oLIMpus: An Effective Model for Line Intensity Mapping Auto- and Cross- Power Spectra in Cosmic Dawn and Reionization

TL;DR

oLIMpus is a fast, analytical model for simulating and analyzing line-intensity mapping auto- and cross-power spectra across multiple spectral lines during cosmic dawn and reionization, aiding parameter inference.

Contribution

It extends an existing 21-cm effective model to include multiple emission lines and improves modeling of shot noise and redshift-space distortions, enabling efficient multi-line analysis.

Findings

Provides a computationally efficient tool for LIM power spectra analysis.

Includes prescriptions for various emission lines like OII, OIII, Hα, Hβ, CII, CO.

Supports mock coeval boxes and lightcones for comprehensive studies.

Abstract

Line-intensity mapping (LIM) is emerging as a powerful probe of the high-redshift Universe, with a growing number of LIM experiments targeting various spectral lines deep into the epochs of reionization and cosmic dawn. A key remaining challenge is the consistent and efficient modeling of the diverse emission lines and of the observables of different surveys. Here, we present oLIMpus, a fully analytical effective model to study LIM auto- and cross- power spectra. Our work builds on the 21-cm effective model presented in Zeus21, applying it to star-forming lines and improving it in different aspects. Our code accounts for shot noise and linear redshift-space distortions and it includes by default prescriptions for OII, OIII, H$\alpha$, H$\beta$, CII, CO line luminosities, together with the 21-cm model inherited from Zeus21. Beyond auto- and cross-power spectra, oLIMpus can produce mock coeval boxes and lightcones, and with a computational time of $\sim s$ it is ideal for parameter-space exploration and inference. Its modular implementation makes it easy to customize and extend, enabling various applications, such as MCMC analyses and consistent multi-line cross-correlations.