J/ApJ/757/94ivo://CDS.VizieR/J/ApJ/757/94doi:10.26093/cds/vizier.17570094CDSAschwanden M.J.2014-07-16T22:06:41Z2014-07-02T10:48:14ZCDS support team

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

cds-question@unistra.frthe-sunstellar-flaresWe explore the spatio-temporal evolution of solar flares by fitting a radial expansion model r(t) that consists of an exponentially growing acceleration phase, followed by a deceleration phase that is parameterized by the generalized diffusion function r(t){prop.to}{kappa}(t-t_1_)^{beta}/2^, which includes the logistic growth limit ({beta}=0), sub-diffusion ({beta}=0-1), classical diffusion ({beta}=1), super-diffusion ({beta}=1-2), and the linear expansion limit ({beta}=2). We analyze all M- and X-class flares observed with Geostationary Operational Environmental Satellite and Atmospheric Imaging Assembly/Solar Dynamics Observatory (SDO) during the first two years of the SDO mission, amounting to 155 events. We find that most flares operate in the sub-diffusive regime ({beta}=0.53+/-0.27), which we interpret in terms of anisotropic chain reactions of intermittent magnetic reconnection episodes in a low plasma-{beta} corona. We find a mean propagation speed of v=15+/-12km/s, with maximum speeds of v_max_=80+/-85km/s per flare, which is substantially slower than the sonic speeds expected for thermal diffusion of flare plasmas. The diffusive characteristics established here (for the first time for solar flares) is consistent with the fractal-diffusive self-organized criticality model, which predicted diffusive transport merely based on cellular automaton simulations.2012ApJ...757...94Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/757/94CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/747/L41 : Solar flares probabilities (Bloomfield+, 2012)J/A+A/304/563 : Cool X-ray flares of Sun with GOES (Phillips+, 1995)http://sdo.gsfc.nasa.gov/ : Solar Dynamics Observatory home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/757/94https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/757/94http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/757/94https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/757/94https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/757/94http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/757/94GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/757/94/table1Catalog of analyzed M- and X-class flare events and best-fit model parameters: length scale L(Mm), diffusion coefficient K (km.s^-{beta}/2^), diffusion index {beta}, and goodness of fit q_fit_Seq[1/155] Running sequence numbermeta.id;meta.mainintprimaryDateUT observation datetime.epoch;obsnullableTstStart timetime.epochnullableTpkPeak timetime.epochnullableTendEnd timetime.epochnullableDur[300/14760] Durationstime.durationintCl[MX0-9.] Geostationary Operational Environmental Satellite (GOES) class of flaresrc.classcharAOR[11079/11445] NOAA AR numbermeta.id;obsintPosHeliographic positionmeta.notecharL[5/51] Length scaleMmsrc.morph.scLengthintk[18/139] Diffusion coefficient {kappa} (1)stat.fit.paraminte_k[0/25] k uncertaintystat.errorintbeta[0.04/1.4] Diffusion index {beta} (1)stat.fit.paramfloate_beta[0/0.5] beta uncertaintystat.errorfloatFit[0.8/4.2] Goodness of fit (q_fit_)%stat.fit.goodness;arith.ratiofloat