Origin of the Very High Energy γ-rays in the Low-luminosity Active Galactic Nucleus NGC 4278

Fuente: arXiv
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Autori principali: Lian, Ji-Shun, Li, Jia-Xuan, Hu, Xin-Ke, Gan, Ying-Ying, Wu, Tan-Zheng, Zhang, Hai-Ming, Zhang, Jin
Natura: Preprint
Pubblicazione: 2024
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author Lian, Ji-Shun
Li, Jia-Xuan
Hu, Xin-Ke
Gan, Ying-Ying
Wu, Tan-Zheng
Zhang, Hai-Ming
Zhang, Jin
author_facet Lian, Ji-Shun
Li, Jia-Xuan
Hu, Xin-Ke
Gan, Ying-Ying
Wu, Tan-Zheng
Zhang, Hai-Ming
Zhang, Jin
contents NGC 4278, a Low-luminosity active galactic nucleus (AGN), is generally classified as a low-ionization nuclear emission line region (LINER). Recently, it has been reported to be associated with a very high energy $γ$-ray source 1LHAASO J1219+2915 in the first Large High Altitude Air Shower Observatory source catalog. However, no associated counterpart has been detected by analyzing the data collected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. By analyzing its X-ray observation data from Swift-XRT, we find NGC 4278 is in a high-flux state on MJD 59546, with the X-ray flux more than one order of magnitude higher than that observed $\sim$ 11.7 year earlier by Chandra. Interestingly, this Swift-XRT observation was conducted during the active phase of the $γ$-ray source 1LHAASO J1219+2915. We propose that the detection of VHE $γ$-rays from NGC 4278 may be attributed to the presence of an active nucleus in its center. To reproduce the spectral energy distribution (SED) of NGC 4278, we employ a one-zone leptonic model, typically used for fitting broadband SEDs of BL Lacs, and find that a smaller magnetic field strength is required than that of typical TeV BL Lacs. Furthermore, NGC 4278 exhibits significantly lower luminosity in both radio and TeV bands when compared with typical TeV BL Lacs. In the radio-luminosity vs. Eddington-ratio plane, NGC 4278 shows greater similarity to Seyfert galaxies and LINERs rather than BL Lacs; however, it still roughly follows the extension towards lower luminosity seen in BL Lacs.
format Preprint
id arxiv_https___arxiv_org_abs_2405_00347
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Origin of the Very High Energy γ-rays in the Low-luminosity Active Galactic Nucleus NGC 4278
Lian, Ji-Shun
Li, Jia-Xuan
Hu, Xin-Ke
Gan, Ying-Ying
Wu, Tan-Zheng
Zhang, Hai-Ming
Zhang, Jin
High Energy Astrophysical Phenomena
NGC 4278, a Low-luminosity active galactic nucleus (AGN), is generally classified as a low-ionization nuclear emission line region (LINER). Recently, it has been reported to be associated with a very high energy $γ$-ray source 1LHAASO J1219+2915 in the first Large High Altitude Air Shower Observatory source catalog. However, no associated counterpart has been detected by analyzing the data collected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. By analyzing its X-ray observation data from Swift-XRT, we find NGC 4278 is in a high-flux state on MJD 59546, with the X-ray flux more than one order of magnitude higher than that observed $\sim$ 11.7 year earlier by Chandra. Interestingly, this Swift-XRT observation was conducted during the active phase of the $γ$-ray source 1LHAASO J1219+2915. We propose that the detection of VHE $γ$-rays from NGC 4278 may be attributed to the presence of an active nucleus in its center. To reproduce the spectral energy distribution (SED) of NGC 4278, we employ a one-zone leptonic model, typically used for fitting broadband SEDs of BL Lacs, and find that a smaller magnetic field strength is required than that of typical TeV BL Lacs. Furthermore, NGC 4278 exhibits significantly lower luminosity in both radio and TeV bands when compared with typical TeV BL Lacs. In the radio-luminosity vs. Eddington-ratio plane, NGC 4278 shows greater similarity to Seyfert galaxies and LINERs rather than BL Lacs; however, it still roughly follows the extension towards lower luminosity seen in BL Lacs.
title Origin of the Very High Energy γ-rays in the Low-luminosity Active Galactic Nucleus NGC 4278
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2405.00347