Lag-luminosity relation in gamma-ray burst X-ray flares

TL;DR

This paper demonstrates a fundamental lag-luminosity relation in GRB X-ray flares, similar to prompt pulses, indicating a common underlying mechanism across different emission phases.

Contribution

It establishes a new lag-luminosity relation for X-ray flares, extending the known correlation over five decades in time and energy, linking flares to prompt emission mechanisms.

Findings

Lag-luminosity relation: L_p,iso ∝ t_lag^{-0.95±0.23}

Relation extends over 5 decades in time and energy

Supports a common origin for X-ray flares and prompt gamma-ray pulses

Abstract

In strict analogy to prompt pulses, X-ray flares observed by Swift-XRT in long Gamma-Ray Bursts define a lag-luminosity relation: L_p,iso \propto t_lag^{-0.95+/-0.23}. The lag-luminosity is proven to be a fundamental law extending 5 decades in time and 5 in energy. This is direct evidence that GRB X-ray flares and prompt gamma-ray pulses are produced by the same mechanism.