Growth rate of magnetic field during star burst phase in a galaxy

Ko Chung-Ming, cmko@astro.ncu.edu.tw, Institute of Astronomy, National Central University, Taiwan, Taiwan, China

Abstract
During an active star formation phase in a galaxy, its turbulent level is expected to increase naturally. Consequently its magnetic field will be increased by turbulent dynamo process. We point out that the thickness of the disk, and thus the dynamo region, is sensitive to the turbulent level. Bear this in mind, we examine the linear growth rate of three dynamo models, namely, the alpha-omega, alpha-square and alpha-square-omega dynamos. It is interesting to note that the growth rate is not necessary monotonic to turbulence level even in the linear regime. Moreover, the dependence of the growth rate on turbulent level is quite different for the three dynamos.