Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio Lobe
We report the detection of extended γ -ray emission from lobes in the radio galaxy NGC 6251 using observation data from the Fermi Large Area Telescope. The maximum likelihood analysis results show that a radio morphology template provides a better fit than a pointlike source description for the obse...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad2e07 |
| _version_ | 1797202813461200896 |
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| author | Yu-Wei Yu Hai-Ming Zhang Ying-Ying Gan Xin-Ke Hu Tan-Zheng Wu Jin Zhang |
| author_facet | Yu-Wei Yu Hai-Ming Zhang Ying-Ying Gan Xin-Ke Hu Tan-Zheng Wu Jin Zhang |
| author_sort | Yu-Wei Yu |
| collection | DOAJ |
| description | We report the detection of extended γ -ray emission from lobes in the radio galaxy NGC 6251 using observation data from the Fermi Large Area Telescope. The maximum likelihood analysis results show that a radio morphology template provides a better fit than a pointlike source description for the observational data at a confidence level of 8.1 σ , and the contribution of lobes constitutes more than 50% of the total γ -ray flux. Furthermore, the γ -ray energy spectra show a significant disparity in shape between the core and lobe regions, with a curved log-parabola shape observed in the core region and a power-law form observed in the lobes. Neither the core region nor the northwest (NW) lobe displays significant flux variations in the long-term γ -ray light curves. The broadband spectral energy distributions of the core region and the NW lobe can be explained with a single-zone leptonic model. The γ -rays of the core region are due to the synchrotron-self-Compton process, while the γ -rays from the NW lobe are interpreted as inverse Compton emission of the cosmic microwave background. |
| first_indexed | 2024-04-24T08:09:24Z |
| format | Article |
| id | doaj.art-646c8d27ad594c6fab76fd3df3b27cda |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-04-24T08:09:24Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-646c8d27ad594c6fab76fd3df3b27cda2024-04-17T08:21:31ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01965216310.3847/1538-4357/ad2e07Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio LobeYu-Wei Yu0https://orcid.org/0009-0000-6577-1488Hai-Ming Zhang1https://orcid.org/0000-0001-6863-5369Ying-Ying Gan2https://orcid.org/0000-0002-4789-7703Xin-Ke Hu3Tan-Zheng Wu4Jin Zhang5https://orcid.org/0000-0003-3554-2996School of Physics, Beijing Institute of Technology , Beijing 100081, People's Republic of China ; j.zhang@bit.edu.cnSchool of Astronomy and Space Science, Nanjing University , Nanjing 210023, People's Republic of ChinaSchool of Physics, Beijing Institute of Technology , Beijing 100081, People's Republic of China ; j.zhang@bit.edu.cnGuangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University , Nanning 530004, People's Republic of ChinaSchool of Physics, Beijing Institute of Technology , Beijing 100081, People's Republic of China ; j.zhang@bit.edu.cnSchool of Physics, Beijing Institute of Technology , Beijing 100081, People's Republic of China ; j.zhang@bit.edu.cnWe report the detection of extended γ -ray emission from lobes in the radio galaxy NGC 6251 using observation data from the Fermi Large Area Telescope. The maximum likelihood analysis results show that a radio morphology template provides a better fit than a pointlike source description for the observational data at a confidence level of 8.1 σ , and the contribution of lobes constitutes more than 50% of the total γ -ray flux. Furthermore, the γ -ray energy spectra show a significant disparity in shape between the core and lobe regions, with a curved log-parabola shape observed in the core region and a power-law form observed in the lobes. Neither the core region nor the northwest (NW) lobe displays significant flux variations in the long-term γ -ray light curves. The broadband spectral energy distributions of the core region and the NW lobe can be explained with a single-zone leptonic model. The γ -rays of the core region are due to the synchrotron-self-Compton process, while the γ -rays from the NW lobe are interpreted as inverse Compton emission of the cosmic microwave background.https://doi.org/10.3847/1538-4357/ad2e07Active galaxiesGalaxy jetsGamma-raysNon-thermal radiation sources |
| spellingShingle | Yu-Wei Yu Hai-Ming Zhang Ying-Ying Gan Xin-Ke Hu Tan-Zheng Wu Jin Zhang Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio Lobe The Astrophysical Journal Active galaxies Galaxy jets Gamma-rays Non-thermal radiation sources |
| title | Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio Lobe |
| title_full | Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio Lobe |
| title_fullStr | Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio Lobe |
| title_full_unstemmed | Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio Lobe |
| title_short | Fermi Large Area Telescope Detection of Gamma Rays from the NGC 6251 Radio Lobe |
| title_sort | fermi large area telescope detection of gamma rays from the ngc 6251 radio lobe |
| topic | Active galaxies Galaxy jets Gamma-rays Non-thermal radiation sources |
| url | https://doi.org/10.3847/1538-4357/ad2e07 |
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