The MSDP of THEMIS: Capabilities, first results and prospects

Abstract

We present some capabilities and results of the Multi Channel Subtractive Double Pass instrument of THEMIS. More details and references can be found at http://www.themis.iac.es. MSDP imaging spectropolarimetry is characterized by high space and time resolution. The spatial resolution is close to seeing limitations, and large areas of the Sun can be scanned within short time intervals. In the case of THEMIS, polarization measurements are possible. 2 Stokes parameters and 16 wavelengths of a line profile can be observed simultaneously in a 2D field of view. The scattered light is reduced by the use of the long predisperser as a first-pass spectrograph. Some results are presented for fine structures of the chromosphere and stratification of magnetic fields. The MSDP of THEMIS is very efficient to observe fast extended events, such as eruptive phenomena and mass ejections, in particular during coordinated campaigns with space instruments. General outlines of the data-processing are given. All codes are available at http://BASS2000.bagn.obs-mip.fr. In conclusion, we mention future prospects with respect to spatial and spectral resolution, large field-of-view, multi-line observations, and compatibility with other THEMIS observing modes.