The coronal convection

Дата и время публикации : 2011-01-12T13:58:55Z

Авторы публикации и институты :
Werner Curdt
Hui Tian
Eckart Marsch

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 8 pages, 5 figures, accepted for publication in Cent. Eur. Astrophys. Bull
Первичная категория: astro-ph.SR

Все категории : astro-ph.SR

Краткий обзор статьи: We study the hydrogen Lyman emission in various solar features – now including Lyman-alpha observations free from geocoronal absorption – and investigate statistically the imprint of flows and of the magnetic field on the line profile and radiance distribution. As a new result, we found that in Lyman-alpha rasters locations with higher opacity cluster in the cell interior, while the network has a trend to flatter profiles. Even deeper self reversals and larger peak distances were found in coronal hole spectra. We also compare simultaneous Lyman-alpha and Lyman-beta profiles. There is an obvious correspondence between asymmetry and redshift for both lines, but, most surprisingly, the asymmetries of Lyman-alpha and Lyman-beta are opposite. We conclude that in both cases downflows determine the line profile, in case of Lyman-alpha by absorption and in the case of Ly-beta by emission. Our results show that the magnetically structured atmosphere plays a dominating role in the line formation and indicate the presence of a persisting downflow at both footpoints of closed loops. We claim that this is the manifestation of a fundamental mass transportation process, which Foukal back in 1978 introduced as the ‘coronal convection’.

Category: Physics