Minkowski Functionals of CII Line Intensity Maps: Probing Astrophysics and Primordial Features

Abstract: Line intensity mapping aims to measure the total cumulative light of spectral lines from galaxies, without resolving individual sources. In this work, we investigate mock intensity maps of ionized carbon CII using Minkowski functionals, which capture the morphological properties of the maps. We generate semi-numerical simulations of CII intensity maps at $z\approx 6$ and $7.6$, adopting an astrophysical model that relates CII line luminosity to the mass of the host dark matter halos. We find that Minkowski functionals can provide tight constraints on the astrophysical model parameters in the presence of noise characteristics expected from the upcoming CCAT survey. We further investigate the prospects of probing a bump-like feature superimposed on the standard single power-law primordial power spectrum. Using a Fisher matrix formalism, we demonstrate that the effects of this primordial feature can be disentangled from those of the astrophysical model parameters. Combining measurements across multiple smoothing scales as well as redshifts can further improve the constraints and enhance the prospects for detecting such primordial features.