astrophysics of Galaxies · Physics 2022-04-13 Tobias Buck , Christoph Pfrommer , Philipp Girichidis , Bogdan Corobean

We examine the idea that diffuse and giant molecular clouds and their substructure form as density fluctuations induced by large scale interstellar turbulence. We do this by investigating the topology of various fields in realistic…

Astrophysics · Physics 2009-10-30 Javier Ballesteros-Paredes , Enrique Vazquez-Semadeni , John Scalo

This paper is an investigation of the stability of some ideal stars. It is in- tended as a study in General Relativity, with emphasis on the coupling to matter, eventually aimed at a better understanding of very strong gravitational fields…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian Fronsdal

{Filaments are ubiquitous in the interstellar medium as recently emphasized by Herschel, yet their physical origin remains elusive} {It is therefore important to understand the physics of molecular clouds to investigate how filaments form…

Astrophysics of Galaxies · Physics 2015-06-16 Patrick Hennebelle

Polytropes have gained renewed interest because they account for several seemingly-disconnected observational properties of galaxies. Here we study if polytropes are also able to explain the stellar mass distribution within galaxies. We…

Astrophysics of Galaxies · Physics 2021-11-17 J. Sanchez Almeida , I. Trujillo , A. R. Plastino

The interstellar medium of galaxies is governed by supersonic turbulence, which likely controls the star formation rate (SFR) and the initial mass function (IMF). Interstellar turbulence is non-universal, with a wide range of Mach numbers,…

Astrophysics of Galaxies · Physics 2015-03-13 Christoph Federrath , Supratik Banerjee

We perform ideal MHD high resolution AMR simulations with driven turbulence and self-gravity and find that long filamentary molecular clouds are formed at the converging locations of large-scale turbulence flows and the filaments are…

Astrophysics of Galaxies · Physics 2019-04-10 Pak Shing Li , Richard I. Klein

We have previously explored cylindrical packings of disks and their relation to sphere packings. Here we extend the analytical treatment of disk packings, analysing the rules for phyllotactic indices of related structures and the variation…

Soft Condensed Matter · Physics 2015-06-18 Adil Mughal , Denis Weaire

We report results from the analysis of 21 nearby galaxy clusters, 11 with cooling flow (CF) and 10 without cooling flow, observed with BeppoSAX. The temperature profiles of both CF and non-CF systems are characterized by an isothermal core…

Astrophysics · Physics 2009-11-07 Sabrina De Grandi , Silvano Molendi

In recent years, there were studies on the omnipresence and structures of filaments in star-forming regions, and the role of their fragmentation in the process of star formation. However, only a few studies analysed the evolution of…

Astrophysics of Galaxies · Physics 2018-06-07 Roxana-Adela Chira

Polytropic stars are useful tools for learning about stellar structure without the complexity of comprehensive stellar models. These models rely on a certain power-law correlation between the star's pressure and density. This paper proposes…

General Relativity and Quantum Cosmology · Physics 2024-07-19 Akashdip Karmakar , Ujjal Debnath , Pramit Rej

The interstellar medium is characterised by an intricate filamentary network which exhibits complex structures. These show a variety of different shapes (e.g. junctions, rings, etc.) deviating strongly from the usually assumed cylindrical…

Astrophysics of Galaxies · Physics 2021-07-14 Elena Hoemann , Stefan Heigl , Andreas Burkert

We provide a first look at the results of the Herschel Gould Belt survey toward the IC5146 molecular cloud and present a preliminary analysis of the filamentary structure in this region. The column density map, derived from our 70-500…

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…