2020/09/02 by Pierre Marchand, Marchand, Pierre, Kengo Tomida +7
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2009.01268
openalex publication_date 2020/09/02 · openalex created_date 2022/07/23 · openalex updated_date 2026/07/28
Through the magnetic braking and the launching of protostellar outflows,\nmagnetic fields play a major role in the regulation of angular momentum in star\nformation, which directly impacts the formation and evolution of protoplanetary\ndisks and binary systems. The aim of this paper is to quantify those phenomena\nin the presence of non-ideal magnetohydrodynamics effects, namely the Ohmic and\nambipola r diffusion. We perform three-dimensional simulations of protostellar\ncollapses varying the mass of the prestellar dense core, the thermal support\n(the \α ratio) and the dust grain size-distribu tion. The mass mostly\ninfluences the magnetic braking in the pseudo-disk, while the thermal support\nimpacts the accretion rate and hence the properties of the disk. Removing the\ngrains smaller than 0. 1 \μm in the Mathis, Rumpl, Nordsieck (MRN)\ndistribution enhances the ambipolar diffusion coefficient. Similarly to\nprevious studies, we find that this change in the distribution reduces the\nmagnet ic braking with an impact on the disk. The outflow is also significantly\nweakened. In either case, the magnetic braking largely dominates the outflow as\na process to remove the angular momentum from t he disk. Finally, we report a\nlarge ionic precursor to the outflow with velocities of several km s-1,\nwhich may be observable.\n