High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068
High-energy neutrinos are detected by the IceCube Observatory in the direction of NGC 1068, the archetypical type II Seyfert galaxy. The neutrino flux, surprisingly, is more than an order of magnitude higher than the γ -ray upper limits at measured TeV energy, posing tight constraints on the physica...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acee70 |
| _version_ | 1797670645763407872 |
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| author | Ke Fang Enrique Lopez Rodriguez Francis Halzen John S. Gallagher |
| author_facet | Ke Fang Enrique Lopez Rodriguez Francis Halzen John S. Gallagher |
| author_sort | Ke Fang |
| collection | DOAJ |
| description | High-energy neutrinos are detected by the IceCube Observatory in the direction of NGC 1068, the archetypical type II Seyfert galaxy. The neutrino flux, surprisingly, is more than an order of magnitude higher than the γ -ray upper limits at measured TeV energy, posing tight constraints on the physical conditions of a neutrino production site. We report an analysis of the submillimeter, mid-infrared, and ultraviolet observations of the central 50 pc of NGC 1068 and suggest that the inner dusty torus and the region where the jet interacts with the surrounding interstellar medium (ISM) may be a potential neutrino production site. Based on radiation and magnetic field properties derived from observations, we calculate the electromagnetic cascade of the γ -rays accompanying the neutrinos. When injecting protons with a hard spectrum, our model may explain the observed neutrino flux above ∼10 TeV. It predicts a unique sub-TeV γ -ray component, which could be identified by a future observation. Jet–ISM interactions are commonly observed in the proximity of jets of both supermassive and stellar-mass black holes. Our results imply that such interaction regions could be γ -ray-obscured neutrino production sites, which are needed to explain the IceCube diffuse neutrino flux. |
| first_indexed | 2024-03-11T21:03:33Z |
| format | Article |
| id | doaj.art-5d18e4a6b44c48e7980721d37c852e06 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-11T21:03:33Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-5d18e4a6b44c48e7980721d37c852e062023-09-29T17:36:00ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-019561810.3847/1538-4357/acee70High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068Ke Fang0https://orcid.org/0000-0002-5387-8138Enrique Lopez Rodriguez1https://orcid.org/0000-0001-5357-6538Francis Halzen2https://orcid.org/0000-0001-6224-2417John S. Gallagher3https://orcid.org/0000-0001-8608-0408Department of Physics, Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin , Madison, WI 53706, USAKavli Institute for Particle Astrophysics and Cosmology, Stanford University , Stanford, CA 94305, USADepartment of Physics, Wisconsin IceCube Particle Astrophysics Center, University of Wisconsin , Madison, WI 53706, USADepartment of Astronomy, University of Wisconsin , Madison, WI 53706, USAHigh-energy neutrinos are detected by the IceCube Observatory in the direction of NGC 1068, the archetypical type II Seyfert galaxy. The neutrino flux, surprisingly, is more than an order of magnitude higher than the γ -ray upper limits at measured TeV energy, posing tight constraints on the physical conditions of a neutrino production site. We report an analysis of the submillimeter, mid-infrared, and ultraviolet observations of the central 50 pc of NGC 1068 and suggest that the inner dusty torus and the region where the jet interacts with the surrounding interstellar medium (ISM) may be a potential neutrino production site. Based on radiation and magnetic field properties derived from observations, we calculate the electromagnetic cascade of the γ -rays accompanying the neutrinos. When injecting protons with a hard spectrum, our model may explain the observed neutrino flux above ∼10 TeV. It predicts a unique sub-TeV γ -ray component, which could be identified by a future observation. Jet–ISM interactions are commonly observed in the proximity of jets of both supermassive and stellar-mass black holes. Our results imply that such interaction regions could be γ -ray-obscured neutrino production sites, which are needed to explain the IceCube diffuse neutrino flux.https://doi.org/10.3847/1538-4357/acee70Seyfert galaxiesRadio hot spotsHigh-energy cosmic radiationGamma-ray sources |
| spellingShingle | Ke Fang Enrique Lopez Rodriguez Francis Halzen John S. Gallagher High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068 The Astrophysical Journal Seyfert galaxies Radio hot spots High-energy cosmic radiation Gamma-ray sources |
| title | High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068 |
| title_full | High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068 |
| title_fullStr | High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068 |
| title_full_unstemmed | High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068 |
| title_short | High-energy Neutrinos from the Inner Circumnuclear Region of NGC 1068 |
| title_sort | high energy neutrinos from the inner circumnuclear region of ngc 1068 |
| topic | Seyfert galaxies Radio hot spots High-energy cosmic radiation Gamma-ray sources |
| url | https://doi.org/10.3847/1538-4357/acee70 |
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