Velocity Structure of Jets in a Coronal Hole
Shibata, Kazunari; Warren, Harry P.; Hara, Hirohisa; Culhane, Len; Kamio, Suguru; Watanabe, Tetsuya; Matsuzaki, Keiichi
Japan, United Kingdom, United States
Abstract
The velocity structures of jets in a coronal hole have been derived for the first time. Hinode observations revealed the existence of many bright points in coronal holes. They are loop-shaped and sometimes associated with coronal jets. Spectra obtained with the Extreme-ultraviolet Imaging Spectrometer aboard Hinode were analyzed to infer the Doppler velocity of bright loops and jets in a coronal hole of the north polar region. Elongated jets above bright loops are found to be blue-shifted by 30kms-1 at maximum, while foot points of bright loops are red-shifted. Blue-shifts detected in coronal jets are interpreted as being upflows produced by magnetic reconnection between emerging flux and the ambient field in the coronal hole.