Gravitational Interstellar Scintillation

TL;DR

Gravitational interstellar scintillation (GISS) is a predicted phenomenon where gravity from compact objects near pulsar lines-of-sight modulates pulsar signals, offering a new way to study interstellar matter and gravity effects.

Contribution

This paper introduces the concept of gravitational interstellar scintillation (GISS), highlighting its distinctive features and potential observable effects in specific astronomical contexts.

Findings

GISS has a predictable time signature and is non-dispersive.

GISS could cause observable diffraction distortions in binary pulsars.

Potential to detect GISS in compact interstellar clouds causing extreme scattering events.

Abstract

Gravitation could modulate the interstellar scintillation of pulsars in a way that is analogous to refractive interstellar scintillation (RISS). While RISS occurs when a large ionized cloud crosses the pulsar line-of-sight, gravitational interstellar scintillation (GISS) occurs when a compact gravitational deflector lies very near to that line-of-sight. However, GISS differs from RISS in at least two important respects: It has a very distinctive and highly predictible time signature, and it is non-dispersive. We find two very different astronomical contexts where GISS could cause observable diffraction-pattern distortions: Highly inclined binary pulsars, and the kind of compact interstellar clouds suspected of causing extreme scattering events.