ESTIMATION OF MAGNETIC FIELD STRENGTH IN THE TURBULENT WARM IONIZED MEDIUM

Journal Article · Sun Nov 01 04:00:00 EST 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/705/1/L86· OSTI ID:21378323

Qingwen, Wu; Kim, Jongsoo ^[1]; Ryu, Dongsu; Cho, Jungyeon ^[2]; Alexander, Paul ^[3]

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1. Korea Astronomy and Space Science Institute, 61-1, Hwaam-Dong, Yuseong-Gu, Daejeon 305-348 (Korea, Republic of)
2. Department of Astronomy and Space Science, Chungnam National University, Daejeon 305-764 (Korea, Republic of)
3. Astrophysics Group, Cavendish Laboratory, Cambridge University, JJ Thompson Avenue, Cambridge CB3 0HE (United Kingdom)

We studied Faraday rotation measure (RM) in turbulent media with the rms Mach number of unity, using isothermal, magnetohydrodynamic turbulence simulations. Four cases with different values of initial plasma beta were considered. Our main findings are as follows. (1) There is no strong correlation between the fluctuations of magnetic field strength and gas density. So the magnetic field strength estimated with RM/DM (DM is the dispersion measure) correctly represents the true mean strength of the magnetic field along the line of sight. (2) The frequency distribution of RMs is well fitted to the Gaussian. In addition, there is a good relation between the width of the distribution of RM/RM-bar (RM-bar is the average value of RMs) and the strength of the regular field along the line of sight; the width is narrower, if the field strength is stronger. We discussed the implications of our findings in the warm ionized medium where the Mach number of turbulent motions is around unity.

• OSTI ID: 21378323
• Journal Information: Astrophysical Journal (Online), Journal Name: Astrophysical Journal (Online) Journal Issue: 1 Vol. 705; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
DIMENSIONLESS NUMBERS
FARADAY EFFECT
FLUID MECHANICS
HYDRODYNAMICS
MACH NUMBER
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MECHANICS
PLASMA
SIMULATION
TURBULENCE
VELOCITY