The brightest explosions in the Universe: gamma-ray bursts and soft-gamma repeaters

Institutskolloquium

  • Datum: 19.02.2021
  • Uhrzeit: 10:30 - 12:00
  • Vortragender: Dr. Dmitry Svinkin
  • Dr. Dmitry Svinkin, Research Scientist, Ioffe Institute Laboratory for Experimental Astrophysics Dr. Svinkin is the deputy principal investigator of Russian-US Konus-Wind experiment and the main researcher of the Interplanetary network (a collaboration of space-based instruments for gamma-ray burst observations). His main areas of research include multiwavelength observations of gamma-ray bursts (GRBs), soft gamma-repeaters (SGRs), and solar flares. Recently he has been participating in electromagnetic counterpart searches of gravitational waves in collaboration with LIGO/Virgo gravitational wave observatory teams and searches for gamma-ray counterparts of fast optical transients in collaboration with the Zwicky Transient Facility (Palomar Observatory) and the MASTER robotic telescope network (MSU). His main results include localization of short gamma-ray burst GRB 170817A accompanied by gravitational waves (ApJL 848, 12, 2017; arXiv: 1710.05833) and analyses and searches for SGR extragalactic giant flares (Nature 589, 211, 2021; arXiv:2101.05144). Dr. Svinkin is also involved in development of GRB dedicated space-based instruments at Ioffe Institute.
  • Ort: Zoom Meeting Room 2
  • Gastgeber: Dmitry Moseev
  • Kontakt: dmitry.moseev@ipp.mpg.de
The brightest explosions in the Universe: gamma-ray bursts and soft-gamma repeaters

Gamma-ray bursts are the brightest explosions in the Universe, with luminosities up to a few 1054 erg/s, which are believed to originate from at least two distinct catastrophic processes in galaxies at cosmological distances. The core collapse of a massive star may produce long GRBs, which are typically longer than ~2 s, while the merger of a binary compact objects (double neutron star or a neutron star and a black hole) is a source of short GRBs (shorter than ~2 s) and gravitational waves. However, the observed populations of short GRBs may contain a number of less energetic, but also spectacular events from nearby galaxies.


Magnetars are a special rare class of neutron stars with strong magnetic fields (B ~ 1014-1015 G). Some magnetars (or Soft-Gamma Repeaters, SGRs) exhibit bursting emission in hard X-rays/soft gamma-rays. During the active stage, which may last from several days to years, SGRs emit randomly occurring short (from milliseconds to seconds long) hard X-ray bursts with peak luminosities of ~1038 - 1042 erg/s. Much more rarely, perhaps only once during the SGR stage, a magnetar may emit a giant flare with the sudden release of an enormous amount of energy in the form of gamma-rays ~ 1044 – 1046 erg, which can be detected in nearby galaxies up to a tens of millions light years. Only a dozen burst-emitting magnetars in our Galaxy and Large Magellanic Cloud are known so far and only three of them produced a giant flare during the active stage.


The talk will overview the current progress in understanding of nature of gamma-ray bursts, soft gamma-repeaters, and their connection with other transient astrophysical phenomena - supernovae and fast radio bursts.

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