RIKEN Nishina Center for Accelerator-Based Science Cosmic Radiation Laboratory

Director: Toru Tamagawa (D.Sc.)

Japanese Page

Research Summary

Immediately after the Big Bang, the beginning of our universe, only hydrogen and helium existed. However, nucleosynthesis in the supernova explosions over the course of 13.8 billion years led to the evolution of a world brimming with the many different elements we have today. By using satellites to detect X-rays and gamma-rays, we are observing the synthesized elements at their actual source. Our goal is to comprehensively elucidate the scenarios for the formation of the elements in the universe. We are also conducting observations of the extreme conditions near black holes and neutron stars that are unreachable on Earth, to see how far our knowledge of physics can be applied.

Main Research Fields

Mathematical & Physical Sciences

Related Research Fields

Engineering
Interdisciplinary Science & Engineering
Particle-, nuclear-, astro-physics, and related fields
Astronomy and related fields
Plasma science and related fields

Keywords

Nucleosynthesis in the Universe
Physics in Extreme Conditions
Development of Innovative Radiation Detectors
Promotion of Space Utilization with Small Satellites
Space Applications of Fundamental Science

Selected Publications

1. Marin, F., et al.:
"X-ray polarization evidence for a 200 years-old flare of Sgr A*"
Nature 619, 41-45 (2023).
2. Takeda, T., et al:
"Gas selection for Xe-based LCP-GEM detectors onboard the CubeSat X-ray observatory NinjaSat"
Journal of Instrumentation 18, C06020 (2023).
3. Xie, F., et al.:
"Vela pulsar wind nebula X-rays are polarized to near the synchrotron limit"
Nature 612, 658-660 (2022).
4. Taverna, R., et al.:
"Polarized x-rays from a magnetar"
Science 378, 646-650 (2022).
5. Krawczynski, H., et al.:
"Polarized x-rays constrain the disk-jet geometry in the black hole x-ray binary Cygnus X-1"
Science 378, 650-654 (2022).
6. Baldini, L., et al.:
"Design, construction, and test of the Gas Pixel Detectors for the IXPE mission"
Astroparticle Physics 133, 102628 (2021).
7. Nakahira, S.; et al.:
"MAXI/SSC All-sky maps from 0.7 keV to 4 keV"
Publications of the Astronomical Society of Japan 72, 17 (2020).
8. Tamagawa, T., et al.:
"Multiplexing lobster-eye optics: a concept for wide-field x-ray monitoring"
Journal of Astronomical Telescopes, Instruments, and Systems 6, 025003 (2020).
9. Gu, L., et al.:
"Observations of a Pre-Merger Shock in Colliding Clusters of Galaxies"
Nature Astronomy 3, 838 (2019).
10. Kitaguchi, T., et al.:
"A convolutional neural network approach for reconstructing polarization information of photoelectric X-ray polarimeters"
Nuclear Inst. and Methods in Physics Research A 942, 162389 (2019).