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dc.date.accessioned2020-03-20T19:16:57Z
dc.date.available2020-03-20T19:16:57Z
dc.date.created2019-08-27T11:42:50Z
dc.date.issued2019
dc.identifier.citationVissers, Gregal Joan Maria de la Cruz Rodriguez, Jaime Libbrecht, Tine Rouppe van der Voort, Luc Scharmer, Göran B. Carlsson, Mats . Dissecting bombs and bursts: Non-LTE inversions of low-atmosphere reconnection in SST and IRIS observations. Astronomy and Astrophysics. 2019, 627
dc.identifier.urihttp://hdl.handle.net/10852/74116
dc.description.abstractEllerman bombs and UV bursts are transient brightenings that are ubiquitously observed in the lower atmospheres of active and emerging flux regions. As they are believed to pinpoint sites of magnetic reconnection in reconfiguring fields, understanding their occurrence and detailed evolution may provide useful insight into the overall evolution of active regions. Here we present results from inversions of SST/CRISP and CHROMIS, as well as IRIS data of such transient events. Combining information from the Mg II h & k, Si IV, and Ca II 8542 Å and Ca II H & K lines, we aim to characterise their temperature and velocity stratification, as well as their magnetic field configuration. We find average temperature enhancements of a few thousand kelvin, close to the classical temperature minimum and similar to previous studies, but localised peak temperatures of up to 10 000–15 000 K from Ca II inversions. Including Mg II appears to generally dampen these temperature enhancements to below 8000 K, while Si IV requires temperatures in excess of 10 000 K at low heights, but may also be reproduced with secondary temperature enhancements of 35 000–60 000 K higher up. However, reproducing Si IV comes at the expense of overestimating the Mg II emission. The line-of-sight velocity maps show clear bi-directional jet signatures for some events and strong correlation with substructure in the intensity images in general. Absolute line-of-sight velocities range between 5 and 20 km s−1 on average, with slightly larger velocities towards, rather than away from, the observer. The inverted magnetic field parameters show an enhancement of the horizontal field co-located with the brightenings at heights similar to that of the temperature increase. We are thus able to largely reproduce the observational properties of Ellerman bombs with the UV burst signature (e.g. intensities, profile asymmetries, morphology, and bi-directional jet signatures), with temperature stratifications peaking close to the classical temperature minimum. Correctly modelling the Si IV emission in agreement with all other diagnostics is however an outstanding issue and remains paramount in explaining its apparent coincidence with Hα emission. Fine-tuning the approach (accounting for resolution differences, fitting localised temperature enhancements, and/or performing spatially coupled inversions) is likely necessary in order to obtain better agreement between all considered diagnostics. © ESO 2019
dc.languageEN
dc.publisherEDP Sciences
dc.titleDissecting bombs and bursts: Non-LTE inversions of low-atmosphere reconnection in SST and IRIS observations
dc.typeJournal article
dc.creator.authorVissers, Gregal Joan Maria
dc.creator.authorde la Cruz Rodriguez, Jaime
dc.creator.authorLibbrecht, Tine
dc.creator.authorRouppe van der Voort, Luc
dc.creator.authorScharmer, Göran B.
dc.creator.authorCarlsson, Mats
cristin.unitcode185,15,3,40
cristin.unitnameRosseland senter for solfysikk
cristin.ispublishedtrue
cristin.fulltextoriginal
cristin.qualitycode2
dc.identifier.cristin1719051
dc.identifier.bibliographiccitationinfo:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Astronomy and Astrophysics&rft.volume=627&rft.spage=&rft.date=2019
dc.identifier.jtitleAstronomy and Astrophysics
dc.identifier.volume627
dc.identifier.pagecount25
dc.identifier.doihttps://doi.org/10.1051/0004-6361/201833560
dc.identifier.urnURN:NBN:no-77227
dc.type.documentTidsskriftartikkel
dc.type.peerreviewedPeer reviewed
dc.source.issn0004-6361
dc.identifier.fulltextFulltext https://www.duo.uio.no/bitstream/handle/10852/74116/2/aa33560-18.pdf
dc.type.versionPublishedVersion
cristin.articleidA101
dc.relation.projectNFR/262622
dc.relation.projectNFR/250810
dc.relation.projectNOTUR/NORSTORE/NN2834K
dc.relation.projectNOTUR/NORSTORE/nn2834k


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