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相关论文: Dust-driven Dynamos in Accretion Disks

200 篇论文

The origin of cosmic magnetic (B) fields remains an open question. It is generally believed that very weak primordial B fields are amplified by dynamo processes, but it appears unlikely that the amplification proceeds fast enough to account…

宇宙学与河外天体物理 · 物理学 2015-05-13 Ioannis Contopoulos , Dimitris M. Christodoulou , Demosthenes Kazanas , Denise C. Gabuzda

Mass ejection in the form of winds or jets appears to be as fundamental to quasar activity as accretion, and can be directly observed in many objects with broadened and blue-shifted UV absorption features. A convincing argument for…

宇宙学与河外天体物理 · 物理学 2013-03-29 S. C. Gallagher , M. M. Abado , J. E. Everett , S. Keating , R. P. Deo

Magnetic fields play an important role in astrophysical accretion discs, and in the interstellar and intergalactic medium. They drive jets, suppress fragmentation in star-forming clouds and can have a significant impact on the accretion…

等离子体物理 · 物理学 2016-12-30 Christoph Federrath

We report the strength of seed magnetic flux of accretion disk surrounding the PopIII stars. The magnetic field in accretion disk might play an important role in the transport of angular momentum because of the turbulence induced by…

天体物理学 · 物理学 2009-11-10 Hideki Maki , Hajime Susa

We investigate the linear growth and vertical structure of the MRI in protoplanetary discs when dust grains are well mixed with the gas over the entire disc thickness. All the grains have the same radius (a = 0.1, 1 or 3 micron) and…

天体物理学 · 物理学 2009-11-13 Raquel Salmeron , Mark Wardle

[Abridged] Aims. We provide an important step toward a better understanding of the magnetorotational instability (MRI)-dust coevolution in protoplanetary disks by presenting a proof of concept that dust evolution ultimately plays a crucial…

Accretion discs are composed of ionized gas in motion around a central object. Sometimes, the disc is the source of powerful bipolar jets along its rotation axis. Theoretical models invoke the existence of a bipolar magnetic field crossing…

高能天体物理现象 · 物理学 2011-12-23 Remi de Guiran , Jonathan Ferreira

We argue that charged dust grains could significantly impact the confinement and transport of galactic cosmic rays. For sub-GeV to ~1000GeV cosmic rays, small-scale parallel Alfv\'en waves, which isotropize cosmic rays through gyro-resonant…

高能天体物理现象 · 物理学 2021-02-03 Jonathan Squire , Philip F Hopkins , Eliot Quataert , Philipp Kempski

During the evolution of protoplanetary disks, dust grains start to grow, form larger particles, settle to the midplane, and rearrange the disk, mainly by the inward radial drift. Because of this, dust pebbles with an irregular shape usually…

地球与行星天体物理 · 物理学 2025-11-05 Moritz Lietzow-Sinjen , Stefan Reissl , Mario Flock , Sebastian Wolf

The formation of astrophysical objects of different nature and size, from black holes to gaseous giant planets, involves a disk-jet system, where the disk drives the mass accretion onto a central compact object and the jet is a fast…

太阳与恒星天体物理 · 物理学 2022-09-02 Luca Moscadelli , Alberto Sanna , Henrik Beuther , André Oliva , Rolf Kuiper

The paper reports on the dynamics of a 3-dimensional dusty plasma in a strong magnetic field. An electrostatic potential well created by a conducting or non-conducting ring in the rf discharge confines the charged dust particles. In the…

等离子体物理 · 物理学 2020-06-24 Mangilal Choudhary , Roman Bergert , Slobodan Mitic , Markus H. Thoma

We review advances in the theoretical and computational studies of disk winds, jets and outflows including: the connection between accretion and jets, the launch of jets from magnetized disks, the coupled evolution of jets and disks, the…

天体物理学 · 物理学 2007-05-23 Ralph E. Pudritz , Rachid Ouyed , Christian Fendt , Axel Brandenburg

We study stability of a dust layer in a gaseous disc subject to the linear axisymmetric perturbations. Instead of considering single-size particles, however, the population of dust particles is assumed to consist of two grain species. Dust…

星系天体物理 · 物理学 2015-12-15 Mohsen Shadmehri

Magnetic fields are considered as a vital ingredient of contemporary star formation, and may have been important during the formation of the first stars in the presence of an efficient amplification mechanism. Initial seed fields are…

星系天体物理 · 物理学 2016-01-20 Muhammad A. Latif , Dominik R. G. Schleicher

Dust coagulation in protoplanetary disks is not straightforward and is subject to several slow-down mechanisms, such as bouncing, fragmentation and radial drift to the star. Furthermore, dust grains in UV-shielded disk regions are…

太阳与恒星天体物理 · 物理学 2023-08-09 Vitaly Akimkin , Alexei V. Ivlev , Paola Caselli , Munan Gong , Kedron Silsbee

Astrophysical accretion flows are associated with energetic emission of radiation and outflows (winds and jets). Extensive observations of these two processes in X-ray binary outbursts are available. A convincing understanding of their…

高能天体物理现象 · 物理学 2019-01-11 Ioannis Contopoulos

We briefly review recent developments in black hole accretion disk theory, placing new emphasis on the vital role played by magnetohydrodynamic (MHD) stresses in transporting angular momentum. The apparent universality of accretion-related…

天体物理学 · 物理学 2009-06-23 Zdenka Kuncic , Geoffrey V. Bicknell

There is a long-standing discussion in the astrophysical/astrochemical community as to the structure and morphology of dust grains in various astrophysical environments (e.g., interstellar clouds, protostellar envelopes, protoplanetary and…

Pre-main-sequence stars are observed to be surrounded by both accretion flows and some kind of wind or jet-like outflow. Recent work by Matt and Pudritz has suggested that if classical T Tauri stars exhibit stellar winds with mass loss…

天体物理学 · 物理学 2009-11-13 Steven R. Cranmer

Supernova ejecta and stellar winds are believed to produce interstellar dust grains with relatively large sizes. Smaller grains can be produced via the shattering of large grains that have been stochastically accelerated. To understand this…

星系天体物理 · 物理学 2022-12-07 Eric R. Moseley , Romain Teyssier , B. T. Draine