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Related papers: Steady Galactic Dynamos and Observational Conseque…

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We have explored the dynamical and mass evolution of halos driven by large-scale filaments using a dark matter-only cosmological simulation with the help of a phase-space analysis. Since a non-negligible number of galaxies is expected to…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-18 Hannah Jhee , Hyunmi Song , Rory Smith , Jihye Shin , Inkyu Park , Clotilde Laigle

Cold ($T\sim 10^{4} \ \mathrm{K}$) gas is very commonly found in both galactic and cluster halos. There is no clear consensus on its origin. Such gas could be uplifted from the central galaxy by galactic or AGN winds. Alternatively, it…

Astrophysics of Galaxies · Physics 2018-07-10 Suoqing Ji , S. Peng Oh , Michael McCourt

Matos, Guzman and Nunez proposed a model for the galactic halo within the framework of scalar field theory. We argue that an analysis involving the full metric can reveal the true physical nature of the halo only when a certain condition is…

General Relativity and Quantum Cosmology · Physics 2011-02-01 Kamal K. Nandi , Ildar Valitov , Nail G. Migranov

Faraday tomography allows astronomers to probe the distribution of magnetic field along the line of sight (LOS), but that can be achieved only after Faraday spectrum is interpreted. However, the interpretation is not straightforward, mainly…

Astrophysics of Galaxies · Physics 2017-08-02 Shinsuke Ideguchi , Yuichi Tashiro , Takuya Akahori , Keitaro Takahashi , Dongsu Ryu

We briefly review the recent developments in magnetohydrodynamics, which in particular deal with the evolution of magnetic fields in turbulent plasmas. We especially emphasize (i) the necessity of renormalizing equations of motion in…

Plasma Physics · Physics 2025-05-01 Amir Jafari

We quantify the effects of magnetic fields, cosmic rays and gas pressure on the rotational velocity of HI gas in the Milky Way, at galactic distances between Rsun and 2Rsun. The magnetic field is modelled by two components; a mainly…

Astrophysics of Galaxies · Physics 2015-06-15 F. J. Sanchez-Salcedo , A. Santillan

A fully three-dimensional computation of induction processes in a disk is performed to investigate the evolution of a large-scale magnetic field in gas-rich barred and spiral galaxies in the presence of field diffusion. As input parameters…

Astrophysics · Physics 2007-05-23 S. von Linden , K. Otmianowska-Mazur , H. Lesch , G. Skupniewicz

We study effects of the cross-helicity in the full-sphere large-scale mean-field dynamo models of the 0.3M star rotating with the period of 10 days. In exploring several dynamo scenarios which are stemming from the cross-helicity generation…

Solar and Stellar Astrophysics · Physics 2018-05-23 V. V. Pipin , N. Yokoi

We made use of the two latest sets of Rotational Measures (RMs) of extra-galactic radio sources, namely the NRAO VLA Sky Survey otation Measures Catalogue, and a compilation by Kronberg&Newton-McGee(2011), to infer the global structure of…

Astrophysics of Galaxies · Physics 2015-05-27 M. S. Pshirkov , P. G. Tinyakov , P. P. Kronberg , K. J. Newton-McGee

The kinematics of satellite galaxies moving in a dark matter halo are a direct probe of the underlying gravitational potential. Thus, the phase-space distributions of satellites represent a powerful tool to determine the galaxy-halo…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-22 Johannes U. Lange , Frank C. van den Bosch , Andrew R. Zentner , Kuan Wang , Antonia S. Villarreal

We have extended our previous mean-field galactic dynamo model which included algebraic and dynamic alpha nonlinearities (Kleeorin et al., A&A, v. 387, 453, 2002), to include also a quenching of turbulent diffusivity. We readily obtain…

Astrophysics · Physics 2014-10-13 N. Kleeorin , D. Moss , I. Rogachevskii , D. Sokoloff

It is shown, that the saturated $\alpha$-effect taken from the nonlinear dynamo equations for the thin disk can still produce exponentially growing magnetic field in the case, when this field does not feed back on the $\alpha$. For negative…

Fluid Dynamics · Physics 2015-05-18 M. Reshetnyak

We construct a magnetic helicity conserving dynamo theory which incorporates a calculated magnetic helicity current. In this model the fluid helicity plays a small role in large scale magnetic field generation. Instead, the dynamo process…

Astrophysics · Physics 2009-10-31 Ethan T. Vishniac , Jungyeon Cho

We present a simplified model in which we suggest that two important galactic problems -the magnetic field configuration at large scales and the flat rotation curve- may be simultaneously explained. A highly convective disc produces a high…

Astrophysics · Physics 2007-05-23 E. Battaner , H. Lesch , E. Florido

Observational study of galactic magnetic fields is hampered by the fact that the observables only probe various projections of the magnetic fields. Comparison with numerical simulations is helpful to understand the real structures, and…

Astrophysics of Galaxies · Physics 2018-11-14 Mami Machida , Takuya Akahori , Kenji Nakamura Hiroyuki Nakanishi , Marijke Haverkorn

We present a suite of models of the coherent magnetic field of the Galaxy (GMF) based on new divergence-free parametric functions describing the global structure of the field. The model parameters are fit to the latest full-sky Faraday…

Astrophysics of Galaxies · Physics 2024-08-14 Michael Unger , Glennys R. Farrar

We study an example of instability in presence of a multiplicative noise, namely the spontaneous generation of a magnetic field in a turbulent medium. This so-called turbulent dynamo problem remains challenging, experimentally and…

Astrophysics · Physics 2016-08-16 Nicolas Leprovost , Bérengère Dubrulle

Young solar-type stars rotate rapidly and are very magnetically active. The magnetic fields at their surfaces likely originate in their convective envelopes where convection and rotation can drive strong dynamo action. Here we explore…

Solar and Stellar Astrophysics · Physics 2011-01-04 Benjamin P Brown , Matthew K Browning , Allan Sacha Brun , Mark S Miesch , Juri Toomre

Astrophysical objects with negligible resistivity are often threaded by large scale magnetic fields. The generation of these fields is somewhat mysterious, since a magnetic field in a perfectly conducting fluid cannot change the flux…

Astrophysics · Physics 2007-05-23 E. T. Vishniac , A. Lazarian , J. Cho

Magnetic fields vary in complexity for different stars. The stability of dipolar magnetic fields is known to depend on different quantities, e.g., the stellar rotation, the stratification, and the intensity of convective motions. Here, we…

Solar and Stellar Astrophysics · Physics 2020-09-30 Bonnie Zaire , Laurene Jouve