# Late afterglow emission statistics: a clear link between GW170817 and bright short GRBs

## TL;DR

This study compares the afterglow emissions of GW170817 and other short GRBs, revealing a continuous sequence and supporting the link between neutron star mergers and bright short GRBs, with implications for future detections.

## Contribution

It demonstrates a clear connection between GW170817-like mergers and bright short GRBs through afterglow emission analysis, highlighting observational challenges.

## Key findings

- GW170817's afterglow aligns with bright short GRBs in decay phase
- On-axis viewing makes GW170817's afterglow among the brightest
- Most neutron star mergers' afterglows are harder to detect due to distance and viewing angles

## Abstract

GW170817, the first neutron star merger event detected by advanced LIGO/Virgo detectors, was associated with an underluminous short duration GRB 170817A. In this work we compare the forward shock afterglow emission of GW170817/GRB 170817A to other luminous short GRBs (sGRBs) with both a known redshift and an afterglow emission lasting at least one day after the burst. In the rapid decay phase, the afterglow emission of the bright sGRBs and GW170817/GRB 170817A form a natural and continuous sequence, though separated by an observation time gap. If viewed on-axis, the forward shock afterglow emission of GW170817/GRB 170817A would be among the brightest ones detected so far. This provides a strong evidence for the GW170817-like merger origin of bright sGRBs, and suggests that the detection of the forward shock afterglow emission of most neutron star merger events are more challenging than the case of GW170817 since usually the mergers will be more distant and the viewing angles are plausibly higher.