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Related papers: Protostellar Jets and Outflows in low-mass star fo…

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We explore a new, efficient mechanism that can power toroidally magnetized jets up to two to three times their original terminal velocity after they enter a self-similar phase of magnetic acceleration. Underneath the elongated outflow lobe…

Solar and Stellar Astrophysics · Physics 2023-03-02 Hsien Shang , Ruben Krasnopolsky , Chun-Fan Liu

We discuss the transport of angular momentum induced by tidal effects in a disk surrounding a star in a pre-main sequence binary system. We consider the effect of both density and bending waves. Although tidal effects are important for…

Astrophysics · Physics 2007-05-23 Caroline E. J. M. L. J. Terquem

Dust growth and its associated dynamics play key roles in the first phase of planet formation in young stellar objects (YSOs). Observations have detected signs of dust growth in very young protoplanetary disks. Furthermore, signs of planet…

Solar and Stellar Astrophysics · Physics 2021-10-27 Yusuke Tsukamoto , Masahiro N. Machida , Shu-ichiro Inutsuka

We investigate outflows driven by a giant protoplanet using three-dimensional MHD nested grid simulations. We consider a local region around the protoplanet in the protoplanetary disk, and calculate three models: (a) unmagnetized disk…

Astrophysics · Physics 2011-02-11 Masahiro N. Machida , Shu-ichiro Inutsuka , Tomoaki Matsumoto

Magnetic diffusion plays a vital role in star formation. We trace its influence from interstellar cloud scales down to star-disk scales. On both scales, we find that magnetic diffusion can be significantly enhanced by the buildup of strong…

Solar and Stellar Astrophysics · Physics 2013-08-19 Shantanu Basu , Wolf B. Dapp

Using high resolution, fully cosmological smoothed particle hydro-dynamical simulations of dwarf galaxies in a Lambda cold dark matter Universe, we show how baryons attain a final angular momentum distribution which allows pure disc…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 C. B. Brook , F. Governato , R. Roskar , G. Stinson , A. Brooks , J. Wadsley , T. Quinn , B. K. Gibson , O. Snaith , K. Pilkington , E. House , A. Pontzen

The accretion phase of star formation is investigated in magnetically-dominated clouds that have an initial subcritical mass-to-flux ratio. We employ nonideal magnetohydrodynamic simulations that include ambipolar diffusion and ohmic…

Solar and Stellar Astrophysics · Physics 2020-03-18 Masahiro N. Machida , Shantanu Basu

Angular momentum plays a crucial role in the formation of stars and planets. It has long been noticed that parcels of gas in molecular clouds need to reduce their specific angular momentum by 6 to 7 orders of magnitude to participate in the…

Astrophysics of Galaxies · Physics 2015-06-15 Arnaud Belloche

The slow rotation of some young stars and the extreme rotation periods of some Ap stars have so far defied explanation. The absence of sufficiently efficient braking mechanisms for newly formed stars points to the star formation process…

Solar and Stellar Astrophysics · Physics 2018-10-23 H. C. Spruit

Observations of jets from young stellar objects reveal the asymmetric outflows from some sources. A large set of $2.5$D MHD simulations has been carried out for axisymmetric viscous/diffusive disc accretion to rotating magnetized stars for…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Sergei Dyda , Richard V. E. Lovelace , Galina V. Ustyugova , Patrick S. Lii , Marina M. Romanova , Alexander V. Koldoba

We calculate the evolution of a star-forming cloud core using a three-dimensional resistive magnetohydrodynamics simulation, treating dust grains as Lagrangian particles, to investigate the dust motion in the early star formation stage. We…

Solar and Stellar Astrophysics · Physics 2022-12-14 Shunta Koga , Masahiro N. Machida

An axisymmetric model of a cool, dynamo-active accretion disc is applied to protostellar discs. Thermally and magnetically driven outflows develop that are not collimated within 0.1 AU. In the presence of a central magnetic field from the…

Astrophysics · Physics 2009-11-10 Brigitta von Rekowski , Axel Brandenburg , Wolfgang Dobler , Anvar Shukurov

We study protoplanetary disc evolution assuming that angular momentum transport is driven by gravitational instability at large radii, and magnetohydrodynamic (MHD) turbulence in the hot inner regions. At radii of the order of 1 AU such…

Astrophysics · Physics 2009-11-06 Philip J. Armitage , Mario Livio , J. E. Pringle

We present the first-ever simulations of non-ideal magnetohydrodynamical (MHD) stellar magnetospheric winds coupled with disc-driven jets where the resistive and viscous accretion disc is self-consistently described. These innovative MHD…

Astrophysics · Physics 2011-02-19 Z. Meliani , F. Casse , C. Sauty

Using numerical hydrodynamics simulations we studied the gravitational collapse of pre-stellar cores of sub-solar mass embedded into a low-density external environment. Four models with different magnitude and direction of rotation of the…

Solar and Stellar Astrophysics · Physics 2015-06-23 Eduard I. Vorobyov , D. N. C. Lin , Manuel Guedel

Massive stars can during their evolution reach the phase of critical (or very rapid, near-critical) rotation when further increase in rotation rate is no longer kinematically allowed. The mass ejection and angular momentum outward transport…

Solar and Stellar Astrophysics · Physics 2024-02-28 Petr Kurfürst

In this work the most spectacular phenomena occurring during the formation of a star are briefly reviewed: accretion through a rotating disc of matter and outflow through the poles of the new stellar object. Magnetic fields have been…

Astrophysics · Physics 2007-05-23 Michele Pestalozzi

Protostellar jets are an important agent of star formation feedback, tightly connected with the mass-accretion process. The history of jet formation and mass-ejection provides constraints on the mass accretion history and the nature of the…

We present Atacama Large Millimeter/submillimeter Array observations of the $\sim$10 kAU environment surrounding 21 protostars in the Orion A molecular cloud tracing outflows. Our sample is composed of Class 0 to flat-spectrum protostars,…

The transport of angular momentum is capital during the formation of low-mass stars; too little removal and rotation ensures stellar densities are never reached, too much and the absence of rotation means no protoplanetary disks can form.…

Solar and Stellar Astrophysics · Physics 2018-07-04 Neil Vaytet , Benoît Commerçon , Jacques Masson , Matthias González , Gilles Chabrier