Mini-Workshop on High-energy Cosmic Explosions

9:15-9:30 opening remark

Speaker: Prof. Brian P. Schmidt (The Australian National University)

Prof. Brian P. Schmidt is a Distinguished Astrophysicist and Nobel Laureate, renowned for his pioneering contributions to observational cosmology. He was awarded the 2011 Nobel Prize in Physics for the discovery of the accelerating expansion of the Universe through observations of distant Type Ia supernovae, providing the first direct evidence for dark energy.

Prof. Schmidt is a Professor at the Australian National University (ANU) and has played a leading role in large international astronomical surveys. His research interests include supernova cosmology, dark energy, and the large-scale structure of the Universe. He has also been deeply involved in scientific leadership and the advancement of astronomy at both national and international levels.

09:30-09:50 Fast Radio Bursts and the BURSTT Project

Speaker: Prof. Tetsuya Hashimoto (National Chung Hsing University)

Abstract: The Hubble constant (H₀) describes the expansion rate of the Universe. Determining its value is a central goal in modern astronomy. However, recent studies have revealed a persistent tension between different measurements of H₀, called the Hubble tension. Therefore, a new and independent method to constrain H₀ is essential to address the Hubble tension. Fast radio bursts (FRBs) are mysterious, millisecond-duration coherent radio pulses, most of which originate in galaxies at cosmological distances. One of the key observables of FRBs is the dispersion measure (DM), the integral of the free-electron density along the line of sight. The intergalactic component of the DM (DM_IGM) is proportional to H₀. Therefore, FRB DMs may offer a new and independent way to constrain H₀ for addressing the Hubble tension. In this talk, I will present a new methodology to constrain H₀ by using the temporal scattering of FRB pulses. Our approach can reduce the systematic uncertainty in FRB-based H₀ measurements by approximately 9%. This level of systematics is comparable to the current Hubble tension, suggesting that our method could play a significant role in resolving the discrepancy with future FRB samples. If time permits, I will also introduce BURSTT, a new radio telescope in Taiwan dedicated to FRB observations.

09:50-10:10 From High-z Supernovae to Fast Transients: Taiwan’s Growing Role in the Time-Domain Universe

Speaker: Prof. Ting-Wan Chen (National Central University)

Abstract: The breakthroughs from high-redshift supernova cosmology reshaped modern astronomy and motivated today’s wide-field transient surveys. As the field shifts from discovery to rapid follow-up, Taiwan has developed an important role through flexible and responsive small telescopes. At Lulin Observatory, the 40-cm SLT and 1-m LOT, working with collaborations such as ePESSTO+, ZTF, ENGRAVE, and Kinder, provide high-cadence, multi-colour observations of supernovae, gamma-ray bursts, and fast X-ray transients. This talk will highlight key results, including observations of SN 2024ggi—the nearest core-collapse supernova in the past decade, optical follow-up of the first-year Einstein Probe fast X-ray transients, and confirmation of SN 2025wny (SN Winny), the first lensed superluminous supernova. These cases show how small telescopes complement large surveys and strengthen Taiwan’s role in the global time-domain network as we enter the LSST era.

10:50-11:10 Gravitational Wave Astrophysics in Taiwan

Speaker: Prof. Albert Kong (National Tsing Hua University)

Abstract: The first direct detection of gravitational waves (GWs) in 2015, followed by the groundbreaking joint observation of GW170817 (a binary neutron star merger) and its electromagnetic counterpart, launched the era of multi-messenger astronomy (MMA). The global detector network has since expanded, and its operational, data analysis, and scientific efforts are poised for formal unification in 2026 under the International Gravitational-Wave Observatory Network (IGWN). This unification represents a critical step toward maximizing the discovery potential of next-generation detectors. Taiwanese scientists and observational facilities are critically positioned to contribute to the MMA component of the IGWN. In the last few years, Taiwan has demonstrated significant capabilities through rapid optical follow-up and GW data analysis of burst signals. In this talk, I will briefly review some of the contributions of Taiwan in IGWN.

11:10-11:30 Bootstrapping Forefront Science with Small Telescopes

Speaker: Prof. Wen-Ping Chen (National Central University)

Abstract: In an era of large to gigantic OIR telescopes, small telescopes can still carry out niche science, particularly in global networking or on focused topics.  Here I describe how NCU with limited human and financial resources operates a suite of small telescopes at Lulin  Observatory, the largest being a humble one meter, to study cosmic temporal phenomena, such as stellar variability, or transient objects, by joining high-profile international collaborations or making use of more powerful facilities to "secure the discoveries". I will reminisce about the projects I have been heavily involved with the lessons well learned.