Explaining cosmic ray antimatter with secondaries from old supernova remnants

Abstract

Despite significant efforts over the past decade, the origin of the cosmic ray positron excess has still not been unambiguously established. A popular class of candidate sources are pulsars or pulsar wind nebulae but these cannot also account for the observed hard spectrum of cosmic ray antiprotons. We revisit the alternative possibility that the observed high-energy positrons are secondaries created by spallation in supernova remnants during the diffusive shock acceleration of the primary cosmic rays, which are further accelerated by the same shocks. The resulting source spectrum of positrons at high energies is then naturally harder than that of the primaries, as is the spectrum of other secondaries such as antiprotons. We present the first comprehensive investigation of the full parameter space of this model -- both the source parameters as well as those governing galactic transport. Various parameterisations of the cross sections for the production of positrons and antiprotons are considered, and the uncertainty in the model parameters discussed. We obtain an excellent fit to recent precision measurements by AMS-02 of cosmic ray protons, helium, positrons and antiprotons, as well as of various primary and secondary nuclei. This model thus provides an economical explanation of the spectra of all secondary species -- from a single well-motivated population of sources.

arXiv comment10 pages, 5 figures

References in corpus (48)

• emcee: The MCMC Hammer
• Observation of an anomalous positron abundance in the cosmic radiation
• EPOS LHC : test of collective hadronization with LHC data
• Propagation of cosmic-ray nucleons in the Galaxy
• Production and propagation of cosmic-ray positrons and electrons
• Pulsars as the Sources of High Energy Cosmic Ray Positrons
• Extended gamma-ray sources around pulsars constrain the origin of the positron flux at Earth
• Parameterization of Gamma, e^+/- and Neutrino Spectra Produced by p-p Interaction in Astronomical Environment
• TeV Gamma Rays from Geminga and the Origin of the GeV Positron Excess
• Dissipation of Magnetohydrodynamic Waves on Energetic Particles: Impact on Interstellar Turbulence and Cosmic Ray Transport
• The origin of the positron excess in cosmic rays
• Production of pions, kaons and protons in pp collisions at $\sqrt{s}=900$ GeV with ALICE at the LHC
• Global cosmic-ray related luminosity and energy budget of the Milky Way
• Spectral breaks as a signature of cosmic ray induced turbulence in the Galaxy
• On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
• The origin of Galactic cosmic rays: challenges to the standard paradigm
• On cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data
• Dissecting cosmic-ray electron-positron data with Occam's Razor: the role of known Pulsars
• Testing astrophysical models for the PAMELA positron excess with cosmic ray nuclei
• Using HAWC to Discover Invisible Pulsars
• Current status and desired accuracy of the isotopic production cross sections relevant to astrophysics of cosmic rays I. Li, Be, B, C, N
• AMS-02 data confronts acceleration of cosmic ray secondaries in nearby sources
• Detection of a $\gamma$-ray halo around Geminga with the Fermi-LAT and implications for the positron flux
• Inference of the Local Interstellar Spectra of Cosmic Ray Nuclei Z<=28 with the GalProp-HelMod Framework
• Bayesian analysis of spatial-dependent cosmic-ray propagation: astrophysical background of antiprotons and positrons
• Cosmic Ray Antiprotons at High Energies
• Production of Mesons and Baryons at High Rapidity and High Pt in Proton-Proton Collisions at sqrt(s) = 200 GeV
• AMS-100: The Next Generation Magnetic Spectrometer in Space -- An International Science Platform for Physics and Astrophysics at Lagrange Point 2
• Cosmic-ray propagation with DRAGON2: II. Nuclear interactions with the interstellar gas
• New calculation of antiproton production by cosmic ray protons and nuclei
• Galactic factories of cosmic-ray electrons and positrons
• Combined analysis of AMS-02 (Li,Be,B)/C, N/O, 3He, and 4He data
• Parametrizations of Inclusive Cross Sections for Pion Production in Proton-Proton Collisions
• Cosmic ray production in supernova remnants including reacceleration: the secondary to primary ratio
• Dark matter or correlated errors: Systematics of the AMS-02 antiproton excess
• Constraining the origin of the rising cosmic ray positron fraction with the boron-to-carbon ratio
• AMS-02 antiprotons' consistency with a secondary astrophysical origin
• Diffractive Interaction and Scaling Violation in pp->pi^0 Interaction and GeV Excess in Galactic Diffuse Gamma-Ray Spectrum of EGRET
• What can we really learn from positron flux 'anomalies'?
• Gamma-Rays Produced in Cosmic-Ray Interactions and the TeV-band Spectrum of RX J1713-3946
• Secondary Cosmic Ray Nuclei from Supernova Remnants and Constraints to the Propagation Parameters
• Breaks in interstellar spectra of positrons and electrons derived from time-dependent AMS data
• Stochastic Fluctuations of Low-Energy Cosmic Rays and the Interpretation of Voyager Data
• Parameterized total cross sections for pion production in nuclear collisions
• Antimatter production in supernova remnants
• Antideuterons in cosmic rays: sources and discovery potential
• The spectral shapes of the fluxes of electrons and positrons and the average residence time of cosmic rays in the Galaxy
• Production and acceleration of antinuclei in supernova shockwaves

Cited by in corpus (10)

• Diffuse Emission of Galactic High-Energy Neutrinos from a Global Fit of Cosmic Rays
• Grammage of cosmic rays in the proximity of supernova remnants embedded in a partially ionized medium
• Interpretations of the cosmic ray secondary-to-primary ratios measured by DAMPE
• Stochasticity of Cosmic Rays from Supernova Remnants and the Ionization Rates in Molecular Clouds
• Constraining dark matter annihilation with cosmic ray antiprotons using neural networks
• The importance of Fe fragmentation for LiBeB analyses: Is a Li primary source needed to explain AMS-02 data?
• Observing Signals of Spectral Features in the Cosmic-Ray Positrons and Electrons from Milky Way Pulsars
• Transport parameters from AMS-02 F/Si data and fluorine source abundance
• Erosion of Icy Interstellar Objects by Cosmic Rays and Implications for `Oumuamua
• New estimate for the contribution of the Geminga pulsar to the positron excess