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arXiv · 1712.06829

Inference of chromospheric magnetic fields in a sunspot derived from spectropolarimetry of Ca II 8542 A

Ali G. A. Abdelkawy·Abdelrazek M. K. Shaltout·M. M. Beheary·T. A. Schad
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Abstract

We analyze spectropolarimetric observations of the chromospheric Ca II 8542 A line taken by the Interferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope. The data were observed on 2012 January 29 for the NOAA active region 11408. Adopting the center-of-gravity (COG) approach we obtain the line-of-sight (LOS) field strength for the chromospheric IBIS data of Ca II 8542 A line. The LOS strength of the magnetic field is determined in the target active region inside a field of view 45 x 95 arcsec. The LOS field values were found to be increase up to 800 G inside the umbral region and decrease systematically toward the edges of a sunspot. Under the weak field approximation (WFA), the horizontal, vertical magnetic field components and azimuthal field vector are obtained.

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Ali G. A. Abdelkawy, Abdelrazek M. K. Shaltout, M. M. Beheary, T. A. Schad. 2017-12-19. Inference of chromospheric magnetic fields in a sunspot derived from spectropolarimetry of Ca II 8542 A. https://arxiv.org/abs/1712.06829

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