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Related papers: Advective and diffusive cosmic ray transport in ga…

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The diffusive and convective CR transport in NGC 253 from the disk into the halo is investigated using the local CR bulk speed. The connection between the CR transport and the galactic wind is outlined. We observed NGC 253 with the VLA at…

Astrophysics · Physics 2015-05-13 V. Heesen , R. Beck , M. Krause , R. -J. Dettmar

We present low frequency observations at $315$ and $745$ MHz from the upgraded Giant Metrewave Radio Telescope (uGMRT) of the edge-on, nearby galaxy NGC $4631$. We compare the observed surface brightness profiles along the minor axis of the…

Astrophysics of Galaxies · Physics 2022-02-09 Aditi Vijayan , K. S. Dwarakanath , Biman B. Nath , Ruta Kale

We present radio continuum maps of 12 nearby ($D\leq 27~\rm Mpc$), edge-on ($i\geq 76^{\circ}$), late-type spiral galaxies mostly at $1.4$ and 5 GHz, observed with the Australia Telescope Compact Array, Very Large Array, Westerbork…

Low-frequency radio continuum observations of edge-on galaxies are ideal to study cosmic-ray electrons (CREs) in halos via radio synchrotron emission and to measure magnetic field strengths. We obtained new observations of the edge-on…

The diffusive paradigm for the transport of Galactic cosmic rays is central to our understanding of the origin of these high energy particles. However, it is worth recalling that the normalization, energy dependence, and spatial extent of…

High Energy Astrophysical Phenomena · Physics 2018-07-11 Carmelo Evoli , Pasquale Blasi , Giovanni Morlino , Roberto Aloisio

Cosmic rays play a pivotal role in launching galactic winds, particularly in quiescently star-forming galaxies where the hot gas alone is not sufficient to drive a wind. Except for the Milky Way, not much is known about the transport of…

We present the VLA C-array S-band (2--4 GHz) radio continuum observations of the nearby edge-on spiral galaxy NGC 4565, a target from the Continuum Halos in Nearby Galaxies - an EVLA (CHANG-ES) Survey. We conduct rotation measure synthesis…

Radio halos of edge-on galaxies are crucial for investigating cosmic ray propagation and magnetic field structures in galactic environments. We present VLA C-configuration S-band (2--4 GHz) observations of the spiral galaxy NGC 3556, a…

Radio continuum observations of external galaxies provide us with an excellent outside view on the distribution of cosmic-ray electrons in the disc and halo. In this review, we summarise the current state of what we have learned from…

Astrophysics of Galaxies · Physics 2021-12-16 Volker Heesen

We present high-sensitivity radio continuum observations with the VLA and Ryle Telescope at 1.5, 4.9, 8.4 and 15.4 GHz of the dwarf irregular galaxy NGC 1569. The radio data show an extended, irregularly-shaped halo with filamentary…

Astrophysics · Physics 2009-11-10 U. Lisenfeld , T. Wilding , G. G. Pooley , P. Alexander

Isotropic diffusion models for Galactic cosmic ray transport put tight constraints on the maximum convection velocity in the halo. For a half halo height of 4 kpc the maximum convection speed is limited to 40 km/s in the halo, since…

Astrophysics of Galaxies · Physics 2009-10-13 Iris Gebauer , Wim de Boer

Star-forming edge-on galaxies often exhibit extended halo radiation in multiple bands, providing ideal laboratories for studying the transfer of matter from the disk to the halo. We investigate the transport of cosmic-ray electrons (CREs)…

Astrophysics of Galaxies · Physics 2026-03-17 Shengtao Wang , Xiaohui Sun , George Heald , Jiang-Tao Li , Chao-Wei Tsai , Judith Irwin , Theresa Wiegert , Jun Xu

Cosmic-ray electrons (CREs) originating from the star-forming discs of spiral galaxies frequently form extended radio haloes that are best observable in edge-on galaxies. For the present study we selected two nearby edge-on galaxies from…

On-going measurements of the cosmic radiation (nuclear, electronic, and gamma-ray) are shedding new light on cosmic-ray physics. A comprehensive picture of these data relies on an accurate determination of the transport and source…

High Energy Astrophysical Phenomena · Physics 2010-07-08 A. Putze , L. Derome , D. Maurin

Low-frequency radio continuum studies of star-forming edge-on galaxies can help to further understand how cosmic-ray electrons (CRe) propagate through the interstellar medium into the halo and how this is affected by energy losses and…

We present high-sensitivity multi-frequency radio continuum observations of the starburst galaxy NGC~2146. We have fitted these data with a three-dimensional diffusion model. The model can describe the radio emission from the inner disk of…

Astrophysics · Physics 2015-06-24 U. Lisenfeld , P. Alexander , G. G. Pooley , T. Wilding

Using radio polarimetry we study the connection between the transport of cosmic rays (CR's), the three-dimensional magnetic field structure, and features of other ISM phases in the halo of NGC 253. We present a new sensitive radio continuum…

Astrophysics · Physics 2009-11-13 V. Heesen , R. -J. Dettmar , M. Krause , R. Beck

Low-mass galaxies are subject to strong galactic outflows, in which cosmic rays may play an important role, they can be best traced with low-frequency radio continuum observations, which are less affected by spectral ageing. We present a…

In order to gain a better understanding of the influence of cosmic rays (CRs) and magnetic fields in the disk-halo interface of edge-on spiral galaxies, we investigate the radio continuum halo, the magnetic field, and the transport…

Astrophysics of Galaxies · Physics 2020-07-22 Y. Stein , R. -J. Dettmar , R. Beck , J. Irwin , T. Wiegert , A. Miskolczi , Q. D. Wang , J. English , R. Henriksen , M. Radica , J. -T. Li

Radio halos require the coexistence of extra-planar cosmic rays and magnetic fields. Because cosmic rays are injected and accelerated by processes related to star formation in the disk, they have to be transported from the disk into the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Volker Heesen , Rainer Beck , Marita Krause , Ralf-Jürgen Dettmar
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