#LHAASO

[spacetimewithstuartgary]

LHAASO reveals key evidence of the cosmic ray acceleration limit in the W51 complex for the first time

The Large High Altitude Air Shower Observatory (LHAASO) officially released the precise measurements of high-energy gamma radiation from the W51 complex, confirming it as a cosmic-ray accelerator boosting particles up to so-called ultra-high energies (UHE, above 1014 electronvolts). This study also provides key evidence about the cosmic-ray acceleration limit in this complex. The findings, entitled "Evidence for particle acceleration approaching PeV energies in the W51 complex," were recently published online in Science Bulletin. The research was conducted by the LHAASO International Collaboration, led by the Institute of High Energy Physics, Chinese Academy of Sciences.

The W51 complex is one of the largest and the most active "stellar factories" in the Milky Way and one of the few regions confirmed to host GeV energy cosmic-ray accelerators. It plays a crucial role in unraveling the century-old mystery of the "origin of cosmic rays." Researchers utilized data from the LHAASO experiment to, for the first time, extend the measurements of the energy spectrum of gamma-rays from this region to the UHE range. They clearly observed a "bending" structure in the gamma-ray spectrum at tens of TeV, indicating the acceleration limit of cosmic rays in this region.  

The energy spectrum measured by LHAASO can be smoothly connected with that was measured by the Fermi-LAT collaboration at lower energies.  Spanning six orders of magnitude of gamma-ray energy. the spectrum provides important evidence that the radiation originates from collisions between cosmic rays and molecular clouds. It also indicates that the W51 complex has a cosmic-ray acceleration limit of around 400 TeV. “The supernova remnant W51C, located in the W51 complex, is the most plausible cosmic-ray accelerator responsible for the wideband gamma-ray emission”, Prof. LI Zhe said, one of the co-corresponding authors.

LHAASO is a national major science and technology infrastructure located on Haizi Mountain at an altitude of 4410 meters in Daocheng, Sichuan province, China. It consists of an array of 5216 electromagnetic particle detectors and 1188 muon detectors distributed in 1 km2, a water Cherenkov detector array covering 78,000 m2 and an array of 18 wide-field-of-view Cherenkov telescopes. LHAASO was completed and began high-quality stable operation in July 2021. It is the most sensitive UHE gamma-ray detection device in the world, characterized by the large field of view and all-weather capability.

IMAGE: The UHE gamma-ray emission is clearly observed from the W51 complex, which hosts the supernova remnant W51C and star forming region W51B. (b) The “bending” feature around tens TeV indicates the cosmic-ray acceleration limit in the W51 complex at around 400TeV. Credit ©Science China Press

[astroimages]

A MAIOR EXPLOSÃO DO UNIVERSO PODE REVELAR OS SEGREDOS DA MATÉRIA ESCURA

VISITE AGORA A MASTER CIDADANIA E FAÇA A SUA CIDADANIA ITALIANA  COM QUEM ENTENDE DO ASSUNTO, ESSE 2025 É O MOMENTO DE VOCÊ BUSCAR A SUA CIDADANIA E DESBRAVAR O MUNDO!!! VISITE O SITE E CONSULTE TODOS OS DETALHES: https://mastercidadania.com.br/ A detecção do GRB 221009A pela colaboração LHAASO marca um avanço significativo na astrofísica moderna, desafiando as teorias convencionais sobre a propagação de raios gama. Este evento foi registrado com energias de até 18 TeV z=0.151, o que indica que ocorreu a aproximadamente 1,5 bilhões de anos-luz da Terra. A importância dessa detecção reside no fato de que, segundo os modelos atuais da luz de fundo extragaláctica (EBL), fótons com energias superiores a 10 TeV deveriam ser fortemente absorvidos antes de chegarem ao nosso planeta. Os modelos EBL, como o proposto por Saldana-Lopez et al., preveem uma atenuação extrema para fótons de alta energia. Isso implica que a observação do GRB 221009A requer uma luminosidade TeV extremamente alta, o que é difícil de explicar dentro dos modelos de emissão convencionais. Assim, surge um dilema: ou o universo é mais transparente do que se acreditava ou precisamos considerar novos fenômenos físicos. A solução proposta envolve a interação entre fótons e partículas axion-like (ALPs), que são previstas por teorias além do modelo padrão, como a teoria das cordas. As ALPs são partículas muito leves e neutras que podem oscilar em fótons na presença de campos magnéticos. Essa interação não apenas aumenta a probabilidade de sobrevivência dos fótons, mas também permite que eles atravessem a EBL sem serem absorvidos. Assim, as oscilações fóton-ALP podem ocorrer em vários meios magnetizados, como na galáxia hospedeira do GRB e no espaço extragaláctico. O estudo sugere que as interações entre fótons e ALPs podem ocorrer eficientemente na galáxia hospedeira do GRB 221009A, que foi identificada como uma galáxia em disco observada lateralmente. Além disso, as oscilações também podem ocorrer na Via Láctea e no espaço extragaláctico, dependendo da intensidade do campo magnético externo. O modelo desenvolvido fornece uma explicação robusta para a detecção do GRB 221009A sem depender de suposições ad hoc frequentemente necessárias em modelos convencionais. Os resultados indicam uma forte evidência da existência das ALPs, alinhando-se com outras observações anteriores em blazares, que são núcleos galácticos ativos. A análise espectral do GRB 221009A mostra que não há um corte significativo no espectro até cerca de 20 TeV, permitindo uma extensão segura da emissão até essa energia sem desvios intrínsecos. Em conclusão, a detecção do GRB 221009A não apenas desafia as teorias existentes sobre raios gama e sua interação com o universo, mas também sugere novas direções para pesquisa sobre partículas exóticas como as ALPs. Esse evento representa um passo importante na compreensão da física fundamental e na busca por respostas sobre a natureza da matéria escura, reforçando a necessidade de revisões nas teorias atuais da astrofísica. FONTE: https://arxiv.org/abs/2412.21175 #DARKMATTER #EXPLOSION #UNIVERSE

