Diffuse $\gamma$-ray emission around the massive star forming region of Carina Nebula Complex
| Autor: | Ting-Ting Ge, Xiao-Na Sun, Rui-Zhi Yang, Yun-Feng Liang, En-Wei Liang |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Popis: | We report the Fermi Large Area Telescope (Fermi-LAT) detection of the $\gamma$-ray emission toward the massive star forming region of Carina Nebula Complex (CNC). Using the latest source catalog and diffuse background models, we found that the GeV $\gamma$-ray emission in this region can be resolved into three different components. The GeV $\gamma$-ray emission from the central point source is considered to originate from the Eta Carina ($\eta$ Car). We further found the diffuse GeV $\gamma$-ray emission around the CNC which can be modelled by two Gaussian disks with radii of 0.4\deg (region A) and 0.75\deg (region B), respectively. The GeV $\gamma$-ray emission from both the regions A and B have good spatial consistency with the derived molecular gas in projection on the sky. The GeV $\gamma$-ray emission of region A reveals a characteristic spectral shape of the pion-decay process, which indicates that the $\gamma$-rays are produced by the interactions of hadronic cosmic rays with ambient gas. The $\gamma$-rays spectrum of region B has a hard photon index of 2.12 $\pm$ 0.02, which is similar to other young massive star clusters. We argue that the diffuse GeV $\gamma$-ray emission in region A and region B likely originate from the interaction of accelerated protons in clusters with the ambient gas. Comment: 8 pages, 7 figures. Accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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