The dark connection between the Canis Major dwarf, the Monoceros ring, the gas flaring, the rotation curve and the EGRET excess of diffuse Galactic Gamma Rays

TL;DR

This paper links the diffuse gamma-ray excess observed by EGRET to dark matter annihilation, correlating it with the Monoceros ring, gas flaring, and Milky Way rotation, suggesting a unified galactic structure explanation.

Contribution

It proposes a novel connection between gamma-ray excess, dark matter distribution, and the Monoceros ring, supported by observational and simulation data.

Findings

Gamma-ray excess consistent with WIMP annihilation at 50-100 GeV

Halo profile with substructure matching N-body simulations

Outer ring's gravitational effects align with gas flaring and rotation data

Abstract

The excess of diffuse galactic gamma rays above 1 GeV, as observed by the EGRET telescope on the NASA Compton Gamma Ray Observatory, shows all the key features from Dark Matter (DM) annihilation: (i) the energy spectrum of the excess is the same in all sky directions and is consistent with the gamma rays expected for the annihilation of WIMPs with a mass between 50-100 GeV; (ii) the intensity distribution of the excess in the sky is used to determine the halo profile, which was found to correspond to the usual profile from N-body simulations with additional substructure in the form of two doughnut-shaped structures at radii of 4 and 13 kpc; (iii) recent N-body simulations of the tidal disruption of the Canis Major dwarf galaxy show that it is a perfect progenitor of the ringlike Monoceros tidal stream of stars at 13 kpc with ring parameters in agreement with the EGRET data; (iiii) the mass of the outer ring is so large, that its gravitational effects influence both the gas flaring and the rotation curve of the Milky Way. Both effects are clearly observed in agreement with the DMA interpretation of the EGRET excess.