TY - JOUR
T1 - Machine-learning enhanced photometric analysis of the extremely bright GRB 210822A
AU - Angulo-Valdez, Camila
AU - Becerra, Rosa L.
AU - Pereyra, Margarita
AU - Garcia-Cifuentes, Keneth
AU - Vargas, Felipe
AU - Watson, Alan M.
AU - De Colle, Fabio
AU - Fraija, Nissim
AU - Butler, Nathaniel R.
AU - Dainotti, Maria G.
AU - Dichiara, Simone
AU - Lee, William H.
AU - Troja, Eleonora
AU - Bloom, Joshua S.
AU - González, J. Jesús
AU - Kutyrev, Alexander S.
AU - Prochaska, J. Xavier
AU - Ramirez-Ruiz, Enrico
AU - Richer, Michael G.
N1 - Publisher Copyright:
© 2023 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
PY - 2024/1/1
Y1 - 2024/1/1
N2 - We present analytical and numerical models of the bright long GRB 210822A at z = 1.736. The intrinsic extreme brightness exhibited in the optical, which is very similar to other bright GRBs (e.g. GRBs 080319B, 130427A, 160625A 190114C, and 221009A), makes GRB 210822A an ideal case for studying the evolution of this particular kind of GRB. We use optical data from the RATIR instrument starting at T + 315.9 s, with publicly available optical data from other ground-based observatories, as well as Swift/UVOT, and X-ray data from the Swift/XRT instrument. The temporal profiles and spectral properties during the late stages align consistently with the conventional forward shock model, complemented by a reverse shock element that dominates optical emissions during the initial phases (T < 300 s). Furthermore, we observe a break at T = 80 000 s that we interpreted as evidence of a jet break, which constrains the opening angle to be about θj = (3-5) degrees. Finally, we apply a machine-learning technique to model the multiwavelength light curve of GRB 210822A using the afterglowpy library. We estimate the angle of sight θobs = (6.4 ± 0.1) × 10-1 degrees, the energy E0 = (7.9 ± 1.6) × 1053 erg, the electron index p = 2.54 ± 0.10, the thermal energy fraction in electrons e = (4.63 ± 0.91) × 10-5 and in the magnetic field B = (8.66 ± 1.01) × 10-6, the efficiency χ = 0.89 ± 0.01, and the density of the surrounding medium n0 = 0.85 ± 0.01 cm-3.
AB - We present analytical and numerical models of the bright long GRB 210822A at z = 1.736. The intrinsic extreme brightness exhibited in the optical, which is very similar to other bright GRBs (e.g. GRBs 080319B, 130427A, 160625A 190114C, and 221009A), makes GRB 210822A an ideal case for studying the evolution of this particular kind of GRB. We use optical data from the RATIR instrument starting at T + 315.9 s, with publicly available optical data from other ground-based observatories, as well as Swift/UVOT, and X-ray data from the Swift/XRT instrument. The temporal profiles and spectral properties during the late stages align consistently with the conventional forward shock model, complemented by a reverse shock element that dominates optical emissions during the initial phases (T < 300 s). Furthermore, we observe a break at T = 80 000 s that we interpreted as evidence of a jet break, which constrains the opening angle to be about θj = (3-5) degrees. Finally, we apply a machine-learning technique to model the multiwavelength light curve of GRB 210822A using the afterglowpy library. We estimate the angle of sight θobs = (6.4 ± 0.1) × 10-1 degrees, the energy E0 = (7.9 ± 1.6) × 1053 erg, the electron index p = 2.54 ± 0.10, the thermal energy fraction in electrons e = (4.63 ± 0.91) × 10-5 and in the magnetic field B = (8.66 ± 1.01) × 10-6, the efficiency χ = 0.89 ± 0.01, and the density of the surrounding medium n0 = 0.85 ± 0.01 cm-3.
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U2 - 10.1093/mnras/stad3624
DO - 10.1093/mnras/stad3624
M3 - Article
AN - SCOPUS:85180535300
SN - 0035-8711
VL - 527
SP - 8140
EP - 8150
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -