Hostname: page-component-848d4c4894-wg55d Total loading time: 0 Render date: 2024-05-15T10:26:44.517Z Has data issue: false hasContentIssue false
  • English
  • Français

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

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

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 

References

Fisher, G.H., Longcope, D.W., Metcalf, T.R., & Pevtsov, A.A. 1998, ApJ, 508, 885.Google Scholar
Fludra, A., & Ireland, J. 2003a, A&A, 398, 297.Google Scholar
Fludra, A., & Ireland, J. 2003b, In: “The Future of Cool-Star Astrophysics”, Eds. Brown, A., Harper, G. M., & Ayres, T. R.. Proceedings of 12th Cambridge Workshop on Cool Stars, Stellar Systems, & the Sun, p. 220 (http://origins.Colorado.EDU/cs12/proceedings/oral/tuesday/fludraproc.html).Google Scholar
Fludra, A., Ireland, J., del Zanna, G., & Thompson, W. T. 2002a, Adv. Space Res., Vol. 29, Issue 3, p. 361.Google Scholar
Fludra, A., & Ireland, J., 2002b, In: SOLMAG 2002. Proceedings of the Magnetic Coupling of the Solar Atmosphere Euroconference and IAU Colloquium 188, ESA Publications Division, ESA SP-505, p. 405.Google Scholar
Fludra, A., & Ireland, J., In: Proceedings of the SOHO 11 Symposium on From Solar Min to Max: Half a Solar Cycle with SOHO, ESA Publications Division, 2002, ESA SP-508, p. 267.Google Scholar
Gurman, J.B., Withbroe, G.L., & Harvey, J.W. 1974, Solar Phys., 34, 105.Google Scholar
Mandrini, C.H., Demoulin, P., & Klimchuk, J.A. 2000, ApJ, 530, 999.Google Scholar
Martens, P.C.H., Kankelborg, C.C., & Berger, T.E. 2000, ApJ, 537, 471.Google Scholar
Schrijver, C.J., 1987, A&A, 180, 241.Google Scholar
Schrijver, C.J., & Aschwanden, M.J. 2002, ApJ, 566, 1147.Google Scholar
Yashiro, S., & Shibata, K. 2001, ApJ, 550, L113.Google Scholar