Inhomogeneity in the Supernova Remnant Distribution as the Origin of the PAMELA Anomaly

Abstract

Recent measurements of the positron/electron ratio in the cosmic ray (CR) flux exhibits an apparent anomaly, whereby this ratio increases between 10 and 100 GeV. We show that inhomogeneity of CR sources on a scale of order a kpc, can naturally explain this anomaly. If the nearest major CR source is about a kpc away, then low energy electrons ($\sim 1$ GeV) can easily reach us. At higher energies ($\gtrsim 10$ GeV), the source electrons cool via synchrotron and inverse-Compton before reaching Earth. Pairs formed in the local vicinity through the proton/ISM interactions can reach Earth also at high energies, thus increasing the positron/electron ratio. A natural origin of source inhomogeneity is the strong concentration of supernovae in the galactic spiral arms. Assuming supernova remnants (SNRs) as the sole primary source of CRs, and taking into account their concentration near the galactic spiral arms, we consistently recover the observed positron fraction between 1 and 100 GeV. ATIC's electron excess at $\sim 600$ GeV is explained, in this picture, as the contribution of a few known nearby SNRs. The apparent coincident similarity between the cooling time of electrons at 10 GeV (where the positron/electron ratio upturn), $\sim 10$ Myr, and the CRs protons cosmogenic age at the same energy is predicted by this model.

References in corpus (19)

• Observation of an anomalous positron abundance in the cosmic radiation
• Propagation of cosmic-ray nucleons in the Galaxy
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• Production and propagation of cosmic-ray positrons and electrons
• The energy spectrum of cosmic-ray electrons at TeV energies
• A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation
• Pulsars as the Sources of High Energy Cosmic Ray Positrons
• High-energy particle acceleration in the shell of a supernova remnant
• TeV Gamma Rays from Geminga and the Origin of the GeV Positron Excess
• Cosmic-ray positron fraction measurement from 1 to 30 GeV with AMS-01
• New Positron Spectral Features from Supersymmetric Dark Matter - a Way to Explain the PAMELA Data?
• Discovery of TeV Gamma Rays from SN1006: Further Evidence for the SNR Origin of Cosmic Rays
• The Most Likely Sources of High Energy Cosmic-Ray Electrons in Supernova Remnants
• New Measurement of the Cosmic-Ray Positron Fraction from 5 to 15 GeV
• The Spiral Structure of the Milky Way, Cosmic Rays, and Ice Age Epochs on Earth
• Galactic secondary positron flux at the Earth
• Cosmic Ray Diffusion from the Galactic Spiral Arms, Iron Meteorites, and a possible climatic connection?
• Decaying Dark Matter and the PAMELA Anomaly
• Possible causes of a rise with energy of the cosmic ray positron fraction

