Description
Spectroscopic snapshot solar imaging at radio wavelengths can yield detailed understanding of the emission processes responsible for solar radio bursts associated with massive eruptive events like flares and coronal mass ejections (CMEs). Cutting-edge radio interferometers, e.g. Murchison Widefield Array (MWA), are exceptionally well-suited for this purpose. However, spatially resolved observations of solar radio bursts from these instruments remain rather limited. Despite the availability of exquisite imaging instruments, most studies of solar radio bursts are still based on non-imaging observations using solar dedicated instruments. This is because the observing time of these versatile cutting-edge radio interferometers tends to be oversubscribed. This, coupled with the fact that solar activity is inherently unpredictable, leads to few events of interest being captured in the limited solar observing time available. Enabling observations of a large number of solar radio bursts with these new-generation instruments requires a robust and reliable automated near-real time observing trigger. Using precious observing time only when some solar activity is known to have just taken place, can vastly increase the efficiency of limited available observing time to capture solar activity. With observatories like the Square Kilometre Array Observatory (SKAO) on the horizon, the need for such a system is even more imperative. We present such a system for the SKAO-low precursor, the MWA, based on near-real time data from the YAMAGAWA spectrograph which observes the Sun daily from rise to set in the band from 70 MHz to 9 GHz and is located at similar longitude as the MWA. We have devised, implemented and tested algorithms for this automated triggering system using archival YAMAGAWA data. End-to-end tests of triggered observations have successfully been carried out at the MWA. This real time triggering has now been operationalized at the MWA, a very timely development in view of the ongoing solar maxima.
