Induced Gravitational Collapse

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The term Induced Gravitational Collapse describes an alternative model for the connection between long gamma-ray flashes and supernovae of type Ib / c .

Gamma-ray bursts are explosions in which energies in the 10 49 -10 54 erg range are released mainly as gamma radiation . According to the duration of the bursts, gamma-ray bursts are divided into long ones with a duration of more than two seconds and short gamma-ray bursts. In some of the long eruptions, supernovae of type Ib / c were discovered at the location of the gamma-ray flash . This is mostly explained using the collapsar model, according to which the eruption of a rapidly rotating massive blue giant star leads to the gamma-ray burst . The star's core collapses into a neutron star, and the star's incident matter is reflected off the protoneutron star's crust. Due to the rapid rotation, the matter reflected by the nucleus emerges at the rotation poles and in connection with a magnetic field an ultra-relativistic jet is created , which emits most of the energy in a very small solid angle of the order of one square degree. If the direction of the jet is aligned with the earth, then this event is perceived as a gamma-ray flash.

This standard model of long gamma-ray bursts has been criticized in part because the blue giants lose several solar masses to a stellar wind before their supernova explosion and an interaction of a relativistic jet that does not point to Earth with circumstellar matter has never been observed. An alternative model is the Induced Gravitational Collapse. Then gamma-ray bursts are created in a close binary star system consisting of a blue giant and a neutron star. The blue giant explodes in a supernova and part of the expanding matter is accreted by the compact star . In doing so, the mass of the neutron star exceeds the stability criterion, the Tolman-Oppenheimer-Volkoff limit , and collapses into a black hole . This releases the energy observed as gamma-ray bursts, composed of the potential energy and the collapse of the neutron star's magnetic field. The model of the Induced Gravitational Collapse easily explains the precursors observed in some gamma-ray bursts, according to which a weak outbreak in the range of gamma and X-rays could be detected a few seconds to minutes before the main outbreak at the location of a gamma ray burst .

literature

  • Jorge A. Rueda, Remo Ruffini: On the Induced Gravitational Collapse of a Neutron Star to a Black Hole by a Type Ib / c Supernova . In: Astrophysics. Solar and Stellar Astrophysics . 2012, arxiv : 1206.1684v3 .
  • Ana Virginia Penacchioni et al. a .: GRB 110709B in the Induced Gravitational Collapse paradigm . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1301.6014v1 .
  • Giovanni Battista Pisani et al. a .: On a novel distance indicator for Gamma-Ray Bursts associated with Supernovae . In: Astrophysics. Solar and Stellar Astrophysics . 2013, arxiv : 1309.0454v1 .