Consequent Flares X5.4 and X1.3 on March 7, 2012 and Associated Coronal Mass Ejections.

In this paper, we study the pair of flares X5.4 and X1.3 that occurred on March 7, 2012, which happened in the same active region with a delay of about 1 hour. They were accompanied by long-term (>18 h) γ-radiation with energy of more than 100 MeV. Each of them was accompanied by a fast coronal mass ejection at more than 1800 km/s. The second X1.3 flare is distinguished by small changes in the soft X-ray intensity, temperature, and radiating plasma emission, despite the fact that the hard X-ray intensity at the maximum was comparable to the first X5.4 flare. An analysis of the observations shows: (1) the larger X-ray class of the first X5.4 flare is associated with chromospheric evaporation into low coronal loops, (2) the smaller class of the second X1.3 flare can be explained by chromospheric evaporation only into high coronal loops left after the first flare, (3) in both flares, the acceleration of the coronal mass ejection occurred in the impulsive and prolonged phases both before and after the maxima of hard X-ray bursts, (4) the higher velocity of the coronal mass ejection in X5.4 by 20 R_s is related to the magnitude and duration of the acceleration, and (5) in both flares, relativistic electrons and protons accelerated stochastically during the posteruptive phase. [ABSTRACT FROM AUTHOR]