Sensitivity of CTA to gamma-ray emission from the Perseus galaxy cluster

TL;DR

This paper evaluates the Cherenkov Telescope Array's ability to detect gamma-ray emissions from the Perseus galaxy cluster, focusing on dark matter signals and modeling substructure effects to improve sensitivity estimates.

Contribution

It presents a detailed sensitivity analysis of CTA for detecting dark matter-induced gamma rays from Perseus, including substructure modeling and an ON/OFF observation strategy.

Findings

CTA can set stringent limits on TeV dark matter decay

Substructure boosts significantly enhance detection prospects

Likelihood analysis with CTA response functions informs sensitivity estimates

Abstract

In these proceedings we summarize the current status of the study of the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. Gamma-ray emission is expected in galaxy clusters both from interactions of cosmic rays (CR) with the intra-cluster medium, or as a product of annihilation or decay of dark matter (DM) particles in case they are weakly interactive massive particles (WIMPs). The observation of Perseus has been proposed as one of the CTA Key Science Projects. In this contribution, we focus on the DM-induced component of the flux. Our DM modelling includes the substructures we expect in the main halo which will boost the annihilation signal significantly. We adopt an ON/OFF observation strategy and simulate the expected gamma-ray signals. Finally we compute the expected CTA sensitivity using a likelihood maximization analysis including the most recent CTA instrument response functions. In absence of signal, we show that CTA will allow us to provide stringent and competitive constraints on TeV DM, especially for the case of DM decay.