GRB follow-up and science with THESEUS/IRT

TL;DR

The THESEUS/IRT mission aims to enhance gamma-ray burst studies by providing unprecedented sensitivity in optical and near-infrared observations, enabling detection of high-redshift bursts and improving follow-up capabilities beyond ground-based limitations.

Contribution

This work explores the advantages of a satellite-mounted optical and near-infrared telescope for GRB follow-up, highlighting its potential to detect more high-redshift and prompt-phase GRBs than ground-based telescopes.

Findings

Over half of detected sources are unobservable from ground-based telescopes.

Only about 50% of sources are visible within one hour of detection.

The mission could increase the number of studied GRBs from gamma-ray to near-infrared to over 10 per year.

Abstract

The aim of the space mission concept \theseus~is to continue to collect and study the GRB events like \swift. It will allow us to study the early Universe. Moreover, it will offer us to study with unprecedented sensitivity GRB emission and to measure the redshift for the bursts with $z>5$. In this work, we investigate the advantages of a optical and near-infrared telescope mounted on the same satellite that is triggered by the GRB like \theseus/IRT. Afterwards, we investigate the possible future developments in the GRB science, first for the prompt phase and the for afterglow phase. We find that more than half of the sources detected by \theseus, and will never be visible from a a ground-based telescope. Moreover, only $\sim50\%$ of all observable sources are visible within one hour, i.e. $<30\%$ of all \theseus~transient sources. A higher number of observable sources can only be achieved with a network of telescopes. \theseus~will permit to detect the NIR prompt phase of the longest GRBs, increasing the number of events studied from gamma-rays to the near-infrared from a handful of events studied up to now to $\gtrsim10$ GRBs per year.