Stellar Basins of Gravitationally Bound Particles

TL;DR

This paper introduces the concept of stellar basins, where weakly coupled particles emitted by stars accumulate over time, potentially impacting detection strategies and offering new insights into particle physics and astrophysics.

Contribution

The paper identifies a new phenomenon of volumetric stellar emission into bound orbits, leading to the formation of stellar basins that influence particle detection and astrophysical models.

Findings

Solar basin energy density surpasses relativistic flux after one million years.

New limits on axion parameters are derived independent of dark matter assumptions.

Potential for enhanced indirect detection of particles around compact stars.

Abstract

A new physical phenomenon is identified: volumetric stellar emission into gravitationally bound orbits of weakly coupled particles such as axions, moduli, hidden photons, and neutrinos. While only a tiny fraction of the instantaneous luminosity of a star (the vast majority of the emission is into relativistic modes), the continual injection of these particles into a small part of phase space causes them to accumulate over astrophysically long time scales, forming what I call a "stellar basin", in analogy with the geologic kind. The energy density of the Solar basin will surpass that of the relativistic Solar flux at Earth's location after only a million years, for any sufficiently long-lived particle produced through an emission process whose matrix elements are unsuppressed at low momentum. This observation has immediate and striking consequences for direct detection experiments---including new limits on axion parameter space independent of dark matter assumptions---and may also increase the prospects for indirect detection of weakly interacting particles around compact stars.