Peculiarities of the plasma mechanism of radio emission from late-type stars

The plasma mechanism of radio emission in the coronas of late-type stars is shown to be considerably more efficient than that in the solar corona beca use of the high plasma temperature in their magnetic arches. This is attrib utable to an increase in the length of plasma-wave conversion into electrom agnetic waves and a decrease in the optical depth of collisional wave absor ption. Magnetic-arch filamentation results in a decrease in the intensity o f the fundamental-tone radio emission and in the relative dominance of the second-harmonic radio emission. The efficiency of the fundamental-tone radi o emission increases with plasma density in a coronal arch. The plasma mech anism accounts for the high brightness temperature of the flare radio emiss ion from stars (greater than or equal to 10(14) K). (C) 2000 MAIK "Nauka/In terperiodica ".