Recently , Daylan et al .
( 2014 ) show that the GeV gamma-ray excess signal from the central Milky Way can be explained by the annihilation of \sim 40 GeV dark matter through b \bar { b } channel .
Based on the morphology of the gamma-ray flux , the best-fit inner slope of the dark matter density profile is \gamma = 1.26 .
However , recent analyses of Milky Way dark matter profile favor \gamma = 0.6 - 0.8 .
In this article , we show that the GeV gamma-ray excess can also be explained by the Sommerfeld-enhanced dark matter annihilation through b \bar { b } channel with \gamma = 0.85 - 1.05 .
We constrain the parameters of the Sommerfeld-enhanced annihilation by using the data from Fermi-LAT .
We also show that the predicted gamma-ray fluxes emitted from dwarf galaxies generally satisfy the recent upper limits of gamma-ray fluxes detected by Fermi-LAT .