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Related papers: Brown dwarf formation by binary disruption

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We suggest that low-mass hydrogen-burning stars like the Sun should sometimes form with massive extended discs; and we show, by means of radiation hydrodynamic simulations, that the outer parts of such discs (R>100 AU) are likely to…

Astrophysics · Physics 2009-11-13 Dimitris Stamatellos , David Hubber , Anthony Whitworth

The formation of brown dwarfs (BDs) poses a key challenge to star formation theory. The observed dearth of nearby ($\leq 5$ AU) brown dwarf companions to solar-mass stars, known as the brown dwarf desert, as well as the tendency for…

Solar and Stellar Astrophysics · Physics 2015-03-20 Peter H. Jumper , Robert T. Fisher

We present results from the first hydrodynamical star formation calculation to demonstrate that brown dwarfs are a natural and frequent product of the collapse and fragmentation of a turbulent molecular cloud. The brown dwarfs form via the…

Astrophysics · Physics 2009-11-07 Matthew R. Bate , Ian A. Bonnell , Volker Bromm

The observational properties of brown dwarfs pose challenges to the theory of star formation. Because their mass is much smaller than the typical Jeans mass of interstellar clouds, brown dwarfs are most likely formed through secondary…

Astrophysics · Physics 2007-05-23 Ing-Guey Jiang , G. Laughlin , D. N. C. Lin

We review four mechanisms for forming brown dwarfs: (i) turbulent fragmentation (producing very low-mass prestellar cores); (ii) gravitational instabilities in discs; (iii) dynamical ejection of stellar embryos from their placental cores;…

Astrophysics · Physics 2009-11-11 A. P. Whitworth , S. P. Goodwin

The observational properties of brown dwarfs pose challenges to the theory of star formation. Because their mass is much smaller than the typical Jeans mass of interstellar clouds, brown dwarfs are most likely formed through secondary…

Astrophysics · Physics 2009-11-10 Ing-Guey Jiang , G. Laughlin , D. N. C. Lin

We review the current state of observational work on the formation of brown dwarfs, focusing on their initial mass function, velocity and spatial distributions at birth, multiplicity, accretion, and circumstellar disks. The available…

We suggest that a high proportion of brown dwarfs are formed by gravitational fragmentation of massive, extended discs around Sun-like stars. We argue that such discs should arise frequently, but should be observed infrequently, precisely…

Astrophysics · Physics 2009-11-13 Dimitris Stamatellos , Anthony P. Whitworth

We suggest that a high proportion of brown dwarfs are formed by gravitational fragmentation of massive extended discs around Sun-like stars. Such discs should arise frequently, but should be observed infrequently, precisely because they…

Astrophysics · Physics 2009-11-13 Dimitris Stamatellos , Anthony P. Whitworth

We review five mechanisms for forming brown dwarfs: (i) turbulent fragmentation of molecular clouds, producing very low-mass prestellar cores by shock compression; (ii) collapse and fragmentation of more massive prestellar cores; (iii) disc…

Astrophysics · Physics 2007-05-23 Anthony Whitworth , Matthew R. Bate , Aake Nordlund , Bo Reipurth , Hans Zinnecker

Several mechanisms have been proposed for the formation of brown dwarfs, but there is as yet no consensus as to which -- if any -- are operative in nature. Any theory of brown dwarf formation must explain the observed statistics of brown…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. Kaplan , D. Stamatellos , A. P. Whitworth

A large fraction of the observed brown dwarfs may form by gravitational fragmentation of unstable discs. This model reproduces the brown dwarf desert, and provides an explanation the existence of planetary-mass objects and for the binary…

Astrophysics of Galaxies · Physics 2015-05-14 Dimitris Stamatellos , Anthony Whitworth

The formation of brown dwarfs via encounters between proto-stars has been confirmed with high-resolution numerical simulations with a restricted treatment of the thermal conditions. The new results indicate that young brown dwarfs (BDs)…

Astrophysics · Physics 2010-11-11 Sijing Shen , James Wadsley

We conjecture that brown dwarfs are substellar objects because they have been ejected from small newborn multiple systems which have decayed in dynamical interactions. In this view, brown dwarfs are stellar embryos for which the star…

Astrophysics · Physics 2009-11-06 Bo Reipurth , Cathie Clarke

The formation of brown dwarfs (BDs) due to the fragmentation of proto-stellar disks undergoing pairwise encounters was investigated. High resolution allowed the use of realistic initial disk models where both the vertical structure and the…

Solar and Stellar Astrophysics · Physics 2015-05-14 Sijing Shen , James Wadsley , Tristen Hayfield , Nicholas Ellens

Most stars are born in clusters and the resulting gravitational interactions between cluster members may significantly affect the evolution of circumstellar discs and therefore the formation of planets and brown dwarfs. Recent findings…

Solar and Stellar Astrophysics · Physics 2010-06-18 Ingo Thies , Pavel Kroupa , Simon P. Goodwin , Dimitrios Stamatellos , Anthony P. Whitworth

We show that the dearth of brown dwarfs in short-period orbits around Solar-mass stars - the brown dwarf desert - can be understood as a consequence of inward migration within an evolving protoplanetary disc. Brown dwarf secondaries forming…

Astrophysics · Physics 2009-11-07 Philip J. Armitage , Ian A. Bonnell

A large fraction of brown dwarfs and low-mass stars may form by gravitational fragmentation of relatively massive (a few 0.1 Msun), extended (a few hundred AU) discs around Sun-like stars. We present an ensemble of radiative hydrodynamic…

Astrophysics of Galaxies · Physics 2015-05-20 Dimitris Stamatellos , Anthony Whitworth

Our first aim is to calculate the minimum mass for Primary Fragmentation in a variety of potential star-formation scenarios, i.e. (i) hierarchical fragmentation of a 3-D medium; (ii) one-shot, 2-D fragmentation of a shock-compressed layer;…

Astrophysics · Physics 2009-11-11 A. P. Whitworth , D. Stamatellos

Theory and simulations suggest that it is possible to form low-mass hydrogen-burning stars, brown dwarfs and planetary-mass objects via disc fragmentation. As disc fragmentation results in the formation of several bodies at comparable…

Solar and Stellar Astrophysics · Physics 2015-06-11 Yun Li , M. B. N. Kouwenhoven , D. Stamatellos , S. P. Goodwin
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