The Environment around the Young Massive Star Cluster RSGC 1 and HESS J1837-069

Abstract

We report on Mopra observations toward the young massive star cluster RSGC 1, adjoined by, and possibly associated with the gamma-ray source HESS J1837-069. We measure the CO (J=1-0) distribution around the cluster and gamma-ray source, and find that the cluster is slightly higher than the velocity ranges associated with the Crux-Scutum arm. We reveal the cluster is associated with much less molecular gas compared with other young massive clusters in the Galaxy, Westerlund 1 (Wd 1) and 2 (Wd 2), which also radiate gamma-rays. We find no other structures that would otherwise indicate the action of supernova remnants, and due to the lack of material which may form gamma-rays by hadronic interaction, we conclude that the gamma-rays detected from HESS J1837-069 are not created through proton-proton interactions, and may more plausibly originate from the pulsar that was recently found near RSGC 1.

Accepted for publication in PASJ

References in corpus (8)

• Outer structure of the Galactic warp and flare: explaining the Canis Major over-density
• Molecular clouds towards RCW 49 and Westerlund 2; Evidence for cluster formation triggered by cloud-cloud collision
• Discovery of an Extraordinarily Massive Cluster of Red Supergiants
• The cool supergiant population of the massive young star cluster RSGC1
• Detection of extended very-high-energy gamma-ray emission towards the young stellar cluster Westerlund 2
• Nonthermal X-rays from low-energy cosmic rays: Application to the 6.4 keV line emission from the Arches cluster region
• Discovery of a Young, Energetic 70.5 ms Pulsar Associated with the TeV Gamma-ray Source HESS J1837-069
• The distance to the young open cluster Westerlund 2

Cited by in corpus (2)

• Diffuse gamma-ray emission from the vicinity of young massive star cluster RSGC 1
• An interacting molecular cloud scenario for production of gamma-rays and neutrinos from MAGIC J1835-069, and MAGIC J1837-073