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Diagnostics of Coronal Heating in Solar Active Regions

Published online by Cambridge University Press:  26 May 2016

A. Fludra  and
J. Ireland
A. Fludra
Affiliation:
CCLRC Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
J. Ireland
Affiliation:
L3com. Analytics Corp., NASA GSFC, Greenbelt, MD 20771, USA

Abstract

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We study the relationship between EUV spectral line intensities and the photospheric magnetic field in solar active regions, using magnetograms from SOHO-MDI and EUV spectra of the Fe XVI 360.8 Â line (2 × 106 K) and the O V 629.7 A line (220,000 K) from the Coronal Diagnostic Spectrometer on SOHO, recorded for several active regions. We overlay and compare spatial patterns of the O V emission and the magnetic flux concentrations, with a 4″ x 4″ spatial resolution, and search for a relationship between the local O V line intensity and the photospheric magnetic flux density in each active region. While this dependence exhibits a certain amount of scatter, it can be represented by a power law fit. The average power index from all regions is 0.7 ± 0.2. Applying static loop models, we derive the dependence of the heating rate on the magnetic flux density, Eh ∝ B0.8, and compare it to the dependence predicted by the coronal heating models.

Type
Part 9: Heating of Solar and Stellar Coronae
Information
Symposium - International Astronomical Union , Volume 219: Stars as Suns : Activity, Evolution and Planets , 2004 , pp. 478 - 482
Copyright
Copyright © Astronomical Society of the Pacific 2004 

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