IceCube has observed an excess of neutrino events over expectations from the isotropic background from the direction of NGC 1068. The excess is inconsistent with background expectations at the level of $2.9σ$ after accounting for statistical trials. Even though the excess is not statistical significant yet, it is interesting to entertain the possibility that it corresponds to a real signal. Assuming a single power-law spectrum, the IceCube Collaboration has reported a best-fit flux $ϕ_ν\sim 3 \times 10^{-8} (E_ν/{\rm TeV})^{-3.2}~({\rm GeV \, cm^2 \, s})^{-1}$, where $E_ν$ is the neutrino energy. Taking account of new physics and astronomy developments we give a revised high-energy neutrino flux for the Stecker-Done-Salamon-Sommers AGN core model and show that it can accommodate IceCube observations.
Seyfert galaxy targets for KM3NeT neutrino telescope
Université Paris Cité（巴黎西岱大学）；CNRS（法国国家科学研究中心）；Astroparticule et Cosmologie（粒子物理与宇宙学）；Laboratory of Astrophysics, École Polytechnique Fédérale de Lausanne（洛桑联邦理工学院天体物理学实验室）；Bogolyubov Institute for Theoretical Physics of the NAS of Ukraine（乌克兰国家科学院博戈留博夫理论物理研究所）；Kyiv Academic University（基辅学术大学）
Very high energy (VHE) emission has been detected from the radio galaxy NGC1275, establishing it as a potential cosmic-ray (CR) accelerator and a high energy neutrino source. We here study neutrino and $γ$-ray emission from the core of NGC1275 simulating the interactions of CRs assumed to be accelerated by magnetic reconnection, with the accreting plasma environment. To do this, we combine (i) numerical general relativistic (GR) magneto-hydrodynamics (MHD), (ii) Monte Carlo GR leptonic radiative transfer and, (iii) Monte Carlo interaction of CRs. A leptonic emission model that reproduces the S…
NGC 1068, a nearby type-2 Seyfert galaxy, is reported as the hottest neutrino spot in the 10-year survey data of IceCube. Although there are several different possibilities for the generation of high-energy neutrinos in astrophysical sources, feasible scenarios allowing such emission in NGC 1068 have not yet been firmly defined. We show that the flux level of GeV and neutrino emission observed from NGC 1068 implies that the neutrino emission can be produced only in the vicinity of the supermassive black hole in the center of the galaxy. The coronal parameters, such as magnetic field strength a…
The galaxies M82, NGC 253, NGC 1068, and NGC 4945 have been detected in gamma-rays by Fermi. Previously, we developed and tested a model for cosmic ray interactions in the starburst galaxy M82. Now, we aim to explore the differences between starburst and active galactic nuclei (AGN) environments by applying our self-consistent model to the starburst galaxy NGC 253 and the Seyfert galaxy NGC 1068. Assuming constant cosmic-ray acceleration efficiency by supernova remnants with Milky-Way parameters, we calculate the cosmic-ray proton and primary and secondary electron/positron populations, predic…
The detection of high-energy astrophysical neutrinos and ultra-high-energy cosmic rays (UHECRs) provides a new way to explore sources of cosmic rays. One of the highest energy neutrino events detected by IceCube, tagged as IC35, is close to the UHECR anisotropy region detected by Pierre Auger Observatory. The nearby starburst galaxy (SBG), NGC 4945, is close to this anisotropic region and inside the mean angular error of the IC35 event. Considering the hypernovae contribution located in the SB region of NGC 4945, which can accelerate protons up to $\sim 10^{17} \, {\rm eV}$ and inject them int…
The nearby active galaxy NGC 1275, has widely been detected from radio to gamma rays. Its spectral energy distribution (SED) shows a double-peak feature, which is well explained by synchrotron self-Compton (SSC) model. However, recent TeV detections might suggest that very-high-energy $γ$-rays (E$\geq$100 GeV) may not have a leptonic origin. We test a lepto-hadronic model to describe the whole SED through SSC emission and neutral pion decay resulting from p$γ$ interactions. Also, we estimate the neutrino events expected in a Km$^3$ Cherenkov telescope.
