China’s observatory unravels key thriller of cosmic ray formation-Xinhua

BEIJING, Nov. 17 (Xinhua) — Scientists utilizing China’s Large High Altitude Air Shower Observatory (LHAASO) discovered that black holes, devouring materials from their companion stars and producing jets, act as highly effective particle accelerators and should play a key position within the manufacturing of high-energy cosmic rays within the Milky Way.

“The studies not only uncover the key mechanisms behind cosmic ray origins but also advance our understanding of the extreme physical processes of black hole systems,” mentioned Cao Zhen, principal investigator of LHAASO and an academician of the Chinese Academy of Sciences (CAS).

Cosmic rays are charged particles from outer house, primarily composed of protons. The origin of cosmic rays is among the most necessary frontier points in fashionable astrophysics.

Measurements of cosmic rays over the previous a long time have revealed a turning level round 3 PeV (peta-electron volt) within the vitality spectrum, known as the “knee” as a result of its form resembles a knee joint. The origin of cosmic rays within the “knee” area is among the most intriguing subjects in cosmic ray analysis in recent times.

The LHAASO analysis group discovered that microquasars pushed by accretion onto black gap techniques are highly effective particle accelerators within the Milky Way and are seemingly the sources of the “knee.”

The analysis, performed by researchers from the Institute of High Energy Physics of the CAS, Nanjing University, the University of Science and Technology of China, La Sapienza University of Rome, and different establishments, was revealed in National Science Review and Science Bulletin on Sunday.

Black holes, among the many most enigmatic objects within the universe, generate relativistic jets after they accrete materials from companion stars in binary techniques, forming “microquasars,” the scientists defined.

In this research, LHAASO systematically detected ultra-high-energy gamma rays from 5 microquasars.

For occasion, evaluation of the microquasar SS 433 confirmed that the proton vitality on this system exceeds 1 PeV, with an influence output per second equal to the vitality launched by 400 trillion of essentially the most highly effective hydrogen bombs.

The gamma-ray vitality from the microquasar V4641 Sgr reached 0.8 PeV, indicating that the guardian particles producing these gamma rays seemingly had energies exceeding 10 PeV.

These outcomes show that microquasars are vital PeV particle accelerators within the Milky Way, Cao mentioned.

To absolutely perceive the “knee” of the cosmic-ray spectrum, exact measurements of the vitality spectra of varied cosmic ray species, together with their respective “knees,” are important, Cao mentioned.

Located on a mountain at an elevation of about 4,410 meters above sea degree in southwest China’s Sichuan Province, and overlaying an space of 1.36 sq. km, LHAASO is used for cosmic ray remark and analysis.

Leveraging its world-leading ground-based cosmic-ray remark tools, LHAASO developed multi-parameter measurement strategies. The measurement revealed an vitality spectrum construction that was solely sudden.

The new discovery not solely marks a big development in resolving the long-standing thriller of the “knee” origin, which has puzzled the educational group for practically 70 years, but in addition affords essential observational proof for understanding the position of black holes because the origin of cosmic rays, Cao mentioned.

LHAASO, which was designed, constructed, and is operated by Chinese scientists, has taken the lead in high-energy cosmic-ray researches because of its sensitivity in each gamma ray astronomical exploration and cosmic ray precision measurements. It has achieved a collection of discoveries which have a world influence, thereby contributing to the understanding of the acute bodily processes within the universe, Cao added.  ■