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Related papers: Helicity in the Large-Scale Galactic Magnetic Fiel…

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Statistical properties of turbulent magnetic fields in radio-synchrotron sources should imprint on the statistics of polarimetric observables. In search of these imprints, we calculate correlation and cross-correlation functions from a set…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 H. Junklewitz , T. A. Enßlin

Interpretations of synchrotron observations often assume a tight correlation between magnetic and cosmic ray energy densities. We examine this assumption using both test-particle simulations of cosmic rays and MHD simulations which include…

Astrophysics of Galaxies · Physics 2018-10-10 Amit Seta , Anvar Shukurov , Paul J. Bushby , Toby S. Wood

The role of magnetic helicity in astrophysical large-scale dynamos is reviewed and compared with cases where there is no energy supply and an initial magnetic field can only decay. In both cases magnetic energy tends to get redistributed to…

Solar and Stellar Astrophysics · Physics 2009-11-13 Axel Brandenburg

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

We simulate an isolated, magnetised Milky Way-like disc galaxy using a self-consistent model of unresolved star formation and feedback, evolving the system until it reaches statistical steady state. We show that the quasi-steady-state…

Astrophysics of Galaxies · Physics 2022-09-28 Benjamin D. Wibking , Mark R. Krumholz

In order to better determine the large-scale 3D-structure of magnetic fields in spiral galaxies we present a Faraday rotation analysis of the edge-on spiral galaxy NGC 5775. Deep radio-continuum observations in total power and linear…

Astrophysics of Galaxies · Physics 2015-05-28 Marian Soida , Marita Krause , Ralf-Jürgen Dettmar , Marek Urbanik

Observational evidence for dynamo action in spiral galaxies is reviewed, and the capabilities of various theories in explaining the basic features of galactic magnetic fields are discussed. Mean-field dynamo models appear to be unique in…

Astrophysics · Physics 2007-05-23 Anvar Shukurov

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 Galactic magnetic field plays an important role in the evolution of the Galaxy, but its small-scale behaviour is still poorly known. It is also unknown whether it permeates the halo of the Galaxy or not. By using observations of pulsars…

High Energy Astrophysical Phenomena · Physics 2020-03-09 Federico Abbate , Andrea Possenti , Caterina Tiburzi , Ewan Barr , Willem van Straten , Alessandro Ridolfi , Paulo Freire

Magnetic fields in the Milky Way are present on a wide variety of sizes and strengths, influencing many processes in the Galactic ecosystem such as star formation, gas dynamics, jets, and evolution of supernova remnants or pulsar wind…

Magnetic fields are of critical importance for our understanding of the origin and long-term evolution of the Milky Way. This is due to their decisive role in the dynamical evolution of the interstellar medium (ISM) and their influence on…

Even though magnetic fields play an important role in galaxy evolution, the redshift evolution of galactic-scale magnetic fields is not well constrained observationally. In this paper we aim to provide an observational constraint on the…

Astrophysics of Galaxies · Physics 2025-07-18 Timea Orsolya Kovacs , Sui Ann Mao , Aritra Basu , Yik Ki Ma , B. M. Gaensler

We report the detection of polarized emission in the vicinity of the Galactic center for 158 positions within eight different pointings of the Hertz polarimeter operating on the Caltech Submillimeter Observatory. These pointings include…

The large-scale magnetic field of our Galaxy can be probed in three dimensions using Faraday rotation of pulsar signals. We report on the determination of 223 rotation measures from polarization observations of relatively distant southern…

Astrophysics · Physics 2011-05-05 J. L. Han , R. N. Manchester , A. G. Lyne , G. J. Qiao , W. van Straten

The magnetic fields observed in the Milky~Way and nearby galaxies appear to be in equipartition with the turbulent, thermal, and cosmic ray energy densities, and hence are expected to be dynamically important. However, the origin of these…

The origin and evolution of cosmic magnetic fields as well as the influence of the magnetic fields on the evolution of galaxies are unknown. Though not without challenges, the dynamo theory can explain the large-scale coherent magnetic…

Astrophysics of Galaxies · Physics 2016-02-17 F. S. Tabatabaei , T. P. K. Martinsson , J. H. Knapen , J. E. Beckman , B. Koribalski , B. G. Elmegreen

The all-sky survey of Faraday rotation, a Key Science Project of the planned Square Kilometre Array, will accumulate tens of millions of rotation measure measurements toward background radio sources and will provide a unique database for…

Astrophysics · Physics 2009-11-11 Rainer Beck

In helical hydromagnetic turbulence with an imposed magnetic field (which is constant in space and time) the magnetic helicity of the field within a periodic domain is no longer an invariant of the ideal equations. Alternatively, there is a…

Astrophysics · Physics 2009-11-07 Axel Brandenburg , William H. Matthaeus

We investigate analytically the amplification of a weak magnetic field in a homogeneous and isotropic turbulent flow lacking reflectional symmetry (helical turbulence). We propose that the spectral distributions of magnetic energy and…

Astrophysics · Physics 2007-05-23 Stanislav Boldyrev , Fausto Cattaneo , Robert Rosner

Cosmological magnetic fields induce temperature and polarization fluctuations in the cosmic microwave background (CMB) radiation. A cosmological magnetic field with current amplitude of order $10^{-9}$ G is detectable via observations of…

Astrophysics · Physics 2009-11-10 Tina Kahniashvili , Bharat Ratra , ;