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This paper considers the phenomenon of deep core collapse in collisional stellar systems, with stars of equal mass. The collapse takes place on some multiple, $\xi ^{-1}$, of the central relaxation time, and produces a density profile in…

Astrophysics · Physics 2008-11-26 Holger Baumgardt , Douglas C. Heggie , Piet Hut , Junichiro Makino

The observed rapid onset of star formation in molecular clouds requires rapid formation of dense fragments which can collapse individually before being overtaken by global gravitationally-driven flows. Many previous investigations have…

Astrophysics · Physics 2009-11-13 F. Heitsch , L. Hartmann , A. Burkert , ;

It has recently been suggested that the typical separation between cores in molecular clouds dominated by turbulence is determined by the sonic scale, the size scale at which the turbulent velocity dispersion equals the sound speed. In this…

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 present preliminary numerical evidence that the physical conditions in high-mass star forming regions can arise from global gravitational infall, with the velocity dispersions being caused primarily by infall motions rather than random…

A fundamental assumption in our understanding of disks is that when the Toomre Q>>1, the disk is stable against fragmentation into self-gravitating objects (and so cannot form planets via direct collapse). But if disks are turbulent, this…

Earth and Planetary Astrophysics · Physics 2014-11-13 Philip F. Hopkins , Jessie L. Christiansen

Stellar feedback in the form of radiation pressure and magnetically-driven collimated outflows may limit the maximum mass that a star can achieve and affect the star-formation efficiency of massive pre-stellar cores. Here we present a…

Solar and Stellar Astrophysics · Physics 2020-07-29 Anna L. Rosen , Mark R. Krumholz

The morphology and kinematics of molecular clouds (MCs) are best explained as the consequence of super--sonic turbulence. Super--sonic turbulence fragments MCs into dense sheets, filaments and cores and large low density ``voids'', via the…

Astrophysics · Physics 2008-11-26 Paolo Padoan , AAke Nordlund

We simulate the formation and collapse of prestellar cores at few-AU resolution in a set of radiation-magneto-hydrodynamic simulations of giant molecular clouds (GMCs) using the grid-based code RAMSES-RT. We adopt, for the first time to our…

Astrophysics of Galaxies · Physics 2023-05-10 Chong-Chong He , Massimo Ricotti

[abridged] We investigate the velocity structure of protostellar cores that result from non-magnetic numerical models of the gravoturbulent fragmentation of molecular cloud material. A large fraction of the cores analyzed are ``quiescent'',…

We present idealized numerical simulations of prestellar gravitational collapse of a moderate initial filamentary perturbation with an additional central ellipsoidal enhancement (a core) considering a uniform, and a stratified background,…

Astrophysics of Galaxies · Physics 2022-01-12 Raúl Naranjo-Romero , Enrique Vázquez-Semadeni , Robert M. Loughnane

The formation of circumstellar discs is a critical step in the formation of stars and planets. Magnetic fields can strongly affect the evolution of angular momentum during prestellar core collapse, potentially leading to the failure of…

Astrophysics of Galaxies · Physics 2024-03-18 Chong-Chong He , Massimo Ricotti

Supersonic turbulence fragments the interstellar medium into dense sheets, filaments, cores and large low density voids. The turbulence is driven on large scales, probably predominantly by supernovae. The scaling properties of supersonic…

Astrophysics · Physics 2007-05-23 Aake Nordlund , Paolo Padoan

Improving our understanding of the earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We discuss recent advances made in this area thanks to detailed…

Astrophysics · Physics 2007-05-23 Philippe Andre , Arnaud Belloche , Patrick Hennebelle , Derek Ward-Thompson

Sheet-like clouds are common in turbulent gas and perhaps form via collisions between turbulent gas flows. Having examined the evolution of an isothermal shocked slab in an earlier contribution, in this work we follow the evolution of a…

Astrophysics of Galaxies · Physics 2015-06-23 S. Anathpindika

We report results from numerical simulations of star formation in the early universe that focus on the role of subsonic turbulence, and investigate whether it can induce fragmentation of the gas. We find that dense primordial gas is highly…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-19 S. C. O. Glover , P. C. Clark , R. S. Klessen , V. Bromm

The burst mode of accretion in massive star formation is a scenario linking the initial gravitational collapse of parent pre-stellar cores to the properties of their gravitationally unstable discs and of their accretion-driven bursts. In…

Solar and Stellar Astrophysics · Physics 2022-10-26 D. M. -A. Meyer , E. I. Vorobyov , V. G. Elbakyan , S. Kraus , S. -Y. Liu , S. Nayakshin , A. M. Sobolev

Using hydrodynamic simulations we investigate the rotational properties and angular momentum evolution of prestellar and protostellar cores formed from gravoturbulent fragmentation of interstellar gas clouds. We find the specific angular…

Astrophysics · Physics 2009-11-10 A. -K. Jappsen , R. S. Klessen

Observations of prestellar cores in star-forming filaments show two distinct morphologies. While molecular line measurements often show broad cores, submillimeter continuum observations predominantly display pinched cores compared to the…

Astrophysics of Galaxies · Physics 2018-08-15 Stefan Heigl , Matthias Gritschneder , Andreas Burkert

We investigate the physical properties of dense cores formed in turbulent, magnetized, parsec-scale clumps of molecular clouds, using three-dimensional numerical simulations that include protostellar outflow feedback. The dense cores are…

Solar and Stellar Astrophysics · Physics 2015-05-28 Fumitaka Nakamura , Zhi-Yun Li