High-Energy Neutrino Emission in NGC1068 driven by Turbulent Magnetic Reconnection
Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG-USP), Universidade de São Paulo（圣保罗大学地球物理与大气科学学院）；Centro Brasileiro de Pesquisas Físicas (CBPF)（巴西物理研究中心）
Multi-wavelength observations indicate that some starburst galaxies show a dominant non-thermal contribution from their central region. These active galactic nuclei (AGN)-starburst composites are of special interest, as both phenomena on their own are potential sources of highly-energetic cosmic rays and associated gamma-ray and neutrino emission. In this work, a homogeneous, steady-state two-zone multi-messenger model of the non-thermal emission from the AGN corona as well as the circumnuclear starburst region is developed and subsequently applied to the case of NGC 1068, which has recently s…
Recent multi-wavelength observations indicate that some starburst galaxies show a dominant nonthermal contribution from its central region. These active galactic nuclei (AGN)-starburst composites are of special interest, as both phenomena on their own are potential sources of the high-energetic cosmic rays and their accompanied gamma-ray and neutrino emission. Here, we will focus on NGC 1068, which is known since several years from its atypical radio-gamma-ray correlation. Recently this source has also shown strong indications of high energy neutrino emission. A first semi-analytical, two-comp…
Interpreting Swift and NuSTAR Observations of the Low-Luminosity Active Galactic Nucleus NGC 4278 with Radiatively Inefficient Accretion Flows and Implications for Neutrino Emission
The Pennsylvania State University（宾夕法尼亚州立大学）；University of Utah（犹他大学）；Tohoku University（东北大学）
A Turbulence-Driven Magnetic Reconnection Model for the High-Energy Neutrino Emission from NGC 1068
Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG), Universidade de São Paulo（圣保罗大学天文、地球物理与大气科学研究所）；Centro Brasileiro de Pesquisas Físicas（巴西物理研究中心）
Neutrinos and gamma rays from Seyfert galaxies constrain the properties of coronal turbulence
Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）；Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Napoli（意大利国家核物理研究所，那不勒斯分部）；Department of Physics, Columbia University（哥伦比亚大学物理系）；Department of Astronomy, Columbia University（哥伦比亚大学天文学系）；INAF - Astrophysical Observatory of Arcetri（意大利国家天体物理研究所阿切特里天文台）；Université Paris Cité, CNRS, Astroparticule et Cosmologie（巴黎西岱大学，法国国家科学研究中心，粒子天体物理学实验室）；National and Kapodistrian University of Athens（雅典国立卡波季斯特里安大学）；Institute of Accelerating Systems & Applications（加速系统与研究所）；Center for Computational Astrophysics, Flatiron Institute（西蒙斯基金会平顿研究所计算天体物理中心）
Constraining the contribution of Seyfert galaxies to the diffuse neutrino flux in light of point source observations
Max Planck Institute for Physics（马克斯·普朗克物理研究所）；TUM School of Natural Sciences, Technical University of Munich（慕尼黑工业大学自然科学院）；Institutt for fysikk, Norwegian University of Science and Technology（挪威科技大学物理系）；Max Planck Institute for Extraterrestrial Physics（马克斯·普朗克地外物理学研究所）
Physical origin of very-high-energy gamma rays from the low-luminosity active galactic nucleus NGC 4278 and implications for neutrino observations
Guangxi University（广西大学）；The Pennsylvania State University（宾夕法尼亚州立大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；TIANFU Cosmic Ray Research Center（天府宇宙线研究中心）；Tohoku University（东北大学）
Multimessenger Constraints on Production Sites of High-Energy Neutrinos from NGC 1068
The Pennsylvania State University（宾夕法尼亚州立大学）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）
Turbulent AGN coronae as the origin of diffuse neutrinos up to PeV energies
School of Astronomy and Space Science, Nanjing University（南京大学天文与空间科学学院）；Key laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education（现代天文学和天体物理学教育部重点实验室（南京大学））；Tianfu Cosmic Ray Research Center（天府宇宙线研究中心）
Diagnosing the AGN population origin of TeV neutrinos with their spatial correlation
School of Astronomy and Space Science, Nanjing University（南京大学天文与空间科学学院）；Key laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education（现代天文学和天体物理学教育部重点实验室（南京大学））；Tianfu Cosmic Ray Research Center（天府宇宙线研究中心）
