Detecting unresolved moving sources in a diffuse background

TL;DR

This paper introduces a statistical method that extends the 2-point correlation function to include temporal data, enabling detection of moving sources within diffuse backgrounds across various astrophysical contexts.

Contribution

The authors develop a formalism for the spacetime 2-point function, allowing for the identification of moving sources in diffuse backgrounds, tested through simulations and applicable to multiple astrophysical phenomena.

Findings

Robust detection of moving sources in simulated sky maps

Effective identification of stationary sources as well

Applicable to gamma-ray, neutrino, and lensing data

Abstract

We present a statistical technique which can be used to detect the presence and properties of moving sources contributing to a diffuse background. The method is a generalization of the 2-point correlation function to include temporal as well as spatial information. We develop a formalism which allows for a derivation of the spacetime 2-point function in terms of the properties of the contributing sources. We test this technique in simulated sky maps, and demonstrate its robustness in identifying the presence of moving and stationary sources. Applications of this formalism to the diffuse gamma-ray background include searches for solar system bodies, fast moving primordial black holes, and dense cores of dark matter proto-halos in the solar neighborhood. Other applications include detecting the contribution of energetic neutrinos originating in the solar system, as well as probing compact objects in long timeline lensing experiments.