J/ApJ/759/141ivo://CDS.VizieR/J/ApJ/759/141doi:10.26093/cds/vizier.17590141CDSWarren H.P.Winebarger A.R.Brooks D.H.2014-09-04T19:51:00Z2014-08-22T12:22:35ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frthe-sunThe recent analysis of observations taken with the EUV Imaging Spectrometer and X-Ray Telescope instruments on Hinode suggests that well-constrained measurements of the temperature distribution in solar active regions can finally be made. Such measurements are critical for constraining theories of coronal heating. Past analysis, however, has suffered from limited sample sizes and large uncertainties at temperatures between 5 and 10MK. Here we present a systematic study of the differential emission measure distribution in 15 active region cores. We focus on measurements in the "inter-moss" region, that is, the region between the loop footpoints, where the observations are easier to interpret. To reduce the uncertainties at the highest temperatures we present a new method for isolating the Fe XVIII emission in the AIA/SDO 94{AA} channel. The resulting differential emission measure distributions confirm our previous analysis showing that the temperature distribution in an active region core is often strongly peaked near 4MK. We characterize the properties of the emission distribution as a function of the total unsigned magnetic flux. We find that the amount of high-temperature emission in the active region core is correlated with the total unsigned magnetic flux, while the emission at lower temperatures, in contrast, is inversely related. These results provide compelling evidence that high-temperature active region emission is often close to equilibrium, although weaker active regions may be dominated by evolving million degree loops in the core.2012ApJ...759..141Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/759/141CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/555/A123 : 3D-MHD model of a solar active region corona (Bourdin+, 2013)J/A+A/552/A114 : Sun chromospheric CaII-HK emission (Shapiro+, 2013)J/ApJ/752/126 : Modeling the magnetic field in the corona (Yamamoto+, 2012)J/ApJS/181/351 : Solar flux model in 30-1300nm wavelength range (Killen+, 2009)J/A+A/432/1063 : Analysis of inner solar corona in EUV (Lanzafame+, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/759/141https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/759/141http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/759/141https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/759/141https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/759/141http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/759/141GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/759/141/table2aDifferential Emission Measure Model from EIS (EUV Imaging Spectrometer) instrumentO/D(Int)[0.6/2.9] Ratio of OInt to DIntspect.line.intensity;arith.ratiofloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintReg[1/16] Active region (G1)obs.fieldintLineLine identifiermeta.id;spect.linecharlambda[180/285] Line wavelength ({AA})0.1nmem.wl;spect.linefloatOInt[7.9/12734] Observed intensity (1)mW.m**-2.sr**-1spect.line.intensitydoublee_OInt[1.7/2802] Error in OInt (1)mW.m**-2.sr**-1stat.errorfloatDInt[6.6/19162] Differential emission measure intensity (1)mW.m**-2.sr**-1spect.line.intensity;arith.diffdoubleJ/ApJ/759/141/table2bDifferential Emission Measure Model from AIA (Atmospheric Imaging Assembly) instrumentReg[1/16] Active region (G1)obs.fieldintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[94] Wavelength identifier (in {AA})0.1nmmeta.id;em.wlintOInt[2.1/102] Observed intensity (1)spect.line.intensitydoublee_OInt[0.4/21] Error in OInt (1)stat.errorfloatDInt[2.8/116] Differential emission measure intensity (1)spect.line.intensitydoubleO/D(Int)[0.6/1.3] Ratio of OInt to DIntspect.line.intensity;arith.ratiofloat