HyperFlash Ultra-high-cadence observations of fast radio burst sources

Fast radio bursts (FRBs) are among the most mysterious phenomena in modern astrophysics. These extremely energetic radio bursts originate from extragalactic distances. Despite major progress in recent years, many questions remain about their origins, emission processes, and local environments. Thousands of FRBs have been detected, but only a small fraction have been observed to repeat, the so-called repeating FRBs, or repeaters.
To address these questions, we established the HyperFlash program, a coordinated, high-cadence monitoring effort using 25-32 m-class radio telescopes across Europe at Westerbork (NL), Toruń (PL), Onsala (SE), Stockert (DE), and Dwingeloo (NL). Our goal is to detect the brightest and rarest FRBs. Over the past five years, HyperFlash has accumulated more than 42,000 hours of observing time.
Across burst samples from four repeating FRB sources, we find that highly energetic bursts occur more frequently than previously assumed, at a rate remarkably similar to that of apparently non-repeating FRBs. This suggests a possible link between the two populations, indicating that they may be powered by the same underlying physical mechanism. By detecting some of the most energetic bursts ever observed from repeaters, we further push the known limits of FRB energetics and find that both populations can reach similar maximum energies, providing an important constraint on theoretical models. By measuring bursts from the same sources over many months, we also find that their local environments can change significantly over time, providing new clues about the dynamic environments in which FRBs are produced.
In this thesis, we show that even relatively small radio telescopes, when used strategically and in coordination, can make a scientific impact.