NEUTRINO AND COSMIC-RAY EMISSION AND CUMULATIVE BACKGROUND FROM RADIATIVELY INEFFICIENT ACCRETION FLOWS IN LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI
NEUTRINO AND COSMIC-RAY EMISSION AND CUMULATIVE BACKGROUND FROM RADIATIVELY INEFFICIENT ACCRETION FLOWS IN LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI
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DOI：
10.1088/0004-637x/806/2/159
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发表时间：
2014-11
期刊：
影响因子：
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通讯作者：
S. Kimura;K. Murase;K. Toma
中科院分区：
文献类型：
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作者：
S. Kimura;K. Murase;K. Toma
我们研究了低光度活动星系核（LLAGN）核心的高能中微子和宇宙射线（CR）发射。在LLAGN中，粒子的热化预计在辐射低效吸积流（RIAF）中是不完全的，允许非热粒子的存在。在这项工作中，假设riaf中由于湍流引起的随机粒子加速，我们求解了Fokker-Planck方程并计算了逃逸中微子和cr的光谱。LLAGN中的RIAF可以发射出质量为> 10 ？通过pp和/或p γ ？产生的> PeV能量和TeV-PeV中微子>反应。我们发现，如果吸积光度的~ 1%被非热离子带走，来自LLAGN核心的弥散中微子强度可能高达e2 Φ ~ 3 × 10−8 GeV cm−2 s−1 sr−1 ？>，可以与观测到的冰立方数据兼容。这个结果与费米观测到的漫射伽马射线背景或观测到的漫射CR通量都不矛盾。我们的模型表明，尽管高能伽马射线可能不会逃逸，但具有riaf的无线电安静活动星系核可以发射GeV伽马射线，这可以用于测试模型。我们还计算了LLAGN的riaf的中子光度，并讨论了散射中微子观测中中子介导的射流质量加载模型的强约束。
We study high-energy neutrino and cosmic-ray (CR) emission from the cores of low-luminosity active galactic nuclei (LLAGN). In LLAGN, the thermalization of particles is expected to be incomplete in radiatively inefficient accretion flows (RIAF), allowing the existence of non-thermal particles. In this work, assuming stochastic particle acceleration due to turbulence in RIAFs, we solve the Fokker–Planck equation and calculate spectra of escaping neutrinos and CRs. The RIAF in LLAGN can emit CR protons with ≳ 10 ?> PeV energies and TeV–PeV neutrinos generated via pp and/or p γ ?> reactions. We find that, if ∼1% of the accretion luminosity is carried away by non-thermal ions, the diffuse neutrino intensity from the cores of LLAGN may be as high as E 2 Φ ∼ 3 × 10 − 8 GeV cm − 2 s − 1 sr − 1 ?> , which can be compatible with the observed IceCube data. This result does not contradict either of the diffuse gamma-ray background observed by Fermi or observed diffuse CR flux. Our model suggests that, although very-high-energy gamma-rays may not escape, radio-quiet active galactic nuclei with RIAFs can emit GeV gamma-rays, which could be used for testing the model. We also calculate the neutron luminosity from RIAFs of LLAGN, and discuss a strong constraint on the model of jet mass loading mediated by neutrons from the diffuse neutrino observation.