Hot coronal loops associated with umbral brightenings

Abstract

We analyzed AIA/SDO high-cadence images in all bands, HMI/SDO data, soft X-ray images from SXI/GOES-15, and Halpha images from the GONG network. We detected umbral brightenings that were visible in all AIA bands as well as in Halpha. Moreover, we identified hot coronal loops that connected the brightenings with nearby regions of opposite magnetic polarity. These loops were initially visible in the 94 A band, subsequently in the 335 A band, and in one case in the 211 A band. A differential emission measure analysis revealed plasma with an average temperature of about 6.5x10^6 K. This behavior suggests cooling of impulsively heated loops.

A&A, 2013, in press

References in corpus (3)

• Spectral Line Selection for HMI: A Comparison of Fe I 6173 and Ni I 6768
• The temporal evolution of coronal loops observed by GOES-SXI
• Static and Impulsive Models of Solar Active Regions

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• Evidence for two-loop interaction from IRIS and SDO observations of penumbral brightenings
• Heating of quiescent coronal loops caused by nearby eruptions observed with the Solar Dynamics Observatory and the Solar Upper Transition Region Imager