On the Galactic Center Being the Main Source of Galactic Cosmic Rays as Evidenced by Recent Cosmic Ray and Gamma Ray Observations

Abstract

We revisit the idea that the Galactic center (GC) is the dominant source of Galactic cosmic rays (GCRs), based on a series of new observational evidence. A unified model is proposed to explain the new phenomena of GCRs and $\gamma$-rays simultaneously. The GCRs are thought to be accelerated during past activities of the GC. The pair production process of GCRs in the strong radiation field due to the GC activity is responsible for the knee structure of the cosmic ray spectra. A f raction of $e^{+}{e}^{-}$ produced by pair production interactions, can be reaccelerated in the induced bipolar jets and be transported into the halo, leaving the Fermi $\gamma$-ray bubbles and WMAP microwave haze as the remnant signal. Finally, the CRs diffuse in the bulge could further interact with the interstellar medium to produce low energy $e^{+}{e}^{-}$. After cooling down, these positrons may annihilate to produce the 511 keV line emission as discovered by INTEGRAL.

References in corpus (21)

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Cited by in corpus (9)

• Northern sky Galactic Cosmic Ray anisotropy between 10-1000 TeV with the Tibet Air Shower Array
• Spatial-Dependent Diffusion of Cosmic Rays and the Ratio of pbar/p, B/C
• Galactic Cosmic-Ray Anisotropy in the Northern hemisphere from the ARGO-YBJ Experiment during 2008-2012
• The Galactic Center: A PeV Cosmic Ray Acceleration Factory
• Pinpointing the knee of cosmic rays with diffuse PeV gamma-rays and neutrinos
• Extracting the size of the cosmic electron-positron anomaly
• New prototype scintillator detector for the Tibet AS$\gamma$ Experiment
• Galactic Centre as an efficient source of cosmic rays
• Correlation of high energy neutrinos and gamma rays on the direction of Fermi Bubbles