# Sensitivity to point-like sources of the ALTO atmospheric particle detector array, designed for $\rm 200\,GeV$--$\rm 50\,TeV$ $γ$-ray astronomy

**Authors:** M. Punch, M. Senniappan, Y. Becherini, G. Kukec Mezek, S. Thoudam, T. Bylund, J. -P. Ernenwein  
**arXiv:** [2303.15248](https://arxiv.org/abs/2303.15248)  
**Date:** 2023-03-27  
**Summary page:** https://www.summarizepaper.com/en/arxiv-id/2303.15248v1/

## Key points

- The study is about the sensitivity to point-like sources of the ALTO atmospheric particle detector array designed for $\gamma$-ray astronomy in the energy range of 200 GeV to 50 TeV.
- Monte Carlo simulations are used to estimate the impact of heavier nuclei in cosmic rays on $\gamma$-ray detection performance and develop a method for calculating sensitivity to point-like sources.
- Observation times required to achieve firm detections on a list of known point-like sources are determined.
- Heavier nuclei in cosmic rays can significantly affect $\gamma$-ray detection performance, particularly at lower energies.
- The method for calculating sensitivity to point-like sources is effective and reliable, as demonstrated by applying it to known sources and comparing results with previous studies.
- Estimates for observation times required to achieve firm detections on these sources using ALTO are provided.
- This study provides valuable insights into improving $\gamma$-ray detection performance in atmospheric shower arrays by accounting for heavier nuclei in cosmic rays and developing an effective method for calculating sensitivity to point-like sources.
- These findings have important implications for future research in high-energy astrophysics and could lead to significant advancements in our understanding of the universe's most energetic phenomena.

## Summary

This paper presents a study on the sensitivity to point-like sources of the ALTO atmospheric particle detector array, which is designed for $\gamma$-ray astronomy in the energy range of 200 GeV to 50 TeV. The authors use dedicated Monte Carlo simulations to estimate the impact of heavier nuclei in the cosmic-ray background on $\gamma$-ray detection performance and develop a method for calculating sensitivity to point-like sources. They determine the required observation times necessary to achieve a firm detection on a list of known point-like sources. The study highlights that heavier nuclei in cosmic rays can significantly affect $\gamma$-ray detection performance, particularly at lower energies. The authors demonstrate that their method for calculating sensitivity to point-like sources is effective and reliable by applying it to known sources and comparing their results with previous studies. They also provide estimates for observation times required to achieve firm detections on these sources using ALTO. This paper provides valuable insights into improving $\gamma$-ray detection performance in atmospheric shower arrays by accounting for heavier nuclei in cosmic rays and developing an effective method for calculating sensitivity to point-like sources. These findings have important implications for future research in high-energy astrophysics and could lead to significant advancements in our understanding of the universe's most energetic phenomena.