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Related papers: Sub-structure formation in starless cores

200 papers

We perform three-dimensional shearing-box hydrodynamical simulations to explore the outcome of gravitational instability in the outer regions of neutrino-cooled disks such as those formed from the collapse of rotating massive stars…

High Energy Astrophysical Phenomena · Physics 2025-08-26 Yi-Xian Chen , Brian D. Metzger

We numerically investigate the evolution of compact high-velocity clouds (CHVCs) passing through a hot, tenuous gas representing the highly-ionized circumgalactic medium (CGM) by applying the adaptive-mesh refinement code FLASH. The model…

Astrophysics of Galaxies · Physics 2021-01-06 Bastian Sander , Gerhard Hensler

We study here the spontaneous clustering of a submonolayer of grains under horizontal circular shaking. The clustering of grains occurs when increasing the oscillation amplitude beyond a threshold. The dense area travels in a circular…

Soft Condensed Matter · Physics 2021-08-06 Song-Chuan Zhao , Thorsten Pöschel

Star formation occurs in hierarchical patterns in both space and time. Galaxies form large regions on the scale of the interstellar Jeans length and these large regions apparently fragment into giant molecular clouds and cloud cores in a…

Astrophysics of Galaxies · Physics 2015-05-27 Bruce G. Elmegreen

The properties of supersonic isothermal turbulence influence a variety of astrophysical phenomena, including the structure and evolution of star forming clouds. This work presents a simple model for the structure of dense regions in…

Astrophysics of Galaxies · Physics 2018-02-28 Brant Robertson , Peter Goldreich

We investigate the formation of protostellar clusters during the collapse of dense molecular cloud cores with a focus on the evolution of potential and kinetic energy, the degree of substructure, and the early phase of mass segregation. Our…

Solar and Stellar Astrophysics · Physics 2015-06-03 Philipp Girichidis , Christoph Federrath , Richard Allison , Robi Banerjee , Ralf Klessen

If the split, asymmetric molecular spectral line profiles that are seen in many starless cores are interpreted as indicative of global collapse or expansion of the core then one possible implication is that most starless cores have short…

Astrophysics · Physics 2009-11-11 Eric Keto , Avery Broderick , Charles J. Lada , Ramesh Narayan

The asymmetric molecular emission lines from dense cores reveal slow, inward motion in the clouds' outer regions. This motion is present both before and after the formation of a central star. Motivated by these observations, we revisit the…

Solar and Stellar Astrophysics · Physics 2015-06-05 Paul A. Dalba , Steven W. Stahler

We study the formation, evolution and collapse of dense cores by tracking structures in a magnetohydrodynamic simulation of a star-forming cloud. We identify cores using the dendrogram algorithm and utilize machine learning techniques,…

We simulate the propagation and dissipation of tidally induced nonlinear gravity waves in the cores of solar-type stars. We perform hydrodynamical simulations of a previously developed Boussinesq model using a spectral-element code to study…

Solar and Stellar Astrophysics · Physics 2023-03-08 Zhao Guo , Gordon I. Ogilvie , Adrian J. Barker

Abridged. A large fraction of stars are found in binary systems. It is therefore important for our understanding of the star formation process, to investigate the fragmentation of dense molecular cores. We study the influence of the…

Astrophysics · Physics 2009-11-13 P. Hennebelle , R. Teyssier

We study the photoevaporation of Jeans-unstable molecular clumps by isotropic FUV (6 eV $< {\rm h}\nu$ < 13.6 eV) radiation, through 3D radiative transfer hydrodynamical simulations implementing a non-equilibrium chemical network that…

Astrophysics of Galaxies · Physics 2019-07-25 D. Decataldo , A. Pallottini , A. Ferrara , L. Vallini , S. Gallerani

Thermal instability (TI) is a trigger mechanism, which can explain the formation of small condensations through some regions of the interstellar clouds. The instability criterion for flat geometry approximations has been investigated in…

Astrophysics of Galaxies · Physics 2024-12-24 Mohsen Nejad-Asghar

Context. Turbulence is a key component of molecular cloud structure. It is usually described by a cascade of energy down to the dissipation scale. The power spectrum for subsonic incompressible turbulence is $k^{-5/3}$, while for supersonic…

We study the gravitational instability of an isothermal gaseous slab formed by cloud-cloud collision and compression at the cloud interface. The compressed gaseous slab rotates and has velocity shear except when the collision is not exactly…

Astrophysics · Physics 2007-05-23 Masatoshi Usami , Tomoyuki Hanawa , Mitsuaki Fujimoto

Mass functions of starless dense cores (CMFs) may arise from contraction and dispersal of core-forming filaments. In an illustrative model, a filament contracts radially by self-gravity, increasing the mass of its cores. During this…

Astrophysics of Galaxies · Physics 2015-06-12 Philip C. Myers

Inspired by Barnard 68, a Bok globule, that undergoes stable oscillations, we perform multi-phase hydrodynamic simulations to analyze the stability of Bok globules. We show that a high-density soft molecular core, with an adiabatic index…

Solar and Stellar Astrophysics · Physics 2017-09-27 Ui-Han Zhang , Hsi-Yu Schive , Tzihong Chiueh

The thermal and chemical evolution of star-forming clouds is studied for different gas metallicities, Z, using the model of Omukai (2000), updated to include deuterium chemistry and the effects of cosmic microwave background (CMB)…

Astrophysics · Physics 2009-11-10 K. Omukai , T. Tsuribe , R. Schneider , A. Ferrara

We employ the three-dimensional magnetohydrodynamic simulation including ambipolar diffusion to study the gravitationally-driven fragmentation of subcritical molecular clouds, in which the gravitational fragmentation is stabilized as long…

Solar and Stellar Astrophysics · Physics 2015-05-20 Takahiro Kudoh , Shantanu Basu

We investigate the stability of bounded self-gravitating systems in the canonical ensemble by using a thermodynamical approach. Our study extends the earlier work of Padmanabhan [Astrophys. J. Supp. 71, 651 (1989)] in the microcanonical…

Astrophysics · Physics 2009-11-06 P. -H. Chavanis