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arXiv · 2308.02090

Chromatic Afterglow of GRB 200829A

N. S. Pankov·A. S. Pozanenko·P. Yu. Minaev·S. O. Belkin·A. A. Volnova·I. V. Reva·A. V. Serebryanskiy·M. A. Krugov·S. A. Naroenkov·A. O. Novichonok·A. A. Zhornichenko·V. V. Rumyantsev·K. A. Antonyuk·Sh. A. Egamberdiev·O. A. Burkhonov·E. V. Klunko·A. S. Moskvitin·I. E. Molotov·R. Ya. Inasaridze
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Abstract

We present the results of our analysis of multiwavelength observations for the long gamma-ray burst GRB 200829A. The burst redshift $z \approx 1.29 \pm 0.04$ has been determined photometrically at the afterglow phase. In gamma rays the event is one of the brightest (in isotropic equivalent), $E_{iso} \gtrsim 10^{54}$ erg. The multicolor light curve of the GRB 200829A afterglow is characterized by chromatic behavior and the presence of a plateau gradually transitioning into a power-law decay that can also be interpreted as a quasi-synchronous inhomogeneity (flare). We assume that the presence of a chromatic inhomogeneity in the early afterglow is consistent with the model of a structured jet.

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N. S. Pankov, A. S. Pozanenko, P. Yu. Minaev, S. O. Belkin, A. A. Volnova, I. V. Reva, A. V. Serebryanskiy, M. A. Krugov, S. A. Naroenkov, A. O. Novichonok, A. A. Zhornichenko, V. V. Rumyantsev, K. A. Antonyuk, Sh. A. Egamberdiev, O. A. Burkhonov, E. V. Klunko, A. S. Moskvitin, I. E. Molotov, R. Ya. Inasaridze. 2023-08-04. Chromatic Afterglow of GRB 200829A. https://doi.org/10.1134/s1063773723030052

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