[dailyreportonline]

Thunderstorms May Skew Ultra-High-Energy Gamma Ray Measurements, Experts Warn | Daily Reports Online

Observations of ultra–high-energy gamma rays, considered a breakthrough in cosmic studies, are raising questions regarding their accuracy due to potential interference from thunderstorms. Gamma rays exceeding one petaelectronvolt (PeV) were detected by the Large High Altitude Air Shower Observatory (LHAASO) in Tibet, hinting at cosmic accelerators far surpassing any particle collider on Earth.…

[skycrorg]

Detectan emisión de rayos gamma de muy alta energía que rodea a un púlsar distante

Los púlsares son estrellas de neutrones altamente magnetizadas y giratorias que emiten un haz de radiación electromagnética.

Utilizando el Observatorio de Lluvias de Aire a Gran Altitud (LHAASO), un equipo internacional de astrónomos ha detectado rayos gamma de muy alta energía (VHE) alrededor del púlsar PSR J0248+6021, que pueden ser el halo del púlsar o una nebulosa de viento del púlsar. El hallazgo fue reportado en un artículo publicado el 6 de octubre en el servidor de preimpresión arXiv. Los púlsares son…

[astroblogs]

[andronetalks]

Mysterious ultra-high energy source investigated by astronomers

Phys Org by Tomasz Nowakowski September 11, 2023 Astronomers from the University of Maryland and the Michigan Technological University, have inspected a mysterious ultra-high energy gamma-ray source known as LHAASO J2108+5157. Results of the study, published August 31 on the pre-print server arXiv, could help us unveil the true nature of this source. Sources emitting gamma radiation with photon…

[gaetaniu]

Gli astronomi indagano una misteriosa fonte di energia ultra potente

Mappa di significatività della regione LHAASO J2108+5157 utilizzando 2400 giorni di dati presi da HAWC. Astronomi dell’Università del Maryland e della Michigan Technological University hanno ispezionato una misteriosa sorgente di raggi gamma ad altissima energia nota come LHAASO J2108+5157. I risultati dello studio, pubblicati sul server di pre-print arXiv, potrebbero aiutarci a svelare la vera…

[adrianusv61]

Jawel: de Relativiteitstheorie is weer bewezen, dit keer voor zéér hoge energieën

Jawel: de Relativiteitstheorie is weer bewezen, dit keer voor zéér hoge energieën

Jawel, hij heeft weer eens gelijk. Credit: Pixabay/CC0 Public Domain Natuurkundigen moeten de tel kwijt zijn hoe vaak Einstein’s Relativiteitstheorie bewezen is. Onderzoekers van de Chinese Academie voor Wetenschappen hebben de zogeheten Lorentz symmetrie of invariantie bekeken bij ultrahoge energieën en daar komt uit naar voren dat ook bij die zeer hoge energieën geen verbreking van die…

[cheshirecat-rabbit]

China’s Large High Altitude Air Shower Observatory (LHAASO) aims to catch the air showers associated with the highest energy gamma rays, which in turn correspond to the highest energy cosmic rays. LHAASO is a cluster of detectors spanning more than 1 square kilometer on Haizi Mountain, 4410 meters above sea level in Sichuan province. More than 5000 detectors spread across the site capture particles associated with the highest energy strikes, while more than 1000 muon detectors, buried underground, help rule out particle showers associated with unrelated cosmic rays that constantly pepper Earth. Before LHAASO began operations in 2019, most detectors worked in much lower energy bands. But the new results show the universe is capable of far higher accelerations.

