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Related papers: Cosmic ray driven dynamo in barred and ringed gala…

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Star-forming dwarf galaxies can be seen as the local proxies of the high-redshift building blocks of more massive galaxies according to the current paradigm of the hierarchical galaxy formation. They are low-mass objects, and therefore…

Astrophysics of Galaxies · Physics 2015-06-18 H. Siejkowski , K. Otmianowska-Mazur , M. Soida , D. J. Bomans , M. Hanasz

Cosmic rays (CRs) are transported out of the galaxy by diffusion and advection due to streaming along magnetic field lines and resonant scattering off self-excited Magneto-Hydro-Dynamic (MHD) waves. Thus momentum is transferred to the…

Astrophysics of Galaxies · Physics 2019-10-02 E. A. Dorfi , D. Steiner , F. Ragossnig , D. Breitschwerdt

Galactic-scale winds are a generic feature of massive galaxies with high star formation rates across a broad range of redshifts. Despite their importance, a detailed physical understanding of what drives these mass-loaded global flows has…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Munier Salem , Greg L. Bryan

Cosmic rays (CRs) are a plausible mechanism for launching winds of cool material from the discs of star-forming galaxies. However, there is no consensus on what types of galaxies likely host CR-driven winds, or what role these winds might…

Astrophysics of Galaxies · Physics 2021-03-03 Roland M. Crocker , Mark R. Krumholz , Todd A. Thompson

Radio observations show that magnetic fields are present in dwarf irregular galaxies (dIrr) and its strength is comparable to that found in spiral galaxies. Slow rotation, weak shear and shallow gravitational potential are the main features…

Astrophysics of Galaxies · Physics 2015-05-27 H. Siejkowski , M. Soida , K. Otmianowska-Mazur , M. Hanasz , D. J. Bomans

Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 \muG) in the spiral arms where they are mostly turbulent or…

Astrophysics · Physics 2009-06-23 Rainer Beck

The interaction of cosmic rays (CRs) with magnetic fields and the interstelar medium (ISM) leads to the production of nonthermal radiation. Although this has been a topic of study for many years, it still poses many challenges to the…

Low-mass galaxies radio observations show in many cases surprisingly high levels of magnetic field. The mass and kinematics of such objects do not favour the development of effective large-scale dynamo action. We attempted to check if the…

Astrophysics of Galaxies · Physics 2018-03-14 Hubert Siejkowski , Marian Soida , Krzysztof T. Chyzy

In star-forming galaxies, the far-infrared (FIR) and radio-continuum luminosities obey a tight empirical relation over a large range of star-formation rates (SFR). We examine magneto-hydrodynamic galaxy simulations with cosmic rays (CRs),…

Astrophysics of Galaxies · Physics 2022-07-20 Christoph Pfrommer , Maria Werhahn , Rüdiger Pakmor , Philipp Girichidis , Christine M. Simpson

We study the properties of cosmic-ray (CR) driven galactic winds from the warm interstellar medium using idealized spherically symmetric time-dependent simulations. The key ingredients in the model are radiative cooling and…

Astrophysics of Galaxies · Physics 2023-08-11 Shaunak Modak , Eliot Quataert , Yan-Fei Jiang , Todd A. Thompson

From our radio observations of the magnetic field strength and large-scale pattern of spiral galaxies of different Hubble types and star formation rates (SFR) we conclude that - though a high SFR in the disk increases the total magnetic…

Astrophysics of Galaxies · Physics 2009-11-13 Marita Krause

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

Cosmic rays (CRs) and magnetic fields may be dynamically important in driving large-scale galactic outflows from rapidly star-forming galaxies. We construct two-dimensional axisymmetric models of the local starburst and super-wind galaxy…

Astrophysics of Galaxies · Physics 2020-04-29 Benjamin J. Buckman , Tim Linden , Todd A. Thompson

The diffusion of cosmic rays (CRs) in turbulent magnetic fields is fundamental to understand various astrophysical processes. We explore the CR diffusion in the magnetic fluctuations amplified by the nonlinear turbulent dynamo, in the…

High Energy Astrophysical Phenomena · Physics 2024-12-03 Chao Zhang , Siyao Xu

Cosmic rays (CRs) leave their sources mainly along the local magnetic field; in doing so they excite both resonant and nonresonant modes through streaming instabilities. The excitation of these modes leads to enhanced scattering and in turn…

High Energy Astrophysical Phenomena · Physics 2021-06-10 Benedikt Schroer , Oreste Pezzi , Damiano Caprioli , Colby Haggerty , Pasquale Blasi

The theory of Galactic Winds, driven by the cosmic-ray pressure gradient, is reviewed both on the magnetohydrodynamic and on the kinetic level. In this picture the magnetic field of the Galaxy above the dense gas disk is assumed to have a…

High Energy Astrophysical Phenomena · Physics 2014-11-06 Heinrich J. Völk

The physics of cosmic rays (CR) is a promising candidate for explaining the driving of galactic winds and outflows. Recent galaxy formation simulations have demonstrated the need for active CR transport either in the form of diffusion or…

Astrophysics of Galaxies · Physics 2016-07-19 Ruediger Pakmor , Christoph Pfrommer , Christine M. Simpson , Volker Springel

We present a scenario for efficient magnetization of very young galaxies about 0.5 Gigayears after the Big-Bang by a cosmic ray-driven dynamo. These objects experience a phase of strong star formation during this first $10^9$ years. We…

Astrophysics · Physics 2009-11-07 H. Lesch , M. Hanasz

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

Observations show that the magnetic field in young supernova remnants (SNRs) is significantly stronger than can be expected from the compression of the circumstellar medium (CSM) by a factor of four expected for strong blast waves.…

Astrophysics of Galaxies · Physics 2009-08-05 K. M. Schure , J. Vink , A. Achterberg , R. Keppens