https://doi.org/10.1051/epjconf/20111606013
Mapping radio emitting-region on low-mass stars and brown dwarfs
1 Armagh Observatory, College Hill, Armagh BT61 9DG, N. Ireland
2 Centre for Astronomy, National University of Ireland, Galway, Ireland
3 The Department of Adult and Continuing Education, University of Glasgow, Scotland
a e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Abstract
Strong magnetic activity in ultracool dwarfs (UCDs, spectral classes later than M7) have emerged from a number of radio observations, including the periodic beams. The highly (up to 100%) circularly polarized nature of the emission point to an effective amplification mechanism of the high-frequency electromagnetic waves – the electron cyclotron maser (ECM) instability. Several anisotropic velocity distibution models of electrons, including the horseshoe distribution, ring shell distribution and the loss-cone distribution, are able to generate the ECM instability. A magnetic-field-aligned electric potential would play an significant role in the ECM process. We are developing a theoretical model in order to simulate ECM and apply this model to map the radio-emitting region on low-mass stars and brown dwarfs.
© Owned by the authors, published by EDP Sciences, 2011
