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Flow and magnetic field properties in the trailing sunspots of active region NOAA 12396
Author(s) -
Verma M.,
Denker C.,
Böhm F.,
Balthasar H.,
Fischer C. E.,
Kuckein C.,
Bello González N.,
Berkefeld T.,
Collados M.,
Diercke A.,
Feller A.,
González Manrique S. J.,
Hofmann A.,
Lagg A.,
Nicklas H.,
Orozco Suárez D.,
Pator Yabar A.,
Rezaei R.,
Schlichenmaier R.,
Schmidt D.,
Schmidt W.,
Sigwarth M.,
Sobotka M.,
Solanki S. K.,
Soltau D.,
Staude J.,
Strassmeier K. G.,
Volkmer R.,
von der Lühe O.,
Waldmann T.
Publication year - 2016
Publication title -
astronomische nachrichten
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 63
eISSN - 1521-3994
pISSN - 0004-6337
DOI - 10.1002/asna.201612447
Subject(s) - sunspot , spectrograph , physics , solar telescope , solar observatory , magnetic flux , astrophysics , magnetic field , flux (metallurgy) , photosphere , infrared , observatory , spectral line , geophysics , telescope , astronomy , quantum mechanics , materials science , metallurgy
Improved measurements of the photospheric and chromospheric three‐dimensional magnetic and flow fields are crucial for a precise determination of the origin and evolution of active regions. We present an illustrative sample of multiinstrument data acquired during a two‐week coordinated observing campaign in August 2015 involving, among others, the GREGOR solar telescope (imaging and near‐infrared spectroscopy) and the space missions Solar Dynamics Observatory (SDO) and Interface Region Imaging Spectrograph (IRIS). The observations focused on the trailing part of active region NOAA 12396 with complex polarity inversion lines and strong intrusions of opposite polarity flux. The GREGOR Infrared Spectrograph (GRIS) provided Stokes IQUV spectral profiles in the photospheric Si I λ 1082.7 nm line, the chromospheric He I λ 1083.0 nm triplet, and the photospheric Ca I λ 1083.9 nm line. Carefully calibrated GRIS scans of the active region provided maps of Doppler velocity and magnetic field at different atmospheric heights. We compare quick‐look maps with those obtained with the “Stokes Inversions based on Response functions” (SIR) code, which furnishes deeper insight into the magnetic properties of the region. We find supporting evidence that newly emerging flux and intruding opposite polarity flux are hampering the formation of penumbrae, i.e., a penumbra fully surrounding a sunspot is only expected after cessation of flux emergence in proximity to the sunspots. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)