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We argue that any violent galactic winds following early epoch of star bursts would significantly weaken the potentials of galaxies, and leave lasting signatures such as a lowered dark halo density and preferentially radial/escaping orbits…

Astrophysics · Physics 2009-11-07 HongSheng Zhao

The turbulent dynamo may explain the origin of cosmic magnetism. While the exponential amplification of magnetic fields has been studied for incompressible gases, little is known about dynamo action in highly-compressible, supersonic…

Astrophysics of Galaxies · Physics 2014-12-05 Christoph Federrath , Jennifer Schober , Stefano Bovino , Dominik R. G. Schleicher

Little is known about the origin and basic properties of magnetic fields in clusters of galaxies. High conductivity in magnetized interstellar plasma suggests that galactic magnetic fields are (at least partly) ejected into intracluster…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Yinon Arieli , Yoel Rephaeli , Michael L. Norman

The origin of large magnetic fields ($\gtrsim 10^6~\mathrm{G}$) in isolated white dwarfs is not clear. One possible explanation is that crystallization of the star's core drives compositional convection, which when combined with the star's…

Solar and Stellar Astrophysics · Physics 2024-03-20 J. R. Fuentes , Matias Castro-Tapia , Andrew Cumming

For understanding the nature of gaseous flows in star-forming regions of nearby galaxies it is usually utilized the relation between surface brightness in H$\alpha$ line and velocity dispersion of ionized gas known as ''surface brightness…

Astrophysics of Galaxies · Physics 2024-04-02 Evgemii O. Vasiliev , Yuri A. Shchekinov

Observations of magnetism in very low mass stars recently made important progress, revealing characteristics that are now to be understood in the framework of dynamo theory. In parallel, there is growing evidence that dynamo processes in…

Solar and Stellar Astrophysics · Physics 2015-05-28 J. Morin , E. Dormy , M. Schrinner , J. -F. Donati

Many spiral galaxies host magnetic fields with energy densities comparable to those of the turbulent and thermal motions of their interstellar gas. However, quantitative comparison between magnetic field properties inferred from observation…

Astrophysics of Galaxies · Physics 2025-08-05 Rion Glenn Nazareth , Gayathri Santhosh , Luke Chamandy

We seek to obtain a picture of the interstellar magnetic field in the Galactic center region that is as clear and complete as possible. To that end, we review the observational knowledge that has built up over the past 25 years on…

Astrophysics of Galaxies · Physics 2015-05-13 Katia Ferriere

Advances in instrumentation have recently extended detailed measurements of gas kinematics to large samples of high-redshift galaxies. Relative to most nearby, thin disk galaxies, in which gas rotation accurately traces the gravitational…

We characterize stellar, gas, and dark matter mass distributions for 17 nearby massive disk galaxies from the PHANGS sample. This allows us to compute the gravitational potential that vertically confines the interstellar gas and determines…

Glorified dimensional analysis is used to derive scaling rules for internal and external magnetic field strengths and various time scales. Naive dimensional analysis is inconclusive because of multiple time scales, but physical arguments…

Solar and Stellar Astrophysics · Physics 2016-03-31 Bertrand Barrois

Some common properties of helical magnetic fields in decaying and driven turbulence are discussed. These include mainly the inverse cascade that produces fields on progressively larger scales. Magnetic helicity also restricts the evolution…

Astrophysics · Physics 2007-05-23 Axel Brandenburg

We seek the conditions for a {\it steady} mean field galactic dynamo. The parameter set is reduced to those appearing in the $\alpha^2$ and $\alpha/\omega$ dynamo, namely velocity amplitudes, and the ratio of sub-scale helicity to…

Astrophysics of Galaxies · Physics 2017-06-28 R. N. Henriksen

We investigate the kinematics of the molecular gas in a sample of seven edge-on (i>60{\deg}) galaxies identified as hosting large-scale outflows of ionised gas, using ALMA CO(1-0) observations at ~ 1kpc resolution. We build on Hogarth et…

Astrophysics of Galaxies · Physics 2022-11-09 Lucy M. Hogarth , Amelie Saintonge , Tim A. Davis

Possibilities and difficulties of applying the theory of magnetic field generation by convection flows in rotating spherical fluid shells to the Giant Planets are outlined. Recent progress in the understanding of the distribution of…

Earth and Planetary Astrophysics · Physics 2009-06-02 F. H. Busse , R. D. Simitev

We present a simple semi-analytical model of nonlinear, mean-field galactic dynamos and use it to study the effects of various magnetic helicity fluxes. The dynamo equations are reduced using the `no-$z$' approximation to a nonlinear system…

Astrophysics · Physics 2008-11-26 Sharanya Sur , Anvar Shukurov , Kandaswamy Subramanian

We consider the diffusive shock acceleration in interstellar bubbles created by powerful stellar winds of supernova progenitors. Under the moderate stellar wind magnetization the bubbles are filled by the strongly magnetized low density…

High Energy Astrophysical Phenomena · Physics 2018-02-14 V. N. Zirakashvili , V. S. Ptuskin

We examine the effect of weak, small scale magnetic field structure on the rate of reconnection in a strongly magnetized plasma. This affects the rate of reconnection by reducing the transverse scale for reconnection flows, and by allowing…

Astrophysics · Physics 2016-08-30 A. Lazarian , E. T. Vishniac

We wish to clarify whether strong magnetic fields can be effectively generated in typically low-mass dwarf galaxies and to assess the role of dwarf galaxies in the magnetization of the Universe. We performed a search for radio emission and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Krzysztof T. Chyzy , Marek Wezgowiec , Rainer Beck , Dominik J. Bomans

Magnetic fields play such roles in star formation as the angular momentum transport in star-forming clouds, thereby controlling circumstellar disc formation and even binary star formation efficiency. The coupling between the magnetic field…

Astrophysics of Galaxies · Physics 2019-07-17 Daisuke Nakauchi , Kazuyuki Omukai , Hajime Susa
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