What Are Pulsar Companions Made of? Using Gravitational Tides to Probe Their Compositions

TL;DR

This paper explores how gravitational tides in pulsar companion systems can reveal their internal compositions by modeling tidal effects and comparing them with pulsar timing data.

Contribution

It introduces a method to constrain the internal structure of pulsar companions using tidal modeling and pulsar timing observations.

Findings

Tidal characteristics vary with different equations of state.

Model comparisons can limit the chemical composition of pulsar companions.

The approach helps understand the formation history of these objects.

Abstract

Low eccentricity, short orbital period pulsar companions may provide a probe to study novel dense and stable exoplanet internal compositions due to the potentially significant orbital evolution they experience caused by strong gravitational tides. We model the tidal characteristics such as apsidal motion constants, orbital precession, and tidal deformability for a variety of equations of state to be compared with values recovered via pulsar timing for a sample of four systems: PSR J1719-1438b, PSR J0636+5128b, PSR J2322+2650b, and PSR J1807-2459A b. With this method, we hope to place stringent limits on the chemical and structural composition of these objects. Through limiting the internal composition of pulsar companions, we aim to elucidate their unique history and formation.