Dual Flows and Oscillations in the Sunspot Transition Region

Abstract

New knowledge about sunspot transition region lines that deviate significantly from a Gaussian shape are presented. Attention is given to ``multiple flows,'' a line profile phenomenon in which two or more distinct velocities are observed within the same spatial resolution element. We observe line profiles that are well represented by two Gaussian line components in the N V λ1242 and O V λ629 lines and introduce the notation ``dual flow.'' We have detected transition region oscillations in one of the line components in the dual-flow events.