TY - JOUR

T1 - Low frequency view of GRB 190114C reveals time varying shock micro-physics

AU - Misra, K.

AU - Resmi, L.

AU - Kann, D. A.

AU - Marongiu, M.

AU - Moin, A.

AU - Klose, S.

AU - Bernardi, G.

AU - de Ugarte Postigo, A.

AU - Jaiswal, V. K.

AU - Schulze, S.

AU - Perley, D. A.

AU - Ghosh, A.

AU - Dimple, Dimple

AU - Kumar, H.

AU - Gupta, R.

AU - Michalowski, M. J.

AU - Martin, S.

AU - Cockeram, A.

AU - Cherukuri, S.

AU - Bhalerao, V.

AU - Anderson, G. E.

AU - Pandey, S. B.

AU - Anupama, G. C.

AU - Thone, C. C.

AU - Barway, S.

AU - Wieringa, M. H.

AU - Fynbo, J. P. U.

AU - Habeeb, N.

PY - 2021/7/4

Y1 - 2021/7/4

N2 - We present radio and optical afterglow observations of the TeV-bright long gamma-ray burst 1901140 at a redshift of z = 0.425, which was detected by the Major Atmospheric Gamma Imaging Cherenkov telescope. Our observations with Atacama Large Millimeter/submillitmeter Array, Australia Telescope Compact Array, and upgraded Giant Metre-wave Radio Telescope were obtained by our low frequency observing campaign and range from similar to 1 to similar to 140 d after the burst and the optical observations were done with three optical telescopes spanning up to similar to 25 d after the burst. Long-term radio/mm observations reveal the complex nature of the afterglow, which does not follow the spectral and temporal closure relations expected from the standard afterglow model. We find that the microphysical parameters of the external forward shock, representing the share of shock-created energy in the non-thermal electron population and magnetic field, are evolving with time. The inferred kinetic energy in the blast-wave depends strongly on the assumed ambient medium density profile, with a constant density medium demanding almost an order of magnitude higher energy than in the prompt emission, while a stellar wind-driven medium requires approximately the same amount energy as in prompt emission.

AB - We present radio and optical afterglow observations of the TeV-bright long gamma-ray burst 1901140 at a redshift of z = 0.425, which was detected by the Major Atmospheric Gamma Imaging Cherenkov telescope. Our observations with Atacama Large Millimeter/submillitmeter Array, Australia Telescope Compact Array, and upgraded Giant Metre-wave Radio Telescope were obtained by our low frequency observing campaign and range from similar to 1 to similar to 140 d after the burst and the optical observations were done with three optical telescopes spanning up to similar to 25 d after the burst. Long-term radio/mm observations reveal the complex nature of the afterglow, which does not follow the spectral and temporal closure relations expected from the standard afterglow model. We find that the microphysical parameters of the external forward shock, representing the share of shock-created energy in the non-thermal electron population and magnetic field, are evolving with time. The inferred kinetic energy in the blast-wave depends strongly on the assumed ambient medium density profile, with a constant density medium demanding almost an order of magnitude higher energy than in the prompt emission, while a stellar wind-driven medium requires approximately the same amount energy as in prompt emission.

KW - gamma-ray burst

KW - general-gamma-ray burst

KW - individual-GRB 190114C

KW - radio observations

KW - GAMMA-RAY-BURST

KW - AFTERGLOW LIGHT CURVES

KW - HIGH-ENERGY EMISSION

KW - REVERSE SHOCK

KW - SWIFT-ERA

KW - PRE-SWIFT

KW - OPTICAL AFTERGLOW

KW - RADIO AFTERGLOW

KW - SCINTILLATION

KW - SYNCHROTRON

U2 - 10.1093/mnras/stab1050

DO - 10.1093/mnras/stab1050

M3 - Journal article

VL - 504

SP - 5685

EP - 5701

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

SN - 0035-8711

IS - 4

ER -