Revealing x-ray and gamma ray temporal and spectral similarities in the GRB 190829A afterglow
GIUNTI, L.
Institut de Recherches sur les lois Fondamentales de l'Univers [IRFU]
AstroParticule et Cosmologie [APC (UMR_7164)]
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Institut de Recherches sur les lois Fondamentales de l'Univers [IRFU]
AstroParticule et Cosmologie [APC (UMR_7164)]
Language
en
Article de revue
This item was published in
Science. 2021, vol. 372, n° 6546, p. 1081-1085
American Association for the Advancement of Science (AAAS)
English Abstract
<p>Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy ...Read more >
<p>Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera–electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.</p>Read less <
English Keywords
gamma ray: burst
gamma ray: VHE
energy: high
X-ray: energy spectrum
absorption
spectral
collapse
redshift
trigger
photon
HESS
Origin
Hal imported