2024/04/25 by Ningning Guo, Jianfu Zhang, Guo, Ning-Ning +7 · 1 citation
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Geomagnetism and Paleomagnetism Studies #High Energy Astrophysical Phenomena (astro-ph.HE) #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2404.16310
openalex publication_date 2024/04/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Since synchrotron polarization fluctuations are related to the fundamental properties of the magnetic field, we propose the polarization intensity variance to measure the Galactic interstellar medium (ISM) magnetization. We confirm the method's applicability by comparing it with the polarization angle dispersion and its reliability by measuring the underlying Alfvénic Mach number of MHD turbulence. With the finding of the power-law relation of A ∝ M\rm A2 between polarization intensity variance A and Alfvénic Mach number M\rm A, we apply the new technique to the Canadian Galactic Plane Survey (CGPS) data, achieving Alfvénic Mach number of the Galactic ISM. Our results show that the low-latitude Galactic ISM is dominated by sub-Alfénic turbulence, with M\rm A approximately between 0.5 and 1.0.