# Analysis and modelling of the multi-wavelength observations of the luminous GRB 190114C

## TL;DR

This paper analyzes multi-wavelength observations of GRB 190114C, revealing that different emission phases are consistent with synchrotron and inverse Compton models, and suggests magnetic fields influence the outflow's properties.

## Contribution

It provides a comprehensive modeling of the GRB's emission across wavelengths, combining synchrotron and inverse Compton processes, and discusses the role of magnetic fields in the outflow.

## Key findings

- High-energy photons produced during the deceleration phase of the outflow.
- Short-lived peaks explained by synchrotron self-Compton reverse-shock model.
- Long-lived emission consistent with a stratified medium evolving to a uniform medium.

## Abstract

Very-high-energy (VHE; $\geq 10$ GeV) photons are expected from the nearest and brightest Gamma-ray bursts (GRBs). VHE photons, at energies higher than 300 GeV, were recently reported by the MAGIC collaboration for this burst. Immediately, GRB 190114C was followed up by a massive observational campaign covering a large fraction of the electromagnetic spectrum. In this paper, we obtain the LAT light curve of GRB 190114C and show that it exhibits similar features to other bright LAT-detected bursts; the first high-energy photon ($\geq$ 100 MeV) is delayed with the onset of the prompt phase and the flux light curve exhibits a long-lived emission (lasting much longer than the prompt phase) and a short-lasting bright peak (located at the beginning of long-lived emission). Analyzing the multi-wavelength observations, we show that the short-lasting LAT and GBM bright peaks are consistent with the synchrotron self-Compton reverse-shock model and the long-lived observations with the standard synchrotron forward-shock model that evolves from a stratified stellar-wind like medium to a uniform ISM-like medium. Given the best-fit values, a bright optical flash produced by synchrotron reverse-shock emission is expected. From our analysis we infer that the high-energy photons are produced in the deceleration phase of the outflow and some additional processes to synchrotron in the forward shocks should be considered to properly describe the LAT photons with energies beyond the synchrotron limit. Moreover, we claim that an outflow endowed with magnetic fields could describe the polarization and properties exhibited in the light curve of GRB 190114C.