Using data from LHAASO’s first year of operation, Cao Zhen from the Institute of High Energy Physics of the Chinese Academy of Sciences and his colleagues detected more than 530 photons with energies greater than 0.1 PeV, they reported yesterday in Nature. The photons were traced to 12 cosmic ray factories capable of PeV accelerations—100 times more energetic than collisions at the world’s most powerful atom smasher, the Large Hadron Collider. The sources, which the team calls “PeVatrons,” include long-suspected accelerators, such as the Crab nebula, the site of an ancient supernova, the final explosion of a dying star, and home to a powerful pulsar, a dense neutron star. But the highest energy photons came from a surprising source: the Cygnus Cocoon, a stellar nursery 4600 light-years from the Sun. “PeVatrons are basically everywhere in our galaxy,” Cao says.

[twistarticle]

China's pursuit of cosmic rays

China’s pursuit of cosmic rays

Beijing, Oct 23 (IANS) The Chinese scientists are constructing a cosmic ray observation station on an area equivalent to 200 soccer fields in China’s southwest Sichuan Province, 4,400 meters above sea level.

Huge rocks left from the Ice Age have been blasted. Different detectors are being installed to form a huge “net” to catch the particles generated by cosmic rays in the atmosphere, to help…

[spacenutspod]

The Large High Altitude Air Shower Observatory (LHAASO) has discovered a giant ultra-high-energy gamma-ray bubble structure in the Cygnus star-forming region, which is the first time that the origin of cosmic rays with energy higher than 10 Peta-Electronvolt (PeV) has been discovered. This achievement was published in the form of a cover article in Science Bulletin on Feb. 26.

[karayoluhaber]

Karanlık Madde Bozunmasını Tespit Etmek

Karanlık Madde Bozunmasını Tespit Etmek

Yeni inşa edilen bir gama ışını gözlemevinden elde edilen ilk okumalar kullanılarak varsayımsal parçacıkların ömrüne ilişkin bir alt sınır belirlendi. Çin’in Tibet Platosu sınırındaki Sichuan Eyaleti’nde bulunan Büyük Yüksek İrtifa Hava Yağmuru Gözlemevi (LHAASO), Samanyolu ve diğer galaksilerden yayılan gama ışınlarını arıyor. Gökbilimciler bu yüksek enerjili fotonların varlığını, gama…

[skycrorg]

Astrónomos investigan una espeluznante y misteriosa fuente de energía ultra alta

Astrónomos de la Universidad de Maryland y la Universidad Tecnológica de Michigan han inspeccionado una misteriosa fuente de rayos gamma de energía ultraalta conocida como LHAASO J2108+5157. Los resultados del estudio, publicado el 31 de agosto en el servidor de preimpresión arXiv, podrían ayudarnos a revelar la verdadera naturaleza de esta fuente. Las fuentes que emiten radiación gamma con…

[astroblogs]

Jawel: de Relativiteitstheorie is weer bewezen, dit keer voor zéér hoge energieën

Jawel: de Relativiteitstheorie is weer bewezen, dit keer voor zéér hoge energieën

Jawel, hij heeft weer eens gelijk. Credit: Pixabay/CC0 Public Domain Natuurkundigen moeten de tel kwijt zijn hoe vaak Einstein’s Relativiteitstheorie bewezen is. Onderzoekers van de Chinese Academie voor Wetenschappen hebben de zogeheten Lorentz symmetrie of invariantie bekeken bij ultrahoge energieën en daar komt uit naar voren dat ook bij die zeer hoge energieën geen verbreking van die…

[arxt1]

Evidence of a thick halo for the spatial-dependent propagation model with Cosmic Ray anisotropy. (arXiv:2102.13498v2 [astro-ph.HE] UPDATED)

The spatial-dependent propagation (SDP) model with a nearby source works well to reproduce the co-evolving features of both cosmic ray (CR) nuclei spectra and anisotropy. However, it is well known that the Sun is offset from the Galactic plane. This will lead to a dominating anisotropy in perpendicular direction, which is discrepant with observations. Thus it is necessary to reboot further investigation into the effect of the solar offset. In this work, for the first time the combined studies of the solar offset, nuclei spectra and anisotropy are performed based on the SDP model. As a result, to reproduce CR spectra and anisotropy, the thickness of the halo $\rm (\xi z_h)$ increases linearly with the displacement of the Sun. When the offset is $\rm \sim8~pc$ as estimated from the matter-borne methods, $\rm \xi z_h$ is about 0.9 kpc, which is a much thicker halo than usually. Moreover, the PeV anisotropy could estimate the value of diffusion coefficient, thus breaking the degeneracy of diffusion coefficient and halo thickness. Therefore it is a good messenger to constrain the halo thickness. On the other hand, the anisotropy in PeV energy region, as a new probe, might also shed new light to constrain the solar offset. We hope that the anisotropy at the energies of $\rm \sim TeV$ to $\rm PeV$ can be finely measured by LHAASO experiment, leading to a better understanding about the thick halo.

from astro-ph.HE updates on arXiv.org https://ift.tt/ZI83qXN