Gamma-Rays Produced in Cosmic-Ray Interactions and the TeV-band Spectrum of RX J1713-3946

Abstract

In this work we study the individual contribution to diffuse $\gamma$-ray emission from the secondary products in hadronic interactions generated by cosmic rays (CRs), in addition to the contribution of ${\pi }^0$ decay via the decay mode ${\pi }^0\to 2\gamma$. For that purpose we employ the Monte Carlo particle collision code DPMJET3.04 to determine the multiplicity spectra of various secondary particles with $\gamma$'s as the final decay state, that result from inelastic collisions between cosmic-ray protons and Helium nuclei and the interstellar medium with standard composition. We thus derive an easy-to-use $\gamma$-ray production matrix for cosmic ray up to about 10 PeV, that can be used to interpret the $\gamma$-ray spectra of diffuse galactic emission and supernova remnants (SNR). We apply the $\gamma$-ray production matrix to the GeV excess in diffuse galactic $\gamma$-rays that was seen with EGRET. Although the non-${\pi }^0$ contributions to the total emission have a different spectrum than the ${\pi }^0$-decay component, they are insufficient to explain the GeV excess. We also test the hypothesis that the TeV-band $\gamma$-ray emission of the shell-type SNR RX J1713-3946, that was observed with HESS, is caused by shock-accelerated hadronic cosmic rays. This scenario implies a very high efficacy of particle acceleration, so the particle spectrum is expected to continuously harden toward high energies on account of cosmic-ray modification of the shock. Using the ${\chi }^2$ statistic we find that a continuously softening spectrum is strongly preferred, in contrast to expectations. A hardening spectrum has about 1% probability to explain the HESS data, but then only if a hard cut-off at 50-100 TeV is imposed on the particle spectrum.

minor revision; Astropart. Phys. in press

References in corpus (25)

• Energy spectra of gamma-rays, electrons and neutrinos produced at proton-proton interactions in the very high energy regime
• BL Lac Objects in the Synchrotron Proton Blazar Model
• Diffuse Galactic continuum gamma rays. A model compatible with EGRET data and cosmic-ray measurements
• High-energy particle acceleration in the shell of a supernova remnant
• A Proton Synchrotron Blazar Model for Flaring in Markarian~501
• Parameterization of Gamma, e^+/- and Neutrino Spectra Produced by p-p Interaction in Astronomical Environment
• A detailed spectral and morphological study of the gamma-ray supernova remnant RX J1713.7-3946 with H.E.S.S
• Detection of TeV gamma-ray Emission from the Shell-Type Supernova Remnant RX J0852.0-4622 with H.E.S.S
• Non linear particle acceleration at non-relativistic shock waves in the presence of self-generated turbulence
• XMM-Newton observations of the supernova remnant RX J1713.7-3946 and its central source
• Extensive Air Shower Simulations at the Highest Energies
• Electron acceleration in SNR and diffuse gamma-rays above 1 GeV
• The Galactic Diffuse Gamma-ray Spectrum from Cosmic-ray Proton Interactions
• High energy gamma-ray emission from the starburst nucleus of NGC 253
• A Detailed Study of Molecular Clouds toward the TeV Gamma-Ray SNR G347.3-0.5
• Parametrizations of Inclusive Cross Sections for Pion Production in Proton-Proton Collisions
• Diffractive Interaction and Scaling Violation in pp->pi^0 Interaction and GeV Excess in Galactic Diffuse Gamma-Ray Spectrum of EGRET
• Cosmic-ray propagation properties for an origin in SNRs
• Cosmic Rays and Particle Physics
• No evidence yet for hadronic TeV gamma-ray emission from SNR RX J1713.7-3946
• Broad-band diffuse gamma ray emission of the Galactic Disk
• RXTE, ROSAT and ASCA Observations of G347.3-0.5 (RX J1713.7-3946): Probing Cosmic Ray Acceleration by a Galactic Shell-Type Supernova Remnant
• Modeling the Multiwavelength Spectra and Variability of BL Lacertae in 2000
• Atmospheric neutrino flux from 3-dimensional simulation
• Atmospheric gamma-ray observation with the BETS detectorfor calibrating atmospheric neutrino flux calculations

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• Evidence for proton acceleration up to TeV energies based on VERITAS and Fermi-LAT observations of the Cas A SNR
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• Time-Dependent Escape of Cosmic Rays from Supernova Remnants, and their Interaction with Dense Media
• Acceleration of cosmic rays by young core-collapse supernova remnants
• Production of secondary particles and nuclei in cosmic rays collisions with the interstellar gas using the FLUKA code
• The GeV-TeV Galactic gamma-ray diffuse emission I. Uncertainties in the predictions of the hadronic component
• Explaining cosmic ray antimatter with secondaries from old supernova remnants
• Non-Thermal X-ray Emission from the Northwestern Rim of the Galactic Supernova Remnant G266.2-1.2 (RX J0852.0-4622)
• Analysis of GeV-band gamma-ray emission from SNR RX J1713.7-3946
• Systematic study of the uncertainties in fitting the cosmic positron data by AMS-02
• Diffuse Galactic Gamma Rays from Shock-Accelerated Cosmic Rays
• Origin of Ultrahigh Energy Galactic Cosmic Rays: The Isotropy Problem
• Astrophysical Limits on Lorentz Violation for Pions
• Implications of a possible TeV break in the cosmic-ray electron and positron flux
• Production of Neutrinos and Secondary Electrons in Cosmic Sources
• Production of secondary particles in heavy nuclei interactions in supernova remnants
• On the Physics Connecting Cosmic Rays and Gamma Rays: Towards Determining the Interstellar Cosmic Ray Spectrum
• A signature of EeV protons of Galactic origin
• Stochastic re-acceleration and magnetic-field damping in Tycho's supernova remnant
• Interpreting the GeV-TeV Gamma-Ray Spectra of Local Giant Molecular Clouds using GEANT4 Simulation
• Monte Carlo Study of Cosmic-Ray Propagation in the Galaxy and Diffuse Gamma-Ray Production
• Angular Distribution of Gamma Rays Produced in Proton-Proton Collisions
• Interacting supernovae and where to find them