Talk abstract

Signatures of magnetic reconnection occurring in a small-scale emerging flux region inferred by high-resolution multi-wavelength observations
S. L. Guglielmino, L. R. Bellot Rubio, F. Zuccarello, G. Aulanier, S. Vargas Domínguez, S. Kamio


Several phenomena may occur in different layers of the solar atmosphere when the new magnetic flux emerges and interacts with the pre-existing ambient field. The appearance of surges and brightenings during flux emergence is a clear evidence of the magnetic reconnection process, at work in the emergence site because of the rearrangement in the magnetic topology. We analyze a small-scale flux emergence episode, occurred in NOAA 10971, observed simultaneously by the Hinode satellite and the Swedish Solar Telescope in La Palma Island. G-band, Hα, and Ca II H images, together with Fe I and Na I magnetograms, EUV raster scans, and XRT filtergrams show that the emerging region is associated with a Hα chromospheric surge and Ca II H, Hα, EUV and X-ray brightenings. We find also magnetic flux cancellation occurring in the lower atmospheric layers. We discuss this event within the framework of the low-altitude magnetic reconnection model. At this purpose, we also present a series of force-free extrapolations, calculated with the FROMAGE code, which show that the emergence site spatially coincides with a 3D null point, from which a spine originates. Such a magnetic configuration is comparable with the structures observed in the different atmospheric layers.