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• On cosmic ray acceleration in supernova remnants and the FERMI/PAMELA data
• Inverse Compton constraints on the Dark Matter e+e- excesses
• Using HAWC to Discover Invisible Pulsars
• High-Energy Gamma Rays from the Milky Way: Three-Dimensional Spatial Models for the Cosmic-Ray and Radiation Field Densities in the Interstellar Medium
• Indirect Searches for Decaying Dark Matter
• Three-Dimensional Model of Cosmic-Ray Lepton Propagation Reproduces Data from the Alpha Magnetic Spectrometer on the International Space Station
• $e^{\pm }$ Excesses in the Cosmic Ray Spectrum and Possible Interpretations
• Relic density and CMB constraints on dark matter annihilation with Sommerfeld enhancement
• Neutrino Signals from Dark Matter Decay
• Positron flux and gamma-ray emission from Geminga pulsar and pulsar wind nebula
• AMS-02 positron excess: new bounds on dark matter models and hint for primary electron spectrum hardening
• W/Z Bremsstrahlung as the Dominant Annihilation Channel for Dark Matter
• Galactic cosmic-ray propagation in the light of AMS-02: I. Analysis of protons, helium, and antiprotons
• White Dwarf Pulsars as Possible Cosmic Ray Electron-Positron Factories
• Cosmic-Ray Electron Excess from Pulsars is Spiky or Smooth?: Continuous and Multiple Electron/Positron injections
• The origin of the spectral intensities of cosmic-ray positrons
• Neutrino Mass and Dark Matter in light of recent AMS-02 results
• Radio and gamma-ray constraints on dark matter annihilation in the Galactic center
• Dark Matter Annihilation Signatures from Electroweak Bremsstrahlung
• Implications of the Cosmic Ray Electron Spectrum and Anisotropy measured with Fermi-LAT
• CosRayMC: a global fitting method in studying the properties of the new sources of cosmic e${}^{\pm }$ excesses
• What can we really learn from positron flux 'anomalies'?
• Cosmic-ray positrons from millisecond pulsars
• Anti-deuterons from heavy Dark Matter
• Propagation in 3D spiral-arm cosmic-ray source distribution models and secondary particle production using PICARD
• A Gamma-Ray Burst/Pulsar for Cosmic-Ray Positrons with a Dark Matter-like Spectrum
• Positrons from Primordial Black Hole Microquasars and Gamma-ray Bursts
• Sneutrino Dark Matter: Symmetry Protection and Cosmic Ray Anomalies
• Intermediate Mass Black Holes and Nearby Dark Matter Point Sources: A Critical Reassessment
• Constraining Decaying Dark Matter with Fermi LAT Gamma-rays
• Antimatter production in supernova remnants
• The `excess' of primary cosmic ray electrons
• Study of the Gamma-ray Spectrum from the Galactic Center in view of Multi-TeV Dark Matter Candidates
• Spatial Dependent Diffusion of Cosmic Rays and the Excess of Primary Electrons Derived from High Precision Measurements by AMS-02
• The Morphology of the Galactic Dark Matter Synchrotron Emission with Self-Consistent Cosmic Ray Diffusion Models
• Recovering the observed B/C ratio in a dynamic spiral-armed cosmic ray model
• Impact of the spectral hardening of TeV cosmic rays on the prediction of the secondary positron flux
• Electrons and Positrons in Cosmic Rays
• Astrophysical Implications of a Visible Dark Matter Sector from a Custodially Warped-GUT
• Pulsars as the Source of the WMAP Haze
• Cosmic Ray Anomalies and Dark Matter Annihilation to Muons via a Higgs Portal Hidden Sector
• Positrons in Cosmic Rays from Dark Matter Annihilations for Uplifted Higgs Regions in MSSM
• Reconciling the diffuse Galactic gamma-ray and the cosmic ray spectra
• Clumpiness enhancement of charged cosmic rays from dark matter annihilation with Sommerfeld effect
• A self-consistent model of cosmic-ray fluxes and positron excess: Roles of nearby pulsars and a sub-dominant source population
• The B/C and sub-Iron/Iron Cosmic ray ratios - further evidence in favor of the spiral arm diffusion model
• Implications of dark matter cascade decay from DAMPE, HESS, Fermi-LAT and AMS02 data
• On discrepancy between ATIC and Fermi data
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• TeV cosmic-ray proton and helium spectra in the myriad model II
• Extracting the size of the cosmic electron-positron anomaly
• On the PeV knee of cosmic rays spectrum and TeV cutoff of electron spectrum
• $e^{+}$ and $\bar{p}$ production in $pp$ collisions and the cosmic-ray $e^{+}/\bar{p}$ flux ratio
• The Contribution of Millisecond Pulsars to the Galactic Cosmic-Ray Lepton Spectrum
• Cosmic ray backgrounds for dark matter indirect detection
• Cosmic-ray Electron and Positron Excesses from Hidden Gaugino Dark Matter
• Multi messenger astronomy and CTA: TeV cosmic rays and electrons
• Cosmic Rays in the Milky Way and Beyond
• Constraining the Milky Way's Pulsar Population with the Cosmic-Ray Positron Fraction
• Cosmic positron and antiproton constraints on the gauge-Higgs Dark Matter
• Positron annihilation as a cosmic-ray probe
• Dark Matter Annihilation and the PAMELA, FERMI and ATIC Anomalies
• Origin Of The Cosmic Ray Positrons Observed Near Earth- Meson Decay Or Dark Matter Decay?
• Probing the astrophysical origin of high-energy cosmic-ray electrons with Monte Carlo simulation
• On the use of X-ray and gamma-ray telescopes for identifying the origin of electrons and positrons observed by ATIC, Fermi, and PAMELA
• Is PSR J0855$-$4644 responsible for the 1.4 TeV electron spectral bump hinted by DAMPE?
• Average Inhomogeneities in Milky Way SNII and The PAMELA Anomaly
• Dark matter in natural supersymmetric extensions of the Standard Model
• Electron-Capture Isotopes could Constrain Cosmic-Ray Propagation Models
• Inverse Compton gamma-rays from Galactic dark matter annihilation: Anisotropy signatures
• Signatures of dark matter annihilation in the light of PAMELA/ATIC anomaly
• Pulsar Wind Nebulae as a source of the observed electron and positron excess at high energy: the case of Vela-X