Insights from probability distribution functions of intensity maps

Abstract

In the next few years, intensity-mapping surveys that target lines such as CO, Ly$\alpha$, and CII stand to provide powerful probes of high-redshift astrophysics. However, these line emissions are highly non-Gaussian, and so the typical power-spectrum methods used to study these maps will leave out a significant amount of information. We propose a new statistic, the probability distribution of voxel intensities, which can access this extra information. Using a model of a CO intensity map at $z\sim 3$ as an example, we demonstrate that this voxel intensity distribution (VID) provides substantial constraining power beyond what is obtainable from the power spectrum alone. We find that a future survey similar to the planned COMAP Full experiment could constrain the CO luminosity function to order $\sim 10\%$. We also explore the effects of contamination from continuum emission, interloper lines, and gravitational lensing on our constraints and find that the VID statistic retains significant constraining power even in pessimistic scenarios.

14 pages, 13 figures, submitted to MNRAS

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Cited by in corpus (4)

• Strategies to Detect Dark-Matter Decays with Line-Intensity Mapping
• Studying high-z galaxies with [CII] intensity mapping
• Exploration of 3D wavelet scattering transform coefficients for line-intensity mapping measurements
• Cross-correlations between mm-wave line-intensity mapping and weak lensing surveys: preliminary consideration of long-term prospects