Please use this identifier to cite or link to this item: http://hdl.handle.net/2248/8528
Title: Extreme-ultraviolet Polarimetric Diagnostics of the Solar Corona: The Hanle Effect of Ne VIII 770Å
Authors: Khan, Raveena
Gibson, Sarah E
Casini, Roberto
Nagaraju, K
Keywords: Solar corona
Polarimetry
Magnetohydrodynamics
Solar extreme ultraviolet emission
Issue Date: 10-Aug-2024
Publisher: American Astronomical Society
Citation: The Astrophysical Journal, Vol. 971, No. 1, 27
Abstract: Magnetic fields are the primary driver of the plasma thermodynamics in the upper solar atmosphere, especially in the corona. However, magnetic field measurements in the solar corona are sporadic, thereby limiting us from the complete understanding of physical processes occurring in the coronal plasma. In this paper, we explore the diagnostic potential of a coronal emission line in the extreme-ultraviolet, i.e., Ne viii 770 Å, to probe the coronal magnetic fields. We utilize 3D "Magnetohydrodynamic Algorithm outside a Sphere" models as input to the FORWARD code to model polarization in the Ne viii line produced as a result of resonance scattering, and we interpret its modification due to collisions and the magnetic fields through the Hanle effect. The polarization maps are synthesized both on the disk and off the limb. The variation of this polarization signal through the different phases of Solar Cycle 24 and the beginning phase of Solar Cycle 25 is studied in order to understand the magnetic diagnostic properties of this line owing to different physical conditions in the solar atmosphere. The detectability of the linear polarization signatures of the Hanle effect significantly improves with increasing solar activity, consistent with the increase in the magnetic field strength and the intensity of the mean solar brightness at these wavelengths. We finally discuss the signal-to-noise ratio requirements by considering realistic instrument designs.
Description: Open Access
Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
URI: http://hdl.handle.net/2248/8528
ISSN: 1538-4357
Appears in Collections:IIAP Publications



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