{"id":298481,"date":"2021-07-13T19:50:01","date_gmt":"2021-07-13T16:50:01","guid":{"rendered":"https:\/\/en.buradabiliyorum.com\/astronomers-detect-ultra-high-energy-gamma-ray-source\/"},"modified":"2021-07-13T19:50:01","modified_gmt":"2021-07-13T16:50:01","slug":"astronomers-detect-ultra-high-energy-gamma-ray-source","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/astronomers-detect-ultra-high-energy-gamma-ray-source\/","title":{"rendered":"#Astronomers detect ultra-high energy gamma-ray source"},"content":{"rendered":"

“#Astronomers detect ultra-high energy gamma-ray source<\/strong>”<\/p>\n

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\"Astronomers
\n The significance map of LHAASO J0341+5258 above 25 TeV. The green circle marks the position of 4FGL J0340.4+5302, and the blue cross marks the position of the pulsar PSR J0343+5312. Credit: Cao et al., 2021.
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Astronomers from the Chinese Academy of Science<\/a>s (CAS) and elsewhere report the detection of a new ultra-high energy (UHE) gamma-ray source in the Galactic plane. The newly identified source, designated LHAASO J0341+5258, is extended and emission from it reaches up to 200 TeV. The finding is detailed in a paper published July 5 on arXiv.org.<\/p>\n


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Sources emitting gamma radiation with photon energies between 100 GeV and 100 TeV are called very-high energy (VHE) gamma-ray sources, while those with photon energies above 0.1 PeV are known as ultra-high energy (UHE) gamma-ray sources. The nature of these sources is still not well understood; therefore, astronomers are constantly searching for new objects of this type to characterize them, which could shed more light on their properties in general<\/a>.<\/p>\n

Now, a team of astronomers led by Zhen Cao of CAS has found a new source of this type using China’s Large High Altitude Air Shower Observatory (LHAASO). LHAASO J0341+5258 was detected during an obervational campaign between December 2019 and November 2020.<\/p>\n

“Since December 2019, the half of LHAASO-KM2A experiment has monitored the sky in the declination band from -15 degrees to 75 degrees above tens of TeV with high duty cycle. An excess with a pre-trial significance of 8.2\u03c3 was detected from the direction of LHAASO J0341+5258 using events with energy above 25 TeV,” the researchers wrote in the paper.<\/p>\n

The observations found that LHAASO J0341+5258 is an extended source with angular size of app<\/a>roximately 0.29 degrees. The gamma-ray emission from this source reaches values of nearly 200 TeV (0.2 PeV).<\/p>\n

The results show that the integrated energy flux of gamma-ray emissions for LHAASO J0341+5258 above 25 TeV accounts for about 20 percent of the flux from the Crab Nebula. The astronomers added that energy spectrum of this source can be described by a power-law, even though there is a hint of curvature at around 50 TeV.<\/p>\n

Furthermore, it was found that LHAASO J0341+5258 is positionally coincident with a known GeV gamma-ray source 4FGL J0340.4+5302. Therefore, the researchers assume that both sources may have a unified origin.<\/p>\n

Summing up the results, the authors of the paper noted that LHAASO J0341+5258 could be an extended emission of a pulsar wind nebula (PWN) and\/or a pulsar halo. However, the challenge of this scenario is the lack of a reported powerful pulsar.<\/p>\n

“Interestingly, such a pulsar could be the gamma-ray source 4FGL J0340.4+5302 with a characteristic spectrum below 1 GeV. The detection of pulsed radio emission from this source would support the IC [inverse Compton] origin of the UHE gamma-ray emission,” the scientists explained.<\/p>\n

They added that hadronic origin of the UHE emission from LHAASO J0341+5258 can be interpreted as an ‘echo’ from molecular clouds. This is the result of interactions of protons with dense gas regions in the proximity of an old supernova remnant.<\/p>\n\n

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New ultra-high energy gamma-ray source detected\n <\/p><\/div>\n

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\n More information:<\/strong>
\n Discovery of a new \u03b3-ray source LHAASO J0341+5258 with emission up to 200TeV, arXiv:2107.02020 [astro-ph.HE] arxiv.org\/abs\/2107.02020<\/a><\/p><\/div>\n

\n \u00a9 2021 Science X Network<\/p>\n

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Citation<\/strong>:
\n Astronomers detect ultra-high energy gamma-ray source (2021, July 13)
\n retrieved 14 July 2021
\n from https:\/\/phys.org\/news<\/a>\/2021-07-astronomers-ultra-high-energy-gamma-ray-source.html<\/p>\n

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\n part may be reproduced without the written permission. The content is provided for information purposes only.<\/p><\/div>\n<\/p><\/div>\n