Turbulent Magnetic Field Generation in Rotating Stars

Observationally, it has been found that magnetic activity is a strong function of rotation rate. The connection between rotation and dynamo-generated fields is not well understood, however. The typical interface dynamo theory applied to the Sun to describe its activity cycle assumes the existence of a velocity shear layer. Such a model is inappropriate for fully convective stars that are nevertheless active, such as late-type M and L stars and pre-main sequence T Tauri stars; in these stars a turbulent dynamo is generally believed to be the mechanism of magnetic field generation. We investigate the connection between observed activity behavior and magnetic field generation in fully convective stars through a series of simulations of the turbulent dynamo. The simulations were performed in a Cartesian domain using ANMHD, a 3D MHD anelastic code. We compare the resulting magnetic topologies for a series of Rossby numbers and comment on the implications for the sizes of coronal loops and activity levels.