Detection of vortex tubes in solar granulation from observations with Sunrise

• Published in: arXiv.org
• Main Authors: Steiner, O, Franz, M, N Bello Gonzalez, Nutto, Ch, Rezaei, R, V Martinez Pillet, Bonet Navarro, J A, J C del Toro Iniesta, Domingo, V, Solanki, S K, Knolker, M, Schmidt, W, Barthol, P, Gandorfer, A
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 23.09.2010
• Subjects: Computer simulation; Convection; Granular materials; Granulation; Paths; Physics - Solar and Stellar Astrophysics; Solar granulation; Solar surface; Substructures; Sunrise; Tubes; Vortices
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1009.4723

We have investigated a time series of continuum intensity maps and corresponding Dopplergrams of granulation in a very quiet solar region at the disk center, recorded with the Imaging Magnetograph eXperiment (IMaX) on board the balloon-borne solar observatory Sunrise. We find that granules frequently show substructure in the form of lanes composed of a leading bright rim and a trailing dark edge, which move together from the boundary of a granule into the granule itself. We find strikingly similar events in synthesized intensity maps from an ab initio numerical simulation of solar surface convection. From cross sections through the computational domain of the simulation, we conclude that these `granular lanes' are the visible signature of (horizontally oriented) vortex tubes. The characteristic optical appearance of vortex tubes at the solar surface is explained. We propose that the observed vortex tubes may represent only the large-scale end of a hierarchy of vortex tubes existing near the solar surface.