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Related papers: Structure and Stability of Prestellar Cores

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Motivated by recent observational searches of sub-structure in starless molecular cloud cores, we investigate the evolution of density perturbations on scales smaller than the Jeans length embedded in contracting isothermal clouds, adopting…

Solar and Stellar Astrophysics · Physics 2017-12-20 C. Toci , D. Galli , A. Verdini , L. Del Zanna , S. Landi

We compute numerical simulations of spherical collapse triggered by a slow increase in external pressure. We compare isothermal models to models including cooling with a simple but self-consistent treatment of the coupling between gas,…

Astrophysics · Physics 2009-11-11 P. Lesaffre , A. Belloche , J. -P. Chieze , P. Andre

Magnetic fields are dynamically important in the diffuse interstellar medium. Understanding how gravitationally bound, star-forming clouds form requires modeling of the fields in a self-consistent, supernova-driven, turbulent, magnetized,…

Astrophysics of Galaxies · Physics 2022-02-16 Juan C. Ibáñez-Mejía , Mordecai-Mark Mac Low , Ralf S. Klessen

We performed sub-parsec (~0.06pc) scale simulations of two idealised molecular clouds with different masses undergoing a collision. Gas clumps with density greater than 1e-20 g/cm3 (0.3e4 cm-3) were identified as pre-stellar cores and…

Astrophysics of Galaxies · Physics 2015-06-22 Ken Takahira , Elizabeth J. Tasker , Asao Habe

The configuration and evolution of the magnetic field in star-forming cores are investigated in order to directly compare simulations and observations. We prepare four different initial clouds having different magnetic field strengths and…

Solar and Stellar Astrophysics · Physics 2015-06-11 Akimasa Kataoka , Masahiro N. Machida , Kohji Tomisaka

Filamentary molecular clouds are omnipresent in the cold interstellar medium. Observational evidences show that the non-isothermal equations of state describe the filaments properties better than the isothermal one. In this paper we use the…

Astrophysics of Galaxies · Physics 2021-02-04 Mohammad Mahdi Motiei , Mohammad Hosseinirad , Shahram Abbassi

To understand the formation of stars from clouds of molecular gas, one essentially needs to know two things: What gas collapses, and how long it takes to do so. We address these questions by embedding pseudo-Lagrangian tracer particles in…

Astrophysics of Galaxies · Physics 2022-10-12 David C. Collins , Dan K. Le , Luz L. Jimenez Vela

Recently, a subset of starless cores whose thermal Jeans mass is apparently overwhelmed by the mass of the core has been identified, e.g., the core {\small L183}. In literature, massive cores such as this one are often referred to as…

Astrophysics of Galaxies · Physics 2013-01-03 S. Anathpindika , James Di Francesco

The influence of rotation and magnetic fields on the physical properties of isothermal gas clouds is discussed. The presence of rotation and/or magnetic fields results in an increase of the critical cloud mass with respect to gravitational…

Astrophysics · Physics 2009-11-07 B. Vollmer , W. J. Duschl

Planet-forming disks are fundamental objects thought to be inherited from large scale rotation, through the conservation of angular momentum during the collapse of a prestellar dense core. We investigate the possibility for a protostellar…

Astrophysics of Galaxies · Physics 2020-03-25 Antoine Verliat , Patrick Hennebelle , Anaëlle J. Maury , Mathilde Gaudel

We examined the gravitational contraction of isothermal molecular cloud cores with slow rotation by means of two-dimensional numerical simulations. Applying a sink-cell method, we followed the evolution of the cloud cores up to the stages…

Astrophysics · Physics 2009-10-31 Fumitaka Nakamura

Context. Low-mass star-forming cores differ from their surrounding molecular cloud in turbulence, shape, and density structure. Aims. We aim to understand how dense cores form out of the less dense cloud material by studying the connection…

Astrophysics of Galaxies · Physics 2015-05-28 A. Hacar , M. Tafalla

The thermal and chemical evolution of gravitationally collapsing protostellar clouds is investigated, focusing attention on their dependence on metallicity. Calculations are carried out for a range of metallicities spanning the local…

Astrophysics · Physics 2009-10-31 Kazuyuki Omukai

Self-similar solutions provide good descriptions for the gravitational collapse of spherical clouds or stars when the gas obeys a polytropic equation of state, $p=K\rho^\gamma$ (with $\gamma\le 4/3$). We study the behaviors of nonradial…

Astrophysics · Physics 2009-10-31 Dong Lai

This work explores the morphology and dynamical properties of cores within rich superclusters, highlighting their role as transitional structures in the large-scale structure of the Universe. Using projected and radial velocity…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-18 J. M. Zúñiga , C. A. Caretta , H. Andernach

Three dimensional (3D) magnetic field information on molecular clouds and cores is important for revealing their kinematical stability (magnetic support) against gravity which is fundamental for studying the initial conditions of star…

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…

Astrophysics of Galaxies · Physics 2010-09-22 Enrique Vazquez-Semadeni

During the last two decades, the focus of star formation research has shifted from understanding the collapse of a single dense core into a star to studying the formation hundreds to thousands of stars in molecular clouds. In this chapter,…

Astrophysics · Physics 2008-01-04 S. T. Megeath , Zhi-Yun Li , Aake Nordlund

Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud…

Astrophysics · Physics 2007-05-23 Ralf Klessen

Dense cores inherit turbulent motions from the interstellar medium in which they form. As a tool for comparison to both simulations and observations, it is valuable to construct theoretical core models that can relate their internal density…

Astrophysics of Galaxies · Physics 2025-06-05 Sanghyuk Moon , Eve C. Ostriker
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