Testing the Radiation Pattern of Meteor Radio Afterglow

TL;DR

This study uses coordinated observations from two radio stations to analyze the radiation pattern of meteor radio afterglows, revealing that MRAs follow an isotropic emission pattern, indicating incoherent emission mechanisms.

Contribution

First simultaneous multi-station observations of MRAs and meteor scatter events, demonstrating that MRAs exhibit an isotropic radiation pattern and distinguishing their luminosity distribution.

Findings

MRAs follow an isotropic radiation pattern

Luminosity distributions differ between MRAs and meteor scatter events

Coordinated observations enable triangulation and analysis of meteor radio emissions

Abstract

Radio emission from meteors or meteor radio afterglows (MRAs) were first detected using the all-sky imaging capabilities of the first station of the Long Wavelength Array (LWA1). In this work, we use the recently commissioned LWA Sevilleta (LWA-SV) station along with the LWA1 to carry out co-ordinated observations. The combined all-sky observations with LWA1 and LWA-SV have co-observed 32 MRAs and 21 transmitter reflections from meteors (meteor scatter events) which are believed to be specular reflections from overdense trails. The flux density of the events observed by each station were measured from the all-sky images. Triangulating the angular direction of events from each station gave the physical location and the distance of the event to each station. The luminosity of the events in each station were calculated using the flux distance relation for an isotropic source. The luminosity distribution for MRAs and meteor scatter events observed by each station shows a clear distinction between these two types of events as the ratio of luminosities are closer to unity for MRAs than the meteor scatter events. Furthermore, we find that MRAs follow an isotropic radiation pattern. This suggests, either a complete incoherent emission mechanism or an incoherent addition of coherently emitting small regions within the meteor trail.