naa a22 4500 510790607 CHVBK 20180411083318.0 cr unu---uuuuu 180411e20131101xx s 000 0 eng 10.1134/S1063773713110042 doi (NATIONALLICENCE)springer-10.1134/S1063773713110042 Long-duration plasma heating in solar microflares of X-ray class A1.0 and lower [Elektronische Daten] [A. Kirichenko, S. Bogachev] Three solar microflares of X-ray class ∼A1.0 and lower observed at solar activity minimum in 2009 have been studied: the April 19, 2009 flare (A0.38), the June 24, 2009 flare (A0.47), and the July 18, 2009 flare (A2.2). A distinguishing feature of these events from other microflares of low X-ray classes was the maintenance of a high plasma temperature (T ≳ 4 MK) at the decay phase well after the flare peak. The lifetimes of the high-temperature emission source in the corona in all three cases exceed considerably its conductive and radiative cooling times, while the thermal energy released at the decay phase of the flare exceeds the energy liberated during its impulsive phase by an order of magnitude. It is hypothesized that a high plasma temperature in microflares of low X-ray classes can be maintained for a long time through magnetic reconnection associated with mass ejections from the flare region. The lifetime of the hot plasma in the corona in this case can exceed appreciably the plasma cooling time. The study has shown that the eruption of material actually occurred in all three investigated microflares. Pleiades Publishing, Inc., 2013 Sun nationallicence microflares nationallicence high-temperature plasma nationallicence Kirichenko A. Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, 119991, Moscow, Russia aut Bogachev S. Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, 119991, Moscow, Russia aut Astronomy Letters Springer US; http://www.springer-ny.com 39/11(2013-11-01), 797-807 1063-7737 39:11<797 2013 39 11443 https://doi.org/10.1134/S1063773713110042 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1063773713110042 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kirichenko A. Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, 119991, Moscow, Russia aut NATIONALLICENCE 700 1- Bogachev S. Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, 119991, Moscow, Russia aut NATIONALLICENCE 773 0- Astronomy Letters Springer US; http://www.springer-ny.com 39/11(2013-11-01), 797-807 1063-7737 39:11<797 2013 39 11443 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer