Chromatic Afterglow of GRB 200829A
Minaev, P. Yu.; Pozanenko, A. S.; Volnova, A. A.; Rumyantsev, V. V.; Antonyuk, K. A.; Reva, I. V.; Moskvitin, A. S.; Inasaridze, R. Ya.; Klunko, E. V.; Molotov, I. E.; Burkhonov, O. A.; Egamberdiev, Sh. A.; Pankov, N. S.; Belkin, S. O.; Serebryanskii, A. V.; Krugov, M. A.; Naroenkov, S. A.; Novichonok, A. O.; Zhornichenko, A. A.
Russia, Kazakhstan, Uzbekistan, Georgia
Abstract
We present the results of our analysis of multiwavelength observations for the long gamma-ray burst GRB 200829A. The burst redshift $z≈ 1.29± 0.04$ has been determined photometrically at the afterglow phase. In gamma rays the event is one of the brightest (in isotropic equivalent), $E_{\textrm{iso}}\gtrsim 10^{54}$ 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.