Horizontal velocities in the solar photosphere |
| |
Authors: | Dainis Dravins |
| |
Affiliation: | 1. Lund Observatory, S-22224, Lund, Sweden
|
| |
Abstract: | Horizontal macroscopic velocities V hor in the photosphere are studied. High-resolution spectrograms of quiet regions are analyzed for center-limb variation of rms Doppler shifts. The data are treated to assure that the observed velocities refer to constant size volumes on the Sun (800 × × 3000 × 250 km), independent of μ. Using known height variation of vertical velocities and calculated line formation heights, the height dependence of 〈V hor〉 is obtained. From a value around 450 m s?1 it decreases rapidly with increasing height. To study also small-scale velocities, the time evolution of subarcsecond size elements in the photospheric network (solar filigree) is studied on filtergrams. It is concluded that they show proper motions implying 〈V hor〉 about 1 km s?1. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|