# A comparison between short GRB afterglows and AT2017gfo: shedding light on kilonovae properties

## TL;DR

This study compares the optical and near-infrared light curves of 39 short gamma-ray bursts to the kilonova AT2017gfo, revealing insights into the luminosity range of kilonova components and supporting previous detections.

## Contribution

First comprehensive analysis of AT2017gfo-like kilonova signatures in short GRB light curves, distinguishing blue and red component luminosities and refining kilonova detection criteria.

## Key findings

- Red kilonova component luminosity similar to AT2017gfo.
- Blue kilonova component can be over 10 times brighter.
- Exclusion of AT2017gfo-like kilonova in GRBs 050509B and 061201.

## Abstract

Multi-messenger astronomy received a great boost following the discovery of kilonova AT2017gfo, the optical counterpart of the gravitational wave source GW170817 associated with the short gamma-ray burst GRB 170817A. AT2017gfo was the first kilonova that could be extensively monitored in time both photometrically and spectroscopically. Previously, only few candidates have been observed against the glare of short GRB afterglows. In this work, we aim to search the fingerprints of AT2017gfo-like kilonova emissions in the optical/NIR light curves of 39 short GRBs with known redshift. For the first time, our results allow us to study separately the range of luminosity of the blue and red components of AT2017gfo-like kilonovae in short GRBs. In particular, the red component is similar in luminosity to AT2017gfo, while the blue kilonova can be more than 10 times brighter. Finally, we find further evidence to support all the claimed kilonova detections and we exclude an AT2017gfo-like kilonova in GRBs 050509B and 061201.