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Related papers: The effects of vertical outflows on disk dynamos

200 papers

We present the effects of ordered large scale magnetic field on the structure of supercritical accretion flow in the presence of outflow. In the cylindrical coordinates ($r, \varphi,z$), We write the 1.5 dimensional, the steady state…

High Energy Astrophysical Phenomena · Physics 2017-06-21 Maryam Ghasemnezhad , Shahram Abbassi

We investigate the build-up of the galactic dynamo and subsequently the origin of a magnetic driven outflow. We use a setup of an isolated disc galaxy with a realistic circum-galactic medium (CGM). We find good agreement of the galactic…

Astrophysics of Galaxies · Physics 2020-04-01 Ulrich P. Steinwandel , Klaus Dolag , Harald Lesch , Benjamin P. Moster , Andreas Burkert , Almudena Prieto

This paper presents scale invariant/self-similar galactic magnetic dynamo models based on the classic equations, and compares them qualitatively to recently observed magnetic fields in edge-on spiral galaxies. We classify the axially…

Astrophysics of Galaxies · Physics 2021-11-03 R. H. Henriksen , Judith Irwin

We study line driven winds for models with different radial intensity profiles: standard Shakura-Sunyaev radiating thin discs, uniform intensity discs and truncated discs where driving radiation is cutoff at some radius. We find that global…

High Energy Astrophysical Phenomena · Physics 2018-09-19 Sergei Dyda , Daniel Proga

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 the dynamics of toroidal magnetic flux tubes, symmetric about the rotation axis, inside non-magnetic thick accretion disks around black holes. We present model equations which include effects of gravity, centrifugal force, pressure…

Astrophysics · Physics 2009-10-22 Sandip K. Chakrabarti , Sydney D'Silva

The emergence of large-scale magnetic fields observed in the diffuse interstellar medium is explained by a turbulent dynamo. The underlying transport coefficients have previously been extracted from numerical simulations. So far, this was…

Astrophysics of Galaxies · Physics 2015-06-11 Oliver Gressel , Abhijit Bendre , Detlef Elstner

The formation and evolution of a wide class of astrophysical objects is governed by turbulent, magnetized accretion disks. Understanding their secular dynamics is of primary importance. Apart from enabling mass accretion via the transport…

High Energy Astrophysical Phenomena · Physics 2015-09-16 Oliver Gressel , Martin E. Pessah

We study the effect of an imposed vertical magnetic field on the turbulent mass diffusion properties of magnetorotational turbulence in protoplanetary discs. It is well-known that the effective viscosity generated by the turbulence depends…

Astrophysics · Physics 2009-11-11 Anders Johansen , Hubert Klahr , Antony J. Mee

The effects of outflow on the behavior of a viscous gaseous disc around a compact object in an advection-dominated state are examined in this paper. We suppose that the flow is steady, axisymmetric, and rotating. Also, we focus on the model…

High Energy Astrophysical Phenomena · Physics 2025-05-06 Fahimeh Habibi

We investigate outflows from the disk-magnetosphere boundary of rotating magnetized stars in cases where the magnetic field of a star is bunched into an X-type configuration using axisymmetric and full 3D MHD simulations. Such configuration…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. M. Romanova , G. V. Ustyugova , A. V. Koldoba , R. V. E. Lovelace

We present the results of time-dependent, numerical magnetohydrodynamic simulations of a realistic young stellar object outflow model with the addition of a disk-associated magnetic field. The outflow produced by the magnetic star-disk…

Astrophysics · Physics 2009-11-07 S. Matt , R. M. Winglee , K. -H. Bohm

Astrophysical disks are likely embedded in an ambient vertical magnetic field. This ambient field is known to drive magneto-rotational turbulence in the disk bulk but is also responsible for the launching of magnetized outflows at the…

High Energy Astrophysical Phenomena · Physics 2021-03-31 J. Jacquemin-Ide , G. Lesur , J. Ferreira

High surface density, rapidly star-forming galaxies are observed to have $\approx 50-100\,{\rm km\,s^{-1}}$ line-of-sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale…

Astrophysics of Galaxies · Physics 2016-02-17 Sharanya Sur , Evan Scannapieco , Eve C. Ostriker

The existence of outflow in accretion flows is confirmed by observations and magnetohydrodynamics (MHD) simulations. In this paper, we study outflows of accretion flows in the presence of resistivity and toroidal magnetic field. The…

High Energy Astrophysical Phenomena · Physics 2012-05-11 Kazem Faghei , Azam Mollatayefeh

Nonlinear behaviour of galactic dynamos is studied, allowing for magnetic helicity removal by the galactic fountain flow. A suitable advection speed is estimated, and a one-dimensional mean-field dynamo model with dynamic alpha-effect is…

Astrophysics · Physics 2007-05-23 Anvar Shukurov , Dmitry Sokoloff , Kandaswamy Subramanian , Axel Brandenburg

Accretion disks are likely threaded by external vertical magnetic flux, which enhances the level of turbulence via the magnetorotational instability (MRI). Using shearing-box simulations, we find that such external magnetic flux also…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Xue-Ning Bai , James M. Stone

Outflows driven by large-scale magnetic fields likely play an important role in the evolution and dispersal of protoplanetary disks, and in setting the conditions for planet formation. We extend our 2-D axisymmetric non-ideal MHD model of…

Earth and Planetary Astrophysics · Physics 2020-07-01 Oliver Gressel , Jon P. Ramsey , Christian Brinch , Richard P. Nelson , Neal J. Turner , Simon Bruderer

Observational evidence and theoretical arguments postulate that outflows may play a significant role in the advection-dominated accretion discs (ADAFs). While the azimuthal viscosity is the main focus of most previous studies in this…

High Energy Astrophysical Phenomena · Physics 2020-03-18 S. M. Ghoreyshi , M. Shadmehri

Mean-field dynamo theory has important applications in solar physics and galactic magnetism. We discuss some of the many turbulence effects relevant to the generation of large-scale magnetic fields in the solar convection zone. The…

Solar and Stellar Astrophysics · Physics 2023-11-23 Axel Brandenburg , Detlef Elstner , Youhei Masada , Valery Pipin