Abstract
ABSTRACT Empirically, the X-ray luminosity L X from M dwarfs has been found to have an upper limit of about 0.2% of the bolometric flux L bol. In the limit where magnetic fields in M dwarfs are generated in equipartition with convective motions, we use stellar models to calculate the energy flux of Alfvén waves F A as a function of depth in the sub-surface convection zone. Since Alfvén waves have the optimal opportunity for wave modes to reach the corona, we suggest that F A sets an upper limit on the mechanical flux F mech which causes coronal heating. This suggestion accounts quantitatively for the “saturated” values of L X/L bol which have been reported empirically for M dwarfs.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
