TY  - JOUR
A1  - Macias, Oscar
A1  - Gordon, Chris
A1  - Crocker, Roland M.
A1  - Coleman, Brendan
A1  - Paterson, Dylan
A1  - Horiuchi, Shunsaku
A1  - Pohl, Martin
T1  - Galactic bulge preferred over dark matter for the Galactic centre gamma-ray excess
JF  - Nature Astronomy
N2  - An anomalous gamma-ray excess emission has been found in the Fermi Large Area Telescope data1 covering the centre of the Galaxy2,3. Several theories have been proposed for this ‘Galactic centre excess’. They include self-annihilation of dark-matter particles4, an unresolved population of millisecond pulsars5, an unresolved population of young pulsars6, or a series of burst events7. Here, we report on an analysis that exploits hydrodynamical modelling to register the position of interstellar gas associated with diffuse Galactic gamma-ray emission. We find evidence that the Galactic centre excess gamma rays are statistically better described by the stellar over-density in the Galactic bulge and the nuclear stellar bulge, rather than a spherical excess. Given its non-spherical nature, we argue that the Galactic centre excess is not a dark-matter phenomenon but rather associated with the stellar population of the Galactic bulge and the nuclear bulge.
Y1  - 2018
U6  - https://doi.org/10.1038/s41550-018-0414-3
SN  - 2397-3366
VL  - 2
IS  - 5
SP  - 387
EP  - 392
PB  - Nature Publ. Group
CY  - London
ER  -