Non-LTE Inversion of Spectropolarimetric and Spectroscopic Observations of a Small Active-region Filament Observed at the VTT

摘要

An active region mini-filament was observed by VTT simultaneously in the He I 10830 ? triplet by the TIP 1 spectropolarimeter, in Ha by the TESOS Fabry-Pérot interferometer, and in Ca II 8542 A by the VTT spectrograph. The spectropolarimetric data were inverted using the HAZEL code and Ha profiles were modelled solving a NLTE radiative transfer in a simple isobaric and isothermal 2D slab irradiated both from bottom and sides. It was found that the mini-filament is composed of horizontal fluxtubes, along which the cool plasma of T ~ 10000 K can flow by very large - even supersonic - velocities.