shelyag-signaturesofquietsun-2018.pdf (9.1 MB)
Signatures of quiet Sun reconnection events in Ca II, Hα, and Fe I
journal contribution
posted on 2018-09-01, 00:00 authored by J Shetye, Sergiy ShelyagSergiy Shelyag, A L Reid, E Scullion, J G Doyle, T D ArberWe use observations of quiet Sun (QS) regions in the Hα 6563 Å, CaII 8542 Å, and FeI 6302 Å lines. We observe brightenings in the wings of the Hα and CaII combined with observations of the interacting magnetic concentrations observed in the Stokes signals of Fe I. These brightenings are similar to Ellerman bombs (EBs), i.e. impulsive bursts in the wings of the Balmer lines that leave the line cores unaffected. Such enhancements suggest that these events have similar formation mechanisms to the classical EBs found in active regions, with the reduced intensity enhancements found in the QS regions due to a weaker feeding magnetic flux. The observations also show that the quiet Sun Ellerman bombs are formed at a higher height in the upper photosphere than the photospheric continuum level. Using simulations, we investigate the formation mechanism associated with the events and suggest that these events are driven by the interaction of magnetic field lines in the upper photospheric regions. The results of the simulation are in agreement with observations when comparing the light curves, and in most cases, we found that the peak in the CaII 8542 Å wing occurred before the peak in Hα wing. Moreover, in some cases, the line profiles observed in CaII are asymmetrical with a raised core profile. The source of heating in these events is shown by theMURaM simulations and is suggested to occur 430 km above the photosphere.
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Journal
Monthly notices of the Royal Astronomical SocietyVolume
479Issue
3Pagination
3274 - 3287Publisher
Oxford University PressLocation
Oxford, Eng.Publisher DOI
ISSN
0035-8711eISSN
1365-2966Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2018, The Author(s)Usage metrics
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