Pulsar Timing Signatures of Circumbinary Asteroid Belts

TL;DR

This paper explores how asteroid belts around pulsars influence timing signals, especially in binary systems, and discusses their implications for gravitational-wave detection, highlighting differences from other noise sources.

Contribution

It analyzes the effects of circumbinary asteroid belts on pulsar timing signals and their impact on gravitational-wave searches, considering binary system dynamics.

Findings

Asteroid belts induce low-frequency, correlated noise in pulsar timing.

Binary companions destabilize short-period asteroid orbits, affecting the signal.

Asteroid belt noise can mimic gravitational-wave background but is distinguishable by lack of correlation between pulsars.

Abstract

The gravitational pull of a large number of asteroids perturbs a pulsar's motion to a degree that is detectable through precision timing of millisecond pulsars. The result is a low-frequency, correlated noise process, similar in form to the red timing noise known to affect canonical pulsars, or to the signal expected from a stochastic gravitational-wave background. Motivated by the observed fact that many millisecond pulsars are in binary systems, we describe the ways in which the presence of a binary companion to the pulsar would affect the signal produced by an asteroid belt. The primary effect of the companion is to destabilize the shortest-period orbits, cutting off the high-frequency component of the signal from the asteroid belt. We also discuss the implications of asteroid belts for gravitational-wave search efforts. Compared to the signal from a stochastic gravitational-wave background, asteroid belt noise has a similar frequency and amplitude, and is similarly independent of radio frequency, but is not correlated between different pulsars, which should allow the two kinds of signal to be distinguished.