Scientists have used simulations to show that the photons emitted by long gamma-ray bursts, the most powerful electromagnetic phenomena in the Universe, originate at the visible surface of high-speed jets emitted by exploding stars.
A team of experts in nuclear fusion and astronomy has computed high-accuracy atomic data for analyzing light from a kilonova, a birth place of heavy elements. They found that their new data set could predict kilonovae brightness with much better accuracy than before. This aids our understanding of the cosmic origins of heavy elements.
Based on computer simulations by "ATERUI" and new observations from the Atacama Large Millimeter/submillimeter Array (ALMA), researchers have found that the rings of gas surrounding active supermassive black holes are not simple donut shapes. Instead gas expelled from the center interacts with infalling gas to create a dynamic circulation pattern, similar to a water fountain in a city park. (November 30, 2018 press release)
An international research team including Takashi Moriya at DTA/NAOJ discovered the first recorded "ultra-stripped supernova," a rare, faint type of supernova that is believed to play a role in the formation of binary neutron star systems. These findings will advance our understanding of a wide variety of topics ranging from gravitational waves to the origin of precious metals like gold and platinum. This research was published in Science on October 12, 2018. (October 12, 2018 press release)
Using the powerful Japanese Subaru telescope, the Hyper Suprime-Cam (HSC) survey collaboration team has made and analyzed the deepest wide field map of the three-dimensional distribution of matter in the Universe. Led by Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Project Assistant Professor Chiaki Hikage, a team of scientists primarily from Japan, Taiwan and Princeton University has used the gravitational distortion of images of about 10 million galaxies to make a precise measurement of the lumpiness of matter in the Universe. By combining this measurement with the European Space Agency Planck satellite’s observations of the cosmic microwave background, and other cosmological experiments, the team has been able to further constrain the properties of the “dark energy” that dominates the energy density of the Universe. (September 26, 2018 press release)
At the end of its life, a red supergiant star explodes in a hydrogen-rich supernova. By comparing observation results to simulation models, an international research team including Takashi Moriya at DTA/NAOJ found that in many cases this explosion takes place inside a thick cloud of circumstellar matter shrouding the star. This result completely changes our understanding of the last stage of stellar evolution. (September 4, 2018, press release)
Based on a new study of how near-Earth asteroid Phaethon reflects light at different angles, astronomers think that its surface may reflect less light than previously thought. This is an exciting mystery for the recently approved DESTINY+ mission to investigate when it flies past Phaethon.
The supercomputer Cray XC50, nicknamed NS-05 “ATERUI II” started operation on June 1, 2018. With a theoretical peak performance of 3.087 petaflops, ATERUI II is the world’s fastest supercomputer for astrophysical simulations. ATERUI Ⅱsimulates a wide range of astronomical phenomena inaccessible to observational astronomy, allowing us to boldly go where no one has gone before, from the birth of the Universe itself to the interior of a dying star.
Astronomers have tracked down the source of a gravitational wave and discovered the first observed kilonova: a nuclear furnace 100 million times brighter than the Sun producing thousands of times the entire mass of the Earth in heavy elements such as precious metals.
