Dissecting the inner Galaxy with $\gamma$-ray pixel count statistics

Abstract

We combine adaptive template fitting and pixel count statistics in order to assess the nature of the Galactic center excess in Fermi-LAT data. We reconstruct the flux distribution of point sources well below the Fermi-LAT detection threshold, and measure their radial and longitudinal profiles in the inner Galaxy. We find that all point sources $and$ the bulge-correlated diffuse emission each contributes $\mathcal{O}$(10\%) of the total inner Galaxy emission, and disclose a potential sub-threshold point-source contribution to the Galactic center excess.

arXiv comment5+8 pages, 2+6 figures. Minor changes to match version published in PRL

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