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Related papers: On the fragmentation boundary in magnetised self-g…

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It has recently been suggested that in the presence of driven turbulence discs may be much less stable against gravitational collapse than their non turbulent analogs, due to stochastic density fluctuations in turbulent flows. This mode of…

Earth and Planetary Astrophysics · Physics 2018-01-31 Ken Rice , Sergei Nayakshin

Geometrical frustration in magnetic materials often gives rise to exotic, low-temperature states of matter, like the ones observed in spin ices. Here we report the imaging of the magnetic states of a thermally-active artificial magnetic ice…

We study the ground state quantum fragmentation in a mixture of a polar condensate and a ferromagnetic condensate when subject to an external magnetic field. We pay more attentions to the polar condensate and find that it will be less…

Quantum Gases · Physics 2015-06-23 Jie Zhang , Xue Hou , Bin Chen , Yunbo Zhang

Using 2D smoothed particle hydrodynamics, we investigate the distribution of wait times between strong shocks in a turbulent, self-gravitating accretion disc. We show the resulting distributions do not depend strongly on the cooling time or…

Earth and Planetary Astrophysics · Physics 2015-11-18 Matthew D. Young , Cathie J. Clarke

Accretion disks that become gravitationally unstable can fragment into stellar or sub-stellar companions. The formation and survival of these fragments depends on the precarious balance between self-gravity, internal pressure, tidal…

Solar and Stellar Astrophysics · Physics 2015-05-28 Kaitlin M. Kratter , Ruth A. Murray-Clay

Massive stars disproportionately influence their surroundings. How they form has only started to become clear recently through radiation gas dynamical simulations. However, until now, no simulation has simultaneously included both magnetic…

Solar and Stellar Astrophysics · Physics 2015-03-17 Thomas Peters , Robi Banerjee , Ralf S. Klessen , Mordecai-Mark Mac Low

Self-gravitating discs are believed to play an important role in astrophysics in particular regarding the star and planet formation process. In this context, discs subject to an idealized cooling process, characterized by a cooling…

Astrophysics of Galaxies · Physics 2021-04-20 Noé Brucy , Patrick Hennebelle

Protoplanetary disks fragment due to gravitational instability when there is enough mass for self-gravitation, described by the Toomre parameter, and when heat can be lost at a rate comparable to the local dynamical timescale, described by…

Earth and Planetary Astrophysics · Physics 2015-12-08 Hans Baehr , Hubert Klahr

Recent cosmological hydrodynamic simulations have suggested that the first stars in the universe often form as binary or multiple systems. However, previous studies typically overlooked the potential influence of magnetic fields during this…

Astrophysics of Galaxies · Physics 2024-05-27 Kenji Eric Sadanari , Kazuyuki Omukai , Kazuyuki Sugimura , Tomoaki Matsumoto , Kengo Tomida

Low mass, self-gravitating accretion disks admit quasi-steady,`gravito-turbulent' states in which cooling balances turbulent viscous heating. However, numerical simulations show that gravito-turbulence cannot be sustained beyond dynamical…

Earth and Planetary Astrophysics · Physics 2016-06-22 Min-Kai Lin , Kaitlin M. Kratter

We carry out simulations of gravitationally unstable discs using a Smoothed Particle Hydrodynamics (SPH) code and a grid-based hydrodynamics code, FARGO, to understand the previous non-convergent results reported by Meru & Bate (2011a). We…

Earth and Planetary Astrophysics · Physics 2015-06-11 Farzana Meru , Matthew R. Bate

The planet-forming region of protoplanetary disks is cold, dense, and therefore weakly ionized. For this reason, magnetohydrodynamic (MHD) turbulence is thought to be mostly absent, and another mechanism has to be found to explain gas…

Earth and Planetary Astrophysics · Physics 2017-04-05 William Béthune , Geoffroy Lesur , Jonathan Ferreira

We carry out three dimensional radiation hydrodynamical simulations of gravitationally unstable discs using to explore the movement of mass in a disc following its fragmentation. Compared to a more quiescent state before it fragments, the…

Earth and Planetary Astrophysics · Physics 2013-05-31 Farzana Meru

We present first results of our simulations of magnetic fields in the formation of single and binary stars using a recently developed method for incorporating Magnetohydrodynamics (MHD) into the Smoothed Particle Hydrodynamics (SPH) method.…

Astrophysics · Physics 2009-06-23 Daniel J. Price , Matthew R. Bate

We study numerical convergence in local two-dimensional hydrodynamical simulations of self-gravitating accretion discs with a simple cooling law. It is well-known that there exists a steady gravito-turbulent state, in which cooling is…

Earth and Planetary Astrophysics · Physics 2015-06-03 Sijme-Jan Paardekooper

We study the numerical convergence of hydrodynamical simulations of self-gravitating accretion discs, in which a simple cooling law is balanced by shock heating. It is well-known that there exists a critical cooling time scale for which…

Earth and Planetary Astrophysics · Physics 2015-05-28 Sijme-Jan Paardekooper , Clement Baruteau , Farzana Meru

We use high resolution 3D SPH simulations to study the evolution of self-gravitating binary protoplanetary disks. Heating by shocks and cooling are included. We consider different orbital separations and masses of the disks and central…

Astrophysics · Physics 2009-11-10 Lucio Mayer , James Wadsley , Thomas Quinn , Joachim Stadel

We study numerically the collapse of non-rotating, self-gravitating, magnetized, singular isothermal toroids characterized by sound speed, $a$, and level of magnetic to thermal support, $H_0$. In qualitative agreement with previous…

Astrophysics · Physics 2009-11-10 A. Allen , F. H. Shu , Z. Y. Li

Magnetic fields spontaneously grow at unstable interfaces around hot-spot asymmetries during inertial confinement fusion implosions. Although difficult to measure, theoretical considerations and numerical simulations predict field strengths…

Plasma Physics · Physics 2022-07-20 James D. Sadler , Christopher A. Walsh , Ye Zhou , Hui Li

We study the initial development, structure and evolution of protoplanetary clumps formed in 3D resistive MHD simulations of self-gravitating disks. The magnetic field grows by means of the recently identified gravitational instability…

Earth and Planetary Astrophysics · Physics 2024-03-08 Noah Kubli , Lucio Mayer , Hongping Deng