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arXiv · 1608.06380

Fermi Large Area Telescope Observations of the Monoceros Loop Supernova Remnant

H. Katagiri·S. Sugiyama·M. Ackermann·J. Ballet·J. M. Casandjian·Y. Hanabata·J. W. Hewitt·M. Kerr·H. Kubo·M. Lemoine-Goumard·P. S. Ray
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Abstract

We present an analysis of the gamma-ray measurements by the Large Area Telescope onboard the \textit{Fermi Gamma-ray Space Telescope} in the region of the supernova remnant~(SNR) Monoceros Loop~(G205.5$+$0.5). The brightest gamma-ray peak is spatially correlated with the Rosette Nebula, which is a molecular cloud complex adjacent to the southeast edge of the SNR. After subtraction of this emission by spatial modeling, the gamma-ray emission from the SNR emerges, which is extended and fit by a Gaussian spatial template. The gamma-ray spectra are significantly better reproduced by a curved shape than a simple power law. The luminosities between 0.2--300~GeV are $\sim$~$4 \times 10^{34}$~erg~s$^{-1}$ for the SNR and $\sim$~$3 \times 10^{34}$~erg~s$^{-1}$ for the Rosette Nebula, respectively. We argue that the gamma rays likely originate from the interactions of particles accelerated in the SNR. The decay of neutral pions produced in nucleon-nucleon interactions of accelerated hadrons with interstellar gas provides a reasonable explanation for the gamma-ray emission of both the Rosette Nebula and the Monoceros SNR.

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H. Katagiri, S. Sugiyama, M. Ackermann, J. Ballet, J. M. Casandjian, Y. Hanabata, J. W. Hewitt, M. Kerr, H. Kubo, M. Lemoine-Goumard, P. S. Ray. 2016-08-23. Fermi Large Area Telescope Observations of the Monoceros Loop Supernova Remnant. https://doi.org/10.3847/0004-637x%2F831%2F1%2F106

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