Speaker
Description
The detectors of the Pierre Auger Observatory, primarily designed to observe ultra-high energy cosmic rays and identify their sources, simultaneously take advantage of their sensitivity and large coverage area to detect transient luminous events and terrestrial gamma-ray flashes (TGFs), atmospheric phenomena closely linked to lightning and thunderstorms. Owing to their sensitivity to high-energy photons, the 1600 water-Cherenkov detectors recently revealed a unique characteristic of downward TGFs. However, the TGF production mechanism is not well understood and requires further observations of lightning processes in their earliest stages. To meet this challenge, the Broadband Observatory of Lightning and TGFs (BOLT) is a detector set up to image lightning propagation in three dimensions with high temporal resolution using radio interferometry. With eleven modified Auger Engineering Radio Array (AERA) stations and their bandwidth ranging from 30 – 80 MHz, the necessary spatial and temporal resolution can be provided.
This contribution presents recent hardware developments, including progress toward selective triggering and precision timing, and the first field data recorded with BOLT, which have been analyzed using the knowledge gained from previous AERA measurements. Together with the existing detector systems of the Pierre Auger Observatory, BOLT establishes a powerful experimental framework for advancing our understanding of lightning physics and associated high-energy atmospheric phenomena.
$^*$Supported by BMBF Verbundforschung Astroteilchenphysik (Vorhaben 05A23PX1)
