English
Related papers

Related papers: New Insights on Galactic Dynamos

200 papers

Large-scale magnetic fields in galaxies are thought to be generated by a turbulent dynamo. However the same turbulence also leads to a small-scale dynamo which generates magnetic noise at a more rapid rate. The efficiency of the large-scale…

Astrophysics · Physics 2020-11-25 K. Subramanian

Cosmology, high-energy physics and astrophysics are converging on the study of large-scale magnetic fields. While the experimental evidence for the existence of large-scale magnetization in galaxies, clusters and superclusters is rather…

Astrophysics · Physics 2009-11-10 Massimo Giovannini

Magnetic fields have been included in cosmological simulations of galaxy formation only recently, due to advances in numerical techniques and a better understanding of the galaxy formation physics. In this paper, we develop a new subgrid…

Astrophysics of Galaxies · Physics 2022-05-13 Yuankang Liu , Michael Kretschmer , Romain Teyssier

Total magnetic fields in spiral galaxies, as observed through their total synchrotron emission, are strongest (up to \simeq 30\mu G) in the spiral arms. The degree of radio polarization is low; the field in the arms must be mostly turbulent…

Astrophysics · Physics 2009-11-11 Rainer Beck

We discuss the amplification of magnetic fields by the small-scale dynamo, a process that could efficiently produce strong magnetic fields in the first galaxies. In addition, we derive constraints on the primordial field strength from the…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-14 Dominik R. G. Schleicher , Jennifer Schober , Christoph Federrath , Francesco Miniati , Robi Banerjee , Ralf S. Klessen

Magnetic fields constitute an energetic component of the interstellar medium in galaxies and hence can affect the formation of galactic structures. Sensitive resolved radio continuum observations together with statistical studies in galaxy…

Astrophysics of Galaxies · Physics 2018-11-20 Fatemeh S. Tabatabaei

Galactic winds from star-forming galaxies are crucial to the process of galaxy formation and evolution, regulating star formation, shaping the stellar mass function and the mass-metallicity relation, and enriching the intergalactic medium…

Astrophysics of Galaxies · Physics 2018-11-05 Dong Zhang

Multi-frequency radio polarimetry of the diffuse Galactic synchrotron background gives new viewpoints on the Galactic magnetic field. Rotation measure maps reveal magnetic structures on arcminute to degree scales, such as a ring in…

Astrophysics · Physics 2015-06-24 M. Haverkorn , P. Katgert , A. G. de Bruyn , F. Heitsch

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

Fluctuation dynamos are thought to play an essential role in magnetized galaxy evolution, saturating within $\sim0.01~$Gyr and thus potentially acting as seeds for large-scale dynamos. However, unambiguous observational confirmation of the…

Astrophysics of Galaxies · Physics 2021-01-20 Amit Seta , Luiz Felippe S. Rodrigues , Christoph Federrath , Christopher A. Hales

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

The geo and solar magnetic fields have long been thought to be very different objects both in terms of spatial structure and temporal behavior. The recently discovered field structure of a fully convective star is more reminiscent of…

Earth and Planetary Astrophysics · Physics 2009-07-30 Laure Goudard , Emmanuel Dormy

Galaxies are observed to obey a strict set of dynamical scaling relations. We review these relations for rotationally supported disk galaxies spanning many decades in mass, surface brightness, and gas content. The behavior of these widely…

Astrophysics of Galaxies · Physics 2020-05-20 Stacy McGaugh , Federico Lelli , Pengfei Li , Jim Schombert

Galactic disks lie at the heart of many of the most pressing astrophysical puzzles. There are sophisticated kinetic theories that describe some aspects of galaxy disk dynamics, but extracting quantitative predictions from those theories has…

Astrophysics of Galaxies · Physics 2025-12-09 Chris Hamilton , Shaunak Modak , Scott Tremaine

The exteriors of stellar and galactic dynamos are usually modeled as current-free potential fields. A more realistic description might instead be that of a force-free magnetic field. Here, we suggest that, in the absence of outflows,…

High Energy Astrophysical Phenomena · Physics 2026-05-06 Axel Brandenburg , Oindrila Ghosh , Franco Vazza , Andrii Neronov

Astrophysical processes can contribute to magnetic fields within cosmic voids either through magnetized outflows from the astrophysical large-scale structure or through superposition of dipolar contributions from individual galaxies. Such…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-06 Károly Seller , Günter Sigl

This is a review of the status of efforts to model the large-scale Galactic magnetic field (GMF). Though important for a variety of astrophysical processes, the GMF remains poorly understood despite some interesting new tracers being used…

Astrophysics of Galaxies · Physics 2019-05-14 Tess R. Jaffe

We review the literature concerning how the cosmic magnetic fields pervading nearly all galaxies actually got started. some observational evidence involves the chemical abundance of the light elements Be and B, while another one is based on…

Astrophysics · Physics 2009-11-13 Russell M. Kulsrud , Ellen G. Zweibel

Spin patterns of spiral galaxies can be broadly separated into galaxies with clockwise (Z-wise) patterns and galaxies with counterclockwise (S-wise) spin patterns. While the differences between these patterns are visually noticeable, they…

Astrophysics of Galaxies · Physics 2017-09-01 Lior Shamir

Interstellar magnetic fields are strong: up to 25 muG in spiral arms and 40 muG in nuclear regions. In the spiral galaxy NGC 6946 the average magnetic energy density exceeds that of the thermal gas. Magnetic fields control the evolution of…

Astrophysics · Physics 2017-01-25 Rainer Beck