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Through the magnetic braking and the launching of protostellar outflows, magnetic fields play a major role in the regulation of angular momentum in star formation, which directly impacts the formation and evolution of protoplanetary disks…

Solar and Stellar Astrophysics · Physics 2020-09-04 Pierre Marchand , Kengo Tomida , Kei Tanaka , Benoît Commerçon , Gilles Chabrier

The determination of the fractional electron abundance, Xe, in protostellar cores relies on observations of molecules, such as DCO+, H13CO+ and CO, and on chemical models to interpret their abundance. Studies of protostellar cores have…

Astrophysics · Physics 2009-11-10 Paolo Padoan , Karen Willacy , William Langer , Mika Juvela

The formation of protoplanetary discs during the collapse of molecular dense cores is significantly influenced by angular momentum transport, notably by the magnetic torque. In turn, the evolution of the magnetic field is determined by…

Astrophysics of Galaxies · Physics 2017-02-01 Patrick Hennebelle , Benoit Commercon , Gilles Chabrier , Pierre Marchand

Aims and Methods. Accretion bursts triggered by the magnetorotational instability (MRI) in the innermost disk regions were studied for protoplanetary gas-dust disks formed from prestellar cores of various mass $M_{\rm core}$ and…

Solar and Stellar Astrophysics · Physics 2020-12-09 Eduard Vorobyov , Sergey Khaibrakhmanov , Shantanu Basu , Marc Audard

The energy density of energetic protons, U_p, in several nearby starburst nuclei (SBNs) has been directly deduced from gamma-ray measurements of the radiative decay of neutral pions produced in interactions with ambient protons. Lack of…

High Energy Astrophysical Phenomena · Physics 2014-09-05 Massimo Persic , Yoel Rephaeli

Magnetic fields are usually considered dynamically important in star formation when the dimensionless mass-to-flux ratio is close to, or less than, unity (lambda<~1). We show that, in disk formation, the requirement is far less stringent.…

Astrophysics · Physics 2009-11-13 Richard R. Mellon , Zhi-Yun Li

We calculate the physical structure of protoplanetary disks by evaluating the gas density and temperature self-consistently and solving separately for the dust temperature. The effect of grain growth is taken into account by assuming a…

Astrophysics · Physics 2009-11-11 Yuri Aikawa , Hideko Nomura

We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionised, stratified accretion discs. The magnetic field is initially vertical and dust grains are assumed to have settled towards…

Astrophysics · Physics 2009-11-10 Raquel Salmeron , Mark Wardle

Short-period super-Earth-sized planets are common. Explaining how they form near their present orbits requires understanding the structure of the inner regions of protoplanetary discs. Previous studies have argued that the hot inner…

Earth and Planetary Astrophysics · Physics 2021-04-02 Marija R. Jankovic , James E. Owen , Subhanjoy Mohanty , Jonathan C. Tan

We use time-dependent, one-dimensional disc models to investigate the evolution of protostellar discs that form through the collapse of molecular cloud cores and in which the primary transport mechanism is self-gravity. We assume that these…

Solar and Stellar Astrophysics · Physics 2015-05-14 W. K. M. Rice , J. H. Mayo , P. J. Armitage

The most intriguing question related to the chemical evolution of protoplanetary disks is the genesis of pre-biotic organic molecules in the planet-forming zone. In this contribution we briefly review current observational knowledge of…

Astrophysics · Physics 2009-11-13 Thomas Henning , Dmitry Semenov

The magnetic field of a molecular cloud core may play a role in the formation of circumstellar disks in the core. We present magnetic field morphologies in protostellar cores of 16 targets in the Atacama Large Millimeter/submillimeter Array…

Given the important role turbulence plays in the settling and growth of dust grains in protoplanetary disks, it is crucial that we determine whether these disks are turbulent and to what extent. Protoplanetary disks are weakly ionized near…

Earth and Planetary Astrophysics · Physics 2024-04-12 David G. Rea , Jacob B. Simon , Daniel Carrera , Geoffroy Lesur , Wladimir Lyra , Debanjan Sengupta , Chao-Chin Yang , Andrew N. Youdin

Whether the angular momentum of protoplanetary discs is redistributed by viscosity or extracted by magnetised winds is a long-standing question. Demographic indicators, such as gas disc sizes and stellar accretion rates, have been proposed…

Earth and Planetary Astrophysics · Physics 2025-02-07 Simin Tong , Richard Alexander , Giovanni Rosotti

Recent observations uncover various phenomena around the protostar such as misalignment between the outflow and magnetic field, precession of the jet, and time variability of the ejected clumps, whose origins are under debate. We perform a…

Solar and Stellar Astrophysics · Physics 2019-03-20 Shingo Hirano , Masahiro N. Machida

We use three dimensional magnetohydrodynamic simulations to study the structure of the boundary layer between an accretion disc and a non-rotating, unmagnetized star. Under the assumption that cooling is efficient, we obtain a narrow but…

Astrophysics · Physics 2009-11-07 Philip J. Armitage

We study the protoplanetary disk lifetimes using a large sample of young stellar objects in nearby clusters. To investigate the final phase of disk dissipation, we selected 32 clusters, located within 500 pc and aged between 1 and 100 Myr,…

Solar and Stellar Astrophysics · Physics 2025-07-03 Gregory Mathews Ben , Jessy Jose , Jesús Hernández

The collapse of the magnetic rotating protostellar cloud with mass of $10\,M_{\odot}$ is numerically studied. The initial ratios of the thermal, magnetic, and rotational energies of the cloud to the modulus of its gravitational energy are…

Solar and Stellar Astrophysics · Physics 2022-10-25 Natalya S. Kargaltseva , Sergey A. Khaibrakhmanov , Alexander E. Dudorov , Andrey G. Zhilkin

In this work we use the radiation hydrodynamic code TRAMP to perform a two-dimensional axially symmetric model of the layered disc. Using this model we follow the accumulation of mass in the dead zone due to the radially varying accretion…

Astrophysics · Physics 2009-11-13 R. Wunsch , H. Klahr , M. Rozyczka

The relaxed motion of stars and gas in galactic discs is well approximated by a rotational velocity that is a function of radial position only, implying that individual components have lost any information about their prior states.…

Astrophysics of Galaxies · Physics 2020-02-11 John Herbert Marr
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