Observations of the Fermi bubbles and the Galactic center excess with the DArk Matter Particle Explorer

Authors:
  • FAF. Alemanno
    F. Alemanno
  • QAQ. An
    Q. An
  • PAP. Azzarello
    P. Azzarello
  • FBF. C. T. Barbato
    F. C. T. Barbato
  • PBP. Bernardini
    P. Bernardini
  • XBX. J. Bi
    X. J. Bi
  • HBH. Boutin
    H. Boutin
  • ICI. Cagnoli
    I. Cagnoli
  • MCM. S. Cai
    M. S. Cai
  • ECE. Casilli
    E. Casilli
  • JCJ. Chang
    J. Chang
  • DCD. Y. Chen
    D. Y. Chen

Abstract
The DArk Matter Particle Explorer (DAMPE) is a space-borne high-energy particle detector that surveys the $γ$-ray sky above$\sim 2~\rm GeV$ with a peak acceptance of $\sim 0.2~\rm m^2\,sr$. With the 102 months of data collected by DAMPE, we show that the Fermi bubbles are detected at a significance of $\sim 26σ$ and identify a GeV excess in the direction of Galactic center at $\sim 7 σ$ confidence. Both spectra and morphology are consistent with those observed by Fermi-LAT and the GeV excess component can be interpreted by the dark matter annihilation with a mass of $\sim 50$ GeV and a velocity-averaged cross section of $\sim 10^{-26}~{\rm cm^{3}~s^{-1}}$ for the $χχ\rightarrow b\bar{b}$ channel. Our results thus provide the first independent detection of these two intriguing diffuse gamma-ray sources besides Fermi-LAT.