Gamma-Ray Observations of the Supernova Remnant RX J0852.0-4622 with the Fermi LAT

TL;DR

This paper reports gamma-ray observations of the supernova remnant RX J0852.0-4622 using Fermi LAT, identifying it as an extended source with a spectrum consistent with hadronic emission, and discusses possible emission mechanisms.

Contribution

First detailed gamma-ray analysis of RX J0852.0-4622 with Fermi LAT, confirming its spatial extension and exploring hadronic and leptonic emission models.

Findings

Gamma-ray source is spatially extended and matches the SNR size.

Spectrum fits a power law with photon index 1.85, connecting to TeV data.

Hadronic model explains gamma-ray emission well.

Abstract

We report on gamma-ray observations of the supernova remnant (SNR) RX J0852.0-4622 with the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope. In the Fermi LAT data, we find a spatially extended source at the location of the SNR. The extension is consistent with the SNR size seen in other wavelengths such as X-rays and TeV gamma rays, leading to the identification of the gamma-ray source with the SNR. The spectrum is well described as a power law with a photon index of Gamma = 1.85 +/- 0.06 (stat) (+0.18,-0.19) (sys), which smoothly connects to the H.E.S.S. spectrum in the TeV energy band. We discuss the gamma-ray emission mechanism based on multiwavelength data. The broadband data can be fit well by a model in which the gamma rays are of hadronic origin. We also consider a scenario with inverse Compton scattering of electrons as the emission mechanism of the gamma rays. Although the leptonic model predicts a harder spectrum in the Fermi LAT energy range, the model can fit the data considering the statistical and systematic errors.