Galactic diffuse gamma-ray flux at the energy about 175 TeV

Anisotropies in the diffuse gamma-ray background measured by the Fermi-LAT

The contribution of unresolved sources to the diffuse gamma-ray background could produce anisotropies in this emission on small angular scales. Recent studies have considered the angular power spectrum and other anisotropy metrics as tools for identifying contributions to diffuse emission from unresolved source classes, such as extragalactic and Galactic dark matter as well as various astrophysical gamma-ray source populations. We present preliminary results of an anisotropy analysis of the diffuse emission measured by the Fermi-LAT.

The Steady-State Multi-TeV Diffuse Gamma-Ray Emission Predicted with GALPROP and Prospects for the Cherenkov Telescope Array

Cosmic Rays (CRs) interact with the diffuse gas, radiation, and magnetic fields in the interstellar medium (ISM) to produce electromagnetic emissions that are a significant component of the all-sky flux across a broad wavelength range. The Fermi Large Area Telescope (LAT) has measured these emissions at GeV $γ$-ray energies with high statistics. Meanwhile, the High-Energy Stereoscopic System (H.E.S.S.) telescope array has observed large-scale Galactic diffuse emission in the TeV $γ$-ray energy range. The emissions observed at GeV and TeV energies are connected by the common origin of the CR pa…

高能伽马射线来自低亮度活动星系核NGC 4278：对弥漫中微子背景的启示

TeV Gamma-Rays from the Low-Luminosity Active Galactic Nucleus NGC 4278: Implications for the Diffuse Neutrino Background

研究NGC 4278高能伽马射线的起源，通过AGN喷流和风两种情景分析，探讨其在不同状态下的发射机制，并提出未来观测可区分喷流与喷流-Hadronic模型，同时解释弥漫中微子背景。

Diffuse gamma-ray emission from the Galactic center and implications of its past activities

It has been indicated that low-luminosity active galactic nuclei (LLAGNs) are accelerating high-energy cosmic-ray (CR) protons in their radiatively inefficient accretion flows (RIAFs). If this is the case, Sagittarius A* (Sgr A*) should also be generating CR protons, because Sgr A* is a LLAGN. Based on this scenario, we calculate a production rate of CR protons in Sgr A* and their diffusion in the central molecular zone (CMZ) around Sgr A*. The CR protons diffusing in the CMZ create gamma-rays through pp interaction. We show that the gamma-ray luminosity and spectrum are consistent with observ…

Diffuse Galactic Gamma Rays from Shock-Accelerated Cosmic Rays

A shock-accelerated particle flux \propto p^-s, where p is the particle momentum, follows from simple theoretical considerations of cosmic-ray acceleration at nonrelativistic shocks followed by rigidity-dependent escape into the Galactic halo. A flux of shock-accelerated cosmic-ray protons with s ~ 2.8 provides an adequate fit to the Fermi-LAT gamma-ray emission spectra of high-latitude and molecular cloud gas when uncertainties in nuclear production models are considered. A break in the spectrum of cosmic-ray protons claimed by Neronov, Semikoz, & Taylor (PRL, 108, 051105, 2012) when fitting …

来自TeV晕的超高能伽马射线弥漫发射

Diffuse Ultra-High-Energy Gamma-Ray Emission From TeV Halos

本研究指出LHAASO观测到的10 TeV至1 PeV银河平面弥漫伽马射线超出与银河系脉冲星周围的TeV晕预测一致，证明TeV晕主导超高能天空并将约5%的自转能转化为高能光子。