Institut national de recherche scientifique français Univerité Pierre et Marie Curie Université Paris Diderot - Paris 7

Small-scale structures in the upper atmosphere of the Sun

jeudi 22 février 2018, par Krzysztof Barczynski (LESIA)

Mercredi 28 fĂ©vrier 2018 à 11h00 , Lieu : Salle de rĂ©union du bâtiment 16

Numerous small-scale structures (sizes of the order of megameters) constitute the background for the large-scale structures in the solar atmosphere. Their large number suggests that they play an important role in the energy transport and the magnetic structuring in the solar atmosphere.

Properties of the small-scale structures in the solar atmosphere will be discussed. Particular attention is given to miniature loops (with a length of approximately 1 Mm) observed for the first time at coronal temperature (> 1 MK), and their relation between the emission of the small-scale structures and the underlying magnetic field. We also make a focus on the structures which are unresolved by modern instruments. We investigate the relation between emission from the different part of the solar atmosphere and underlying magnetic field. This study provides a statistical proxy of the properties of unresolved small-scale structures. We present study based on UV and EUV observation (images, spectra) with a combination of photospheric magnetic field maps.

We show that miniature loops are a small-scale version of the hot coronal loop. We also find how the correlation and intensity-magnetic field relations (presented in our study as a power-law) change moving up from the upper photosphere to the transition region and discuss possible interpretations of obtained dependencies.