2025-11-17 中国科学院（CAS）
＜関連情報＞
- https://english.cas.cn/newsroom/cas_media/202511/t20251117_1115873.shtml
- https://www.sciencedirect.com/science/article/pii/S2095927325011211
- https://academic.oup.com/nsr/advance-article/doi/10.1093/nsr/nwaf496/8322401
「膝」領域における宇宙線陽子エネルギースペクトルの精密測定 Precise measurements of the cosmic ray proton energy spectrum in the “knee” region
LHAASO Collaboration
Science Bulletin Available online: 12 November 2025
DOI:https://doi.org/10.1016/j.scib.2025.10.048
Abstract
We report the high-purity identification of cosmic-ray (CR) protons and a precise measurement of their energy spectrum from 0.15 to 12 PeV using the Large High Altitude Air Shower Observatory (LHAASO). Abundant event statistics, combined with the simultaneous detection of electrons/photons, muons, and Cherenkov light in air showers, enable spectroscopic measurements with statistical and systematic precision comparable to satellite data at lower energies. The proton spectrum shows significant hardening relative to low-energy extrapolations, culminating at 3 PeV, followed by sharp softening. This distinct spectral structure closely aligned with the knee in the all-particle spectrum points to the emergence of a new CR component at PeV energies that might be linked to the dozens of PeVatrons recently discovered by LHAASO, and offers crucial clues to the origin of Galactic cosmic rays.
ブラックホールジェット系に関連する超高エネルギーガンマ線放射 Ultrahigh-energy gamma-ray emission associated with black hole-jet systems
Zhen Cao, F Aharonian, Y X Bai, Y W Bao, D Bastieri, X J Bi, Y J Bi, W Bian, A V Bukevich, C M Cai …
National Science Review Published:16 November 2025
DOI:https://doi.org/10.1093/nsr/nwaf496
Abstract
Black holes (BH), one of the most intriguing objects in the universe, can manifest themselves through electromagnetic radiation initiated by the accretion flow. Some stellar-mass BHs drive relativistic jets when accreting matter from their companion stars, forming microquasars. Non-thermal emission from the radio to tera-electronvolt (TeV) gamma-ray band has been observed from microquasars, indicating the acceleration of relativistic particles. Here we report detection of four microquasars (SS 433, V4641 Sgr, GRS 1915+105, MAXI J1820+070) of spectrum extending to the ultrahigh-energy (UHE; photon energy E > 100 TeV) band and one microquasar (Cygnus X-1) of spectrum approaching 100 TeV, using the Large High Altitude Air Shower Observatory (LHAASO). Notably, the total emission associated with SS 433 cannot be interpreted with a single leptonic component. In the UHE band, its emission is in spatial coincidence with a giant atomic cloud, which is consistent with a hadronic origin. An elongated source is discovered from V4641 Sgr with the spectrum continuing up to 800 TeV. The detection of UHE gamma rays demonstrates that accreting BHs and their environments can operate as extremely efficient accelerators of particles out of 1 peta-electronvolt (PeV), suggesting microquasars to be important contributors to Galactic cosmic rays especially around the ‘knee’ region.
