Analysis of GeV-band gamma-ray emission from SNR RX J1713.7-3946

Abstract

RX J1713.7-3946 is the brightest shell-type Supernova remnant (SNR) of the TeV gamma-ray sky. Earlier Fermi-LAT results on low-energy gamma-ray emission suggested that, despite large uncertainties in the background determination, the spectrum is inconsistent with a hadronic origin. We update the GeV-band spectra using improved estimates for the diffuse galactic gamma-ray emission and more than doubled data volume. We further investigate the viability of hadronic emission models for RX J1713.7-3946. We produced a high-resolution map of the diffuse Galactic gamma-ray background corrected for HI self-absorption and used it in the analysis of more than 5~years worth of Fermi-LAT data. We used hydrodynamic scaling relations and a kinetic transport equation to calculate the acceleration and propagation of cosmic-rays in SNR. We then determined spectra of hadronic gamma-ray emission from RX J1713.7-3946, separately for the SNR interior and the cosmic-ray precursor region of the forward shock, and computed flux variations that would allow to test the model with observations. We find that RX J1713.7-3946 is now detected by Fermi-LAT with very high statistical significance, and the source morphology is best described by that seen in the TeV band. The measured spectrum of RX J1713.7-3946 is hard with index gamma=1.53 +/- 0.07, and the integral flux above 500 MeV is F = (5.5 +/- 1.1)e-9 photons/cm^2/s. We demonstrate that scenarios based on hadronic emission from the cosmic-ray precursor region are acceptable for RX J1713.7-3946, and we predict a secular flux increase at a few hundred GeV at the level of around 15% over 10 years, which may be detectable with the upcoming CTA observatory.

9 pages, accepted for publication in Astronomy & Astrophysics

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• Global cosmic-ray related luminosity and energy budget of the Milky Way
• Observations of the young supernova remnant RX J1713.7-3946 with the Fermi Large Area Telescope
• Study of Nonthermal Emission from SNR RX J1713.7-3946 with Suzaku
• Hadronic gamma-rays from RX J1713.7-3946?
• 3D Distribution of Molecular Gas in the Barred Milky Way
• Magnetic-Field Amplification in the Thin X-ray Rims of SN1006
• Reacceleration of electrons in supernova remnants
• The properties of non-thermal X-ray filaments in young supernova remnants

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• Non-thermal emission from the reverse shock of the youngest galactic Supernova remnant G1.9+0.3
• Evolution of High-Energy Particle Distribution in Mature Shell-Type Supernova Remnants
• Discovery of a shock-compressed magnetic field in the north-western rim of the young supernova remnant RX J1713.7-3946 with X-ray polarimetry
• Simulating TeV gamma-ray morphologies of shell-type supernova remnants
• 4FGL J1844.4-0306: high-energy emission likely from the supernova remnant G29.37+0.1
• Gamma-ray Emission of the Kes 73/1E 1841-045 Region Observed with the Fermi Large Area Telescope
• Detection of the extended $\gamma$-ray emission from the high Galactic latitude Calvera's SNR candidate
• Radial Profiles of Non-thermal Emission from Supernova Remnant RX J1713.7-3946
• A Possible Gamma-Ray Enhancement Event in Tycho's Supernova Remnant
• Assessing the Impact of Hydrogen Absorption on the Characteristics of the Galactic Center Excess