Detection of short-period pulsations in solar hard X-ray and radio emissions

Quasi-periodic pulsations (QPPs) at sub-second periods are frequently detected in the time series of X-rays and radio emissions during stellar flares, and they can be seen in solar radio emissions. However, such short-period QPPs are rarely reported in the hard X-ray (HXR) emission of solar flares. We explored the QPP patterns at short periods in HXRs, γ-ray continuum and radio emissions produced in two solar flare on 2024 October 03 (X9.0) and 2025 January 19 (C8.2). The short period at about 1 s is simultaneously observed in wavebands of HXR and γ-ray continuum during the X9.0 flare, and the restructured images show that the HXR sources move significantly during the short-period QPP, suggesting that the short-period QPP may be caused by the interaction of hot plasma loops that are rooted in double footpoints. The similar short-period QPP is also detected in wavebands of HXR and low-frequency radio emission during the impulsive phase of a C8.2 flare, which could be associated with non-thermal electrons that are periodically accelerated by the intermittent magnetic reconnection.