English
日本語Supernovae
Supernovae are explosions of stars at the end of their lives. Core-collapse supernovae (Type II, Ib, and Ic) are the outcome of the gravitational collapse of massive stars (i.e., more than ten times as massive as the Sun), followed by formation of a neutron star or a black hole, announced by a huge amount of neutrinos. Thermonuclear supernovae (Type Ia) are explosions driven by nuclear reactions within a white-dwarf star.
Supernovae provide natural laboratories for a range of physical processes, such as neutrino physics, some of which can not be addressed by experiments on the Earth. Furthermore, they are the main contributors of heavy elements in the Universe; without them, baryons in the Universe would be only hydrogen, helium and some minor elements, although in reality the Universe is filled with about a hundred different sorts of elements. Their energy produced at the explosions is huge, and supernova explosions could play important roles even in formation and evolution of galaxies. Finally, importance of understanding their natures is highlighted by their use as cosmological distance indicators, leading to the discovery of the Dark Energy.
Our understanding of the above issues is still far from satisfying, with various issues still under investigation. At IPMU, we cover most of the topics related to supernovae; Evolution of stars toward supernovae (K. Nomoto), theory of core-collapse and explosion (K. Sato), theory of neutrinos from supernovae (K. Sato) and attempt to detect these neutrinos at Kamioka (M. Vagins), theory of thermonuclear explosion (K. Nomoto), nucleosynthesis of elements up to iron (K. Maeda) and beyond (S. Wanajo), formation of dust grains (T. Nozawa), theory of optical emission from supernovae and evaluation of their use as cosmological distance indicators (K. Nomoto, K. Maeda), and observations using the Subaru telescope (K. Maeda). By unifying these attempts, we aim to comprehensively understand supernovae and their influences on the evolution of the Universe.
Group Members
Alexander Kusenko
Pulsar kicks, supernova neutrinos, supernova asymmetries.
Keiichi Maeda
Theory of nucleosynthesis and radiation transfer. Observations of individual supernovae.
Search for supernova neutrinos using Super-Kamiokande detector. It covers both supernova burst neutrinos and supernova relic neutrinos.
Type Ia supernova cosmology to provide precision constraints on cosmic acceleration and the equation of state of dark energy by clarifying the progenitors and explosion mechanism. Evolution and nucleosynthesis of first stars to study cosmic chemical evolution. Gamma-ray bursts and hypernovae to clarify the production mechanisms of huge explosion energy from black holes and neutron stars.
Takaya Nozawa
Evolution of dust at high redshifts, considering the formation of dust in supernovae and destruction of dust in the shock driven by supernovae.
Super-Kamiokande and T2K for studying neutrino physics, supernova, and proton decay.
Yoichiro Suzuki
Development of future multi-megaton detectors which can detect neutrino bursts from supernovae every year.
Yasuo Takeuchi
Real-time neutrino burst search in Super-Kamiokande.
Masaomi Tanaka
Observations of core-collapse and Type Ia supernovae especially with optical spectroscopy and spectropolarimetry. Numerical simulations of radiative transfer.
Shinya Wanajo
Origin of elements that are synthesized in supernovae. Nucleosynthesis of r-process species (e.g., gold, platinum, uranium, etc.) in core-collapse supernovae.
Mark Vagins
Detection of the diffuse neutrino background produced by distant supernovae. Improvement of Super-Kamiokande experiment's response to the arrival of a burst of neutrinos from a supernova within our galaxy.
Naoki Yoshida
Theory of evolution of very massive stars and core-collapse supernovae. Supernova light-curves and hunting for high redshift supernovae using groud-based and space telescopes.