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Abstract: The magnetic structure in the Galactic disk, the Galactic center and theGalactic halo can be delineated more clearly than ever before. In the Galacticdisk, the magnetic structure has been revealed by starlight polarization within2 or 3 kpc of the Solar vicinity, by the distribution of the Zeeman splittingof OH masers in two or three nearby spiral arms, and by pulsar dispersionmeasures and rotation measures in nearly half of the disk. The polarizedthermal dust emission of clouds at infrared, mm and submm wavelengths and thediffuse synchrotron emission are also related to the large-scale magnetic fieldin the disk. The rotation measures of extragalactic radio sources at lowGalactic latitudes can be modeled by electron distributions and large-scalemagnetic fields. The statistical properties of the magnetized interstellarmedium at various scales have been studied using rotation measure data andpolarization data. In the Galactic center, the non-thermal filaments indicatepoloidal fields. There is no consensus on the field strength, maybe mG, maybetens of uG. The polarized dust emission and much enhanced rotation measures ofbackground radio sources are probably related to toroidal fields. In theGalactic halo, the antisymmetric RM sky reveals large-scale toroidal fieldswith reversed directions above and below the Galactic plane. Magnetic fieldsfrom all parts of our Galaxy are connected to form a global field structure.More observations are needed to explore the untouched regions and delineate howfields in different parts are connected.

Author: J. L. Han NAOC


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