The $\mathtt{WebSky}$ $\mathrm{[CII]}$ Forecasts and the search for primordial intermittent non-Gaussianity

TL;DR

This paper develops mock maps of [CII] emission during reionization to forecast the potential of upcoming surveys in studying primordial non-Gaussianity and improving models of cosmological line emission.

Contribution

It introduces the WebSky [CII] mock maps and uses them to forecast the capabilities of future line intensity mapping surveys in probing primordial non-Gaussianity and refining emission models.

Findings

Upcoming surveys can constrain primordial intermittent non-Gaussianity.

WebSky mocks enable better modeling of cosmological [CII] emission.

Next-generation surveys will provide competitive bounds on inflationary scenarios.

Abstract

We present the $\mathtt{WebSky}$ $\mathrm{[CII]}$ line-intensity mock maps and forecast the capabilities of upcoming wide-field submillimeter-wave surveys of cosmological $\mathrm{[CII]}$ emission from the epoch of reionization (EoR). Using the $\mathtt{Peak~Patch}$ algorithm to generate light-cone dark matter (DM) halo catalogues and the $\mathtt{WebSky}$ framework to forward-model the cosmological $\mathrm{[CII]}$ signal, we construct tomographic mock surveys matched to the CCAT Observatory. We investigate both astrophysical models of $\mathrm{[CII]}$ emission from interstellar gas and the potential for the study of primordial intermittent non-Gaussianity (PING) as a science case for Stage 2 line intensity mapping (LIM) surveys. The $\mathrm{[CII]}$ voxel intensity distribution (VID) is used as a summary statistic in forecasts. Additional constraints on PING are derived from a relative entropy study of $\mathtt{Peak~Patch}$ halo mass functions. We show that upcoming LIM surveys will provide insights into the way we model cosmological line emission, and next-generation surveys can place competitive bounds on novel inflationary scenarios such as PING. The $\mathtt{WebSky}$ $\mathrm{[CII]}$ mocks and corresponding $\mathtt{Peak~Patch}$ halo catalogues are publicly available at https://uoft.me/webskycii .