Very High-energy Gamma-Ray Episodic Activity of Radio Galaxy NGC 1275 in 2022–2023 Measured with MACE
| Autor: | S. Godambe, N. Mankuzhiyil, C. Borwankar, B. Ghosal, A. Tolamatti, M. Pal, P. Chandra, M. Khurana, P. Pandey, Z. A. Dar, S. Godiyal, J. Hariharan, Keshav Anand, S. Norlha, D. Sarkar, R. Thubstan, K. Venugopal, A. Pathania, S. Kotwal, Raj Kumar, N. Bhatt, K. Chanchalani, M. Das, K. K. Singh, K. K. Gour, M. Kothari, Nandan Kumar, Naveen Kumar, P. Marandi, C. P. Kushwaha, M. K. Koul, P. Dorjey, N. Dorji, V. R. Chitnis, R. C. Rannot, S. Bhattacharyya, N. Chouhan, V. K. Dhar, M. Sharma, K. K. Yadav |
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| Jazyk: | angličtina |
| Rok vydání: | 2024 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal Letters, Vol 974, Iss 2, p L31 (2024) |
| Druh dokumentu: | article |
| ISSN: | 2041-8213 2041-8205 |
| DOI: | 10.3847/2041-8213/ad8083 |
| Popis: | The radio galaxy NGC 1275, located at the central region of Perseus cluster, is a well-known very high-energy (VHE) gamma-ray emitter. The Major Atmospheric Cherenkov Experiment Telescope has detected two distinct episodes of VHE ( E > 80 GeV) gamma-ray emission from NGC 1275 during 2022 December and 2023 January. The second outburst, observed on 2023 January 10, was the more intense of the two, with flux reaching 58% of the Crab Nebula flux above 80 GeV. The differential energy spectrum measured between 80 GeV and $1.5\,\dot{{\rm{T}}}{\rm{eV}}$ can be described by a power law with a spectral index of Γ = −2.90 ± 0.16 _stat for both flaring events. The broadband spectral energy distribution derived from these flares, along with quasisimultaneous low-energy counterparts, suggests that the observed gamma-ray emission can be explained using a homogeneous single-zone synchrotron self-Compton model. The physical parameters derived from this model for both flaring states are similar. The intermediate state observed between two flaring episodes is explained by a lower Doppler factor or magnetic field, which subsequently returned to its previous value during the high-activity state observed on 2023 January 10. |
| Databáze: | Directory of Open Access Journals |
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