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dc.contributor.authorKleint, L.
dc.contributor.authorAntolin, P.
dc.contributor.authorTian, H.
dc.contributor.authorJudge, P.
dc.contributor.authorTesta, P.
dc.contributor.authorDe Pontieu, B.
dc.contributor.authorMartínez-Sykora, J.
dc.contributor.authorReeves, K. K.
dc.contributor.authorWuelser, J. P.
dc.contributor.authorMcKillop, S.
dc.contributor.authorSaar, S.
dc.contributor.authorCarlsson, M.
dc.contributor.authorBoerner, P.
dc.contributor.authorHurlburt, N.
dc.contributor.authorLemen, J.
dc.contributor.authorTarbell, T. D.
dc.contributor.authorTitle, A.
dc.contributor.authorGolub, L.
dc.contributor.authorHansteen, V.
dc.contributor.authorJaeggli, S.
dc.contributor.authorKankelborg, C.
dc.date.accessioned2017-02-13T17:30:09Z
dc.date.available2017-02-13T17:30:09Z
dc.date.issued2014-06-27
dc.identifier.citationKleint , L , Antolin , P , Tian , H , Judge , P , Testa , P , De Pontieu , B , Martínez-Sykora , J , Reeves , K K , Wuelser , J P , McKillop , S , Saar , S , Carlsson , M , Boerner , P , Hurlburt , N , Lemen , J , Tarbell , T D , Title , A , Golub , L , Hansteen , V , Jaeggli , S & Kankelborg , C 2014 , ' Detection of supersonic downflows and associated heating events in the transition region above sunspots ' , Astrophysical Journal Letters , vol. 789 , no. 2 , L42 . https://doi.org/10.1088/2041-8205/789/2/L42en
dc.identifier.issn2041-8205
dc.identifier.otherPURE: 248969928
dc.identifier.otherPURE UUID: 62a0ecf5-5e44-463a-bd98-b3ca01a53025
dc.identifier.otherBibCode: 2014ApJ...789L..42K
dc.identifier.otherScopus: 84903955110
dc.identifier.urihttps://hdl.handle.net/10023/10282
dc.description.abstractInterface Region Imaging Spectrograph data allow us to study the solar transition region (TR) with an unprecedented spatial resolution of 0″33. On 2013 August 30, we observed bursts of high Doppler shifts suggesting strong supersonic downflows of up to 200 km s–1 and weaker, slightly slower upflows in the spectral lines Mg II h and k, C II 1336, Si IV 1394 Å, and 1403 Å, that are correlated with brightenings in the slitjaw images (SJIs). The bursty behavior lasts throughout the 2 hr observation, with average burst durations of about 20 s. The locations of these short-lived events appear to be the umbral and penumbral footpoints of EUV loops. Fast apparent downflows are observed along these loops in the SJIs and in the Atmospheric Imaging Assembly, suggesting that the loops are thermally unstable. We interpret the observations as cool material falling from coronal heights, and especially coronal rain produced along the thermally unstable loops, which leads to an increase of intensity at the loop footpoints, probably indicating an increase of density and temperature in the TR. The rain speeds are on the higher end of previously reported speeds for this phenomenon, and possibly higher than the free-fall velocity along the loops. On other observing days, similar bright dots are sometimes aligned into ribbons, resembling small flare ribbons. These observations provide a first insight into small-scale heating events in sunspots in the TR.
dc.format.extent7
dc.language.isoeng
dc.relation.ispartofAstrophysical Journal Lettersen
dc.rights© 2014. The American Astronomical Society. All rights reserved. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at: https://dx.doi.org/10.1088/2041-8205/789/2/L42en
dc.subjectSun: transition regionen
dc.subjectSunspotsen
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.subject.lccQBen
dc.subject.lccQCen
dc.titleDetection of supersonic downflows and associated heating events in the transition region above sunspotsen
dc.typeJournal articleen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews. Applied Mathematicsen
dc.identifier.doihttps://doi.org/10.1088/2041-8205/789/2/L42
dc.description.statusPeer revieweden
dc.identifier.urlhttp://adsabs.harvard.edu/abs/2014ApJ...789L..42Ken


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