Observational Limits on Inverse Compton Processes in GRBs

TL;DR

This paper examines the inverse Compton process in gamma-ray bursts and finds that it likely overproduces high-energy emission, conflicting with observed energy constraints, thus challenging its role in prompt gamma-ray production.

Contribution

The study provides a general analysis showing that inverse Compton scattering cannot be the dominant mechanism for prompt gamma-ray emission in GRBs without violating energy limits.

Findings

Inverse Compton overproduces high-energy emission in GRBs.

Energy crisis challenges the viability of IC as the main prompt emission mechanism.

Analysis is model-independent and based on observational upper limits.

Abstract

Inverse Compton (IC) scattering is one of two viable mechanisms that can produce the prompt gamma-ray emission in Gamma-Ray Bursts. IC requires low energy seed photons and a population of relativistic electrons that upscatter them. The same electrons can upscatter the gamma-ray photons to even higher energies in the TeV range. Using the current upper limits on the prompt optical emission we show here that under general conservative assumption the IC mechanism suffers from an "energy crisis". Namely, IC will over-produce a very high energy component that would carry much more energy than the observed prompt gamma-rays. Our analysis is general and it makes no assumptions on the specific mechanism that produces the relativistic electrons population.