Cosmic Gamma-ray Bursts (GRBs) and Soft Gamma-ray Repeaters (SGRs) are the brightest sources of the high-energy electromagnetic radiation. For many years, GRB and SGR studies are among the major fundamental research areas at Ioffe Institute. The physical processes behind the huge luminosity of the cosmic gamma-ray sources are of fundamental interest since they provide an opportunity to study physical phenomena in vicinities of stellar-mass black holes and on neutron stars with magnetic fields probably larger than the critical value for vacuum polarization, the conditions inaccessible to terrestrial laboratories. The high luminosities of GRBs make them detectable out to the edge of the visible universe thus enabling to study the nature of the first stars in the Universe and to probe the matter properties along the whole line of sight to the sources. In this paper, we give a short review of the history of the GRB and SGR studies and describe the latest results from multi-wavelength observations of the phenomena. In this context, we review the key results from several generations of the KONUS GRB experiments by Ioffe Institute and complemented by theoretical modeling of the extreme astrophysical processes. Finally, we consider the prospects for the GRB and SGR studies including the future experiments by Ioffe Institute.
Keywords: cosmic gamma-ray bursts, soft gamma-repeaters, burst light curves, burst energy spectra DOI:10.3367/UFNe.2018.11.038488 Citation: Aptekar R L, Bykov A M, Golenetskii S V, Frederiks D D, Svinkin D S, Ulanov M V, Tsvetkova A E, Kozlova A V, Lysenko A L "Cosmic gamma-ray bursts and soft gamma-repeaters – observations and modeling of the extreme astrophysical phenomena" Phys. Usp., accepted
Received: 23rd, August 2018, revised: 23rd, November 2018, accepted: 29th, November 2018