The granular magnetic field as observed with THEMIS
Résumé
The search for correlation along the slit in THEMIS spectropolarimetric observations of a quiet region shows a positive autocorrelation of the magnetic field direction with a pixel size of 0.45 arcsec. Accordingly, the magnetic field appears as partially resolved with such a pixel size. Further spectropolarimetric observations have been performed by scanning a quiet region with THEMIS tip-tilt ON, in order to investigate a possible relationship between the granulation and the magnetic field vector which is known in each pixel of this observation (pixel size of 0.25 arcsec). As a result, we see a very clear correlation between the granulation observed in the continuum and the longitudinal velocity field observed via the Doppler effect, but the granulation and the magnetic field vector (strength and direction) appear us as uncorrelated, by looking at their respective maps. These quantities (velocity and magnetic field) have been derived from spectropolarimetric observations of the Fe I 6302.5 line, to which UNNOFIT inversion has been applied to derive the magnetic field vector.