Intensity mapping cross-correlations II: HI halo models including shot noise

Abstract

H I intensity mapping data traces the large-scale structure matter distribution using the integrated emission of neutral hydrogen gas (H I). Cross-correlation of the intensity maps with optical galaxy surveys can mitigate foreground and systematic effects, but has been shown to significantly depend on galaxy evolution parameters of the H I and the optical sample. Previously, we have shown that the shot noise of the cross-correlation scales with the H I content of the optical samples, such that the shot noise estimation infers the average H I masses of these samples. In this paper, we present an adaptive framework for the cross-correlation of H I intensity maps with galaxy samples using our i..