Testing the Radiation Pattern of Meteor Radio Afterglow

摘要

Radio emission from meteors or meteor radio afterglows (MRAs) was first detected using the all-sky imaging capabilities of the first station of the LongWavelength Array (LWA1). In this work, we use the recently commissioned LWA Sevilleta (LWA-SV) station along with the LWA1 to carry out coordinated observations. The combined all-sky observations with LWA1 and LWA-SV have coobserved 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 was 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 was 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 is 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.