TY CONF TI Investigation of magnetic free energy dynamics in the M1.2-class complex solar flare of March 15, 2015 using the 135-second HMI vector magnetograms KW Sun: solar flares KW magnetic fields; electric currents; eruption; hard X-ray emission JO Modern astronomy: from the Early Universe to exoplanets and black holes AU Sharykin, I.. AU Zimovets, I.. AU Myshyakov, I.. AU Anfinogentov, S.. PY 2024 PB Special Astrophysical Observatory of the Russian Academy of Sciences