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Related papers: Strong magnetic fields and cosmic rays in very you…

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We study the global evolution of the magnetic field and interstellar medium (ISM) of the barred and ringed galaxies in the presence of non-axisymmetric components of the potential, i.e. the bar and/or the oval perturbations. The…

Astrophysics of Galaxies · Physics 2015-05-20 K. Kulpa-Dybeł , K. Otmianowska-Mazur , B. Kulesza-Żydzik , G. Kowal , D. Wóltański , M. Hanasz , K. Kowalik

Magnetic fields play a vital role in numerous astrophysical processes such as star formation and the interstellar medium. In particular, their role in the formation and evolution of galaxies is not well understood. This paper presents…

Astrophysics of Galaxies · Physics 2021-12-10 Huai-Hsuan Chiu , Ke-Jung Chen

The origin and growth of magnetic fields in galaxies is still something of an enigma. It is generally assumed that seed fields are amplified over time through the dynamo effect, but there are few constraints on the timescale. It has…

The origin and evolution of magnetic fields in the Universe is still an open question. Their observations in galaxies suggest strong magnetic fields already at high redshift as well as at present time. However, neither primordial magnetic…

Astrophysics of Galaxies · Physics 2017-04-21 Michael Rieder , Romain Teyssier

Magnetic fields are considered as a vital ingredient of contemporary star formation, and may have been important during the formation of the first stars in the presence of an efficient amplification mechanism. Initial seed fields are…

Astrophysics of Galaxies · Physics 2016-01-20 Muhammad A. Latif , Dominik R. G. Schleicher

We present new developments on the Cosmic--Ray driven, galactic dynamo, modeled by means of direct, resistive CR--MHD simulations, performed with ZEUS and PIERNIK codes. The dynamo action, leading to the amplification of large--scale…

Although Galactic cosmic rays (protons and nuclei) are widely believed to be dominantly accelerated by the winds and supernovae of massive stars, definitive evidence of this origin remains elusive nearly a century after their discovery [1].…

We show that strong magnetic fields can be generated at shock waves associated with formation of galaxies or clusters of galaxies by the Weibel instability, an instability in collisionless plasmas. The estimated strength of the magnetic…

Astrophysics · Physics 2015-06-24 Yutaka Fujita , Tsunehiko N. Kato

Spiral galaxies, including the Milky Way, have large-scale magnetic fields with significant energy densities. The dominant theory attributes these magnetic fields to a large-scale dynamo. We review the current status of dynamo theory and…

Astrophysics of Galaxies · Physics 2023-08-31 Axel Brandenburg , Evangelia Ntormousi

We investigate the appearance of magnetic field amplification resulting from a cosmic ray escape current in the context of supernova remnant shock waves. The current is inversely proportional to the maximum energy of cosmic rays, and is a…

High Energy Astrophysical Phenomena · Physics 2015-06-16 K. M. Schure , A. R. Bell

There is evidence that cosmic rays were present in galaxies at moderately high redshift. This suggests that magnetic fields were also present. If cosmic rays and magnetic fields must always be close to equipartition, as they are to an order…

Astrophysics · Physics 2009-11-07 Ellen G. Zweibel

The evolution of magnetic fields in galaxies is still an open problem in astrophysics. In nearby galaxies the far-infrared-radio correlation indicates the coupling between magnetic fields and star formation. The correlation arises from the…

Astrophysics of Galaxies · Physics 2015-06-19 Jennifer Schober , Dominik R. G. Schleicher , Ralf S. Klessen

Galaxies at high redshifts with strong star formation are sources of high-energy cosmic rays. These cosmic rays interact with the baryon and radiation fields of the galactic environment via photo-pair, photo-pion and proton-proton processes…

High Energy Astrophysical Phenomena · Physics 2017-08-24 Ellis R. Owen , Kinwah Wu , Pooja Surajbali , Idunn B. Jacobsen

Stellar dynamos are driven by complex couplings between rotation and turbulent convection, which drive global-scale flows and build and rebuild stellar magnetic fields. When stars like our sun are young, they rotate much more rapidly than…

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 are an important ingredient of the interstellar medium (ISM). Besides their importance for star formation, they govern the transport of cosmic rays, relevant to the launch and regulation of galactic outflows and winds, which…

Radio continuum observations allow to reveal the magnetic field structure in the disk and halo of nearby spiral galaxies, their magnetic field strength and vertical scale heights. The spiral galaxies studied so far show a similar magnetic…

Astrophysics of Galaxies · Physics 2014-01-08 Marita Krause

It is shown that the standard cosmological model predicts {\it ab initio} generation of large-scale but very small-amplitude cosmic magnetic fields at the epoch of recombination of the primeval plasma. Matter velocities dominated by…

Astrophysics · Physics 2007-05-23 Craig J. Hogan

An overview is given of multiwavelength observations of young supernova remnants, with a focus on the observational signatures of efficient cosmic ray acceleration. Some of the effects that may be attributed to efficient cosmic ray…

Astrophysics · Physics 2009-11-13 Jacco Vink

We study the generation and maintenance of large-scale magnetic fields in barred galaxies. We take a velocity field (with strong noncircular components) from a published gas dynamical simulation of Athanassoula (1992), and use this as input…

Astrophysics · Physics 2009-11-06 D. Moss , A. Shukurov , D. Sokoloff , R. Beck , A. Fletcher