Identification of plasma modes in Galactic turbulence with synchrotron polarization

Journal
Date Issued
2020
Author(s)
•
Chepurnov, Alexey
•
Yan, Huirong
•
Makwana, Kirit
•
Santos-Lima, Reinaldo
•
Appleby, Sarah
DOI
Abstract
Magnetohydrodynamic turbulence is a ubiquitous and fundamental ingredient underlying many astrophysical phenomena. The multiphase nature of the interstellar medium and the diversity of driving mechanisms give rise to spatial variation of turbulence properties, particularly plasma properties. There has been no observational diagnosis of the plasma modes beyond the solar system so far. Here we report the identification of different plasma modes in various Galactic environments, including active star-forming zones and supernova remnants, on the basis of our synchrotron polarization analysis. The observed high degree of consistency between the γ-ray excess in the Cygnus cocoon and the location of magnetosonic modes provides strong observational evidence for the long-advocated theory that magnetosonic modes dominate the cosmic ray (CR) scattering and acceleration. Our results open up a new avenue for the study of interstellar turbulence and demonstrate the indispensability of accounting for their plasma properties in all the relevant processes, including CR transport and star formation.
Volume
4
Issue
10
Start page
1001
Uri
Url
Issn Identifier
2397-3366
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

s41550-020-1093-4.pdf

Description
[Administrators only]
Size

3.38 MB

Format

Adobe PDF

Checksum (MD5)

3d2bfa2a2b36878965a7d98aba1f6e78

Loading...
Thumbnail Image
Name

article_nat.pdf

Description
Preprint
Size

1.14 MB

Format

Adobe PDF

Checksum (MD5)

11d0a1da6110fa8abce8db58f2500024