The magnetic fields of our Milky Way galaxy are the main agent for transporting cosmic rays. In the last decade, much new knowledge has been gained from measurements of the Galactic magnetic fields. In the Galactic disk, from the RMs of a large number of newly discovered pulsars, the large-scale magnetic fields along the spiral arms have been delineated in a much larger region than ever before, with alternating directions in the arm and interarm regions. The toroidal fields in the Galactic halo were revealed to have opposite directions below and above the Galactic plane, which is an indication of an A0 mode dynamo operating in the halo. The strength of large-scale fields obtained from pulsar RM data has been found to increase exponentially towards the Galactic center. Compared to the steep Kolmogorov spectrum of magnetic energy at small scales, the large-scale magnetic fields show a shallow broken spatial magnetic energy spectrum.
Nuclear Physics B Proceedings Supplements
- Pub Date:
- January 2008
- Astrophysics - Galaxy Astrophysics
- 8 pages, 4 figures. Invited Talk at XIV International Symposium on Very High Energy Cosmic Ray Interactions, WeiHai, China 15-22 Aug 2006