Observation of the galactic PeVatron candidate LHAASO J2108+5157 with the Large-Sized Telescope for Cherenkov Telescope Array

TL;DR

This paper reports the first observations of the galactic PeVatron candidate LHAASO J2108+5157 with the LST-1 telescope, constraining its multi-TeV gamma-ray emission and exploring particle acceleration scenarios.

Contribution

It provides new observational constraints on a galactic PeVatron candidate using CTA's LST-1 and multi-wavelength data, advancing understanding of high-energy cosmic accelerators.

Findings

Strong constraints on the source emission in the multi-TeV band.

Multi-wavelength modeling with 12-year Fermi-LAT and XMM-Newton data.

Testing of different particle acceleration scenarios.

Abstract

The Cherenkov Telescope Array (CTA) Observatory will be the next-generation ground-based very-high-energy gamma-ray observatory, sensitive from 20 GeV up to 300 TeV. The Large-Sized Telescope prototype (LST-1), currently in the commissioning phase, was inaugurated in October 2018 on La Palma (Spain). It is the first of four LST telescopes for CTA, to be built in La Palma. In 2021, LST-1 performed observations of one of the Galactic PeVatron candidates, LHAASO J2108+5157, recently discovered by the LHAASO collaboration. We present results of our analysis of the LST-1 data, putting strong constraints on the emission of the source in the multi-TeV band. We also present results of multi-wavelength modeling using 12-years Fermi-LAT data and Target of Opportunity observations with XMM-Newton. We test different scenarios for the parent particles producing the high energy emission and put constraints on their spectra.