Gamma-ray observation towards the young massive star cluster NGC 6618 in the M17 region

TL;DR

This paper reports the detection of gamma-ray emissions near the young star cluster NGC 6618, revealing two components with distinct spectral features, indicating cosmic ray propagation effects unique to this cluster.

Contribution

First detection of gamma-ray emissions from NGC 6618, showing distinct spectral components and suggesting cosmic ray acceleration and propagation effects.

Findings

Detection of gamma-ray emissions near NGC 6618

Identification of point-like and extended components with different spectra

Implication of cosmic ray propagation effects in the cluster

Abstract

Young massive clusters have been established as a new population of gamma-ray sources and potential cosmic ray (CR) accelerators. In this paper, we report the detection of gamma-ray emissions near the young star cluster NGC 6618, which is one of the youngest star clusters in our Galaxy. The detected gamma-ray emissions can be divided into two components. One component is point-like and reveals harder spectrum, while the other is extended and with softer spectrum. Such spectral features are significantly different from other young massive clusters and may be due to the propagation effects of CRs accelerated in NGC 6618.