Simultaneous Stokes-V diagnostic of a Sunspot using Mg b and Fe I lines
Abstract
Simultaneous observations of Stokes profiles in photospheric Fei (630.15 nm and 630.25 nm) and chromospheric Mgi b1 and b2 (518.4 nm and 517.3 nm) lines over a sunspot are presented. Observations were carried out using the Advanced Stokes Polarimeter of HAO/NSO, VTT, SacPeak, U.S.A. The Stokes-V amplitude asymmetries for these lines are analyzed. The values of amplitude asymmetry in Mgb lines are negative in disk-center-side penumbra while they are positive in limb-side penumbra. This trend is similar in nature to photospheric Fei line observations. Further, the spatial distribution of Stokes-V asymmetry is analyzed using Net Circular Polarization (NCP) maps. The chromospheric and photospheric NCP maps are different in many aspects. These observations with longitudinal magnetic field, estimated using weak field approximation, are discussed in this paper.
- Publication:
-
Solar Physics
- Pub Date:
- October 2003
- DOI:
- 10.1023/A:1027369902136
- Bibcode:
- 2003SoPh..217..119G
- Keywords:
-
- Magnetic Field;
- Spatial Distribution;
- Circular Polarization;
- Field Approximation;
- Weak Field