Cosmic-ray electron transport in the galaxy M 51. (arXiv:2206.11670v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Dorner_J/0/1/0/all/0/1">Julien Dörner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reichherzer_P/0/1/0/all/0/1">Patick Reichherzer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tjus_J/0/1/0/all/0/1">Julia Becker Tjus</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Heesen_V/0/1/0/all/0/1">Volker Heesen</a>
Indirect observations of the cosmic-ray electron (CRE) distribution via
synchrotron emission is crucial for deepening the understanding of the CRE
transport in the interstellar medium, and in investigating the role of galactic
outflows. In this paper, we quantify the contribution of diffusion and
advection dominated transport of cosmic-ray electrons in the galaxy M51
considering relevant energy loss processes. We use recent measurement from M51
that allow for the derivation of the diffusion coefficient, the star formation
rate, and the magnetic field strength. With this input, we solve the 3D
transport equation numerically including the spatial dependence as provided by
the measurements, using the open-source transport framework CRPropa (v3.1). We
include three-dimensional transport (diffusion and advection), and the relevant
loss processes. We find that the data can be described well with the parameters
from recent measurements. For the best fit, it is required that the wind
velocity, following from the observed star formation rate, must be decreased by
a factor of 5. We find that a model in which the inner galaxy is dominated by
advective escape and the outer galaxy by diffusive one fits the data well.
Three-dimensional modeling of cosmic-ray transport in the face-on galaxy M51
allows for conclusions about the strength of the outflow of such galaxies by
quantifying the need for a wind in the description of the cosmic-ray
signatures. This opens up the possibility of investigating galactic winds in
face-on galaxies in general.
Indirect observations of the cosmic-ray electron (CRE) distribution via
synchrotron emission is crucial for deepening the understanding of the CRE
transport in the interstellar medium, and in investigating the role of galactic
outflows. In this paper, we quantify the contribution of diffusion and
advection dominated transport of cosmic-ray electrons in the galaxy M51
considering relevant energy loss processes. We use recent measurement from M51
that allow for the derivation of the diffusion coefficient, the star formation
rate, and the magnetic field strength. With this input, we solve the 3D
transport equation numerically including the spatial dependence as provided by
the measurements, using the open-source transport framework CRPropa (v3.1). We
include three-dimensional transport (diffusion and advection), and the relevant
loss processes. We find that the data can be described well with the parameters
from recent measurements. For the best fit, it is required that the wind
velocity, following from the observed star formation rate, must be decreased by
a factor of 5. We find that a model in which the inner galaxy is dominated by
advective escape and the outer galaxy by diffusive one fits the data well.
Three-dimensional modeling of cosmic-ray transport in the face-on galaxy M51
allows for conclusions about the strength of the outflow of such galaxies by
quantifying the need for a wind in the description of the cosmic-ray
signatures. This opens up the possibility of investigating galactic winds in
face-on galaxies in general.
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