At energies ~>2 keV, active galactic nuclei (AGN) are the source of the cosmic X-ray background (CXB). For AGN population synthesis models to replicate the peak region of the CXB (~30 keV), a highly obscured and therefore nearly invisible class of AGN, known as Compton thick (CT) AGN, must be assumed to contribute nearly a third of the CXB. In order to constrain the CT fraction of AGN and the CT number density we consider several hard X-ray AGN luminosity functions and the contribution of blazars to the CXB. Following the unified scheme, the radio AGN luminosity function is relativistically beamed to create a radio blazar luminosity function. An average blazar spectral energy density model is created to transform radio luminosity to X-ray luminosity. We find the blazar contribution to the CXB to be 12% in the 0.5-2 keV band, 7.4% in the 2-10 keV band, 8.9% in the 15-55 keV band, and 100% in the MeV region. When blazars are included in CXB synthesis models, CT AGN are predicted to be roughly one-third of obscured AGN, in contrast to the prediction of one half if blazars are not considered. Our model implies a BL Lac X-ray duty cycle of ~13%, consistent with the concept of intermittent jet activity in low power radio galaxies.
Implications on the blazar sequence and inverse Compton models from Fermi bright blazars
In this paper, we use the quasi-simultaneous spectra of Fermi bright blazars and Fermi detected narrow line Seyfert 1 (NLS1) to study the blazar sequence and inverse Compton (IC) models. I. The synchrotron peak luminosities ( L_{s} ) significantly inverse correlate with the synchrotron peak frequencies (ν_{s}), L_{s} \propto ν_{s}^{-0.44}, which is consistent with the blazar sequence. In addition to the correlation, there are some blazars showing low ν_{s} and low L_{s} . To study the relation between these low ν_{s} low L_{s} blazars and the blazar sequence, we present correlations of the par…
The Cosmological Impact of Luminous TeV Blazars I: Implications of Plasma Instabilities for the Intergalactic Magnetic Field and Extragalactic Gamma-Ray Background
Current and Future Constraints on Dark Matter from Prompt and Inverse-Compton Photon Emission in the Isotropic Diffuse Gamma-ray Background
我们进行了详细的检查，从提示和逆康普顿发射光子，包括模型相关和模型无关的边界的湮灭和衰变暗物质模型的电流约束。我们还表明，所观察到的各向同性弥散伽马射线背景（DGRB），这提供了一个最保守的约束模型的湮灭弱尺度暗物质粒子，可能会提高其灵敏度的一个因素~2至3（95% C. L.）。因为费米-LAT实验通过五年的观测解决了DGRB贡献的blazar源。对于我们的预测，我们采用的结果约束的光度依赖的密度演化加上blazar光谱能量分布序列模型，这是由DGRB和blazar源计数分布函数的约束。
Implications of Plasma Beam Instabilities for the Statistics of the Fermi Hard Gamma-ray Blazars and the Origin of the Extragalactic Gamma-Ray Background
