论文标题
麦哲伦云磁盘中的弥漫性非热发射
Diffuse non-thermal emission in the disks of the Magellanic Clouds
论文作者
论文摘要
麦哲伦云是银河系的两个矮星系同伴，是费米大面积望远镜（LAT）最明亮的伽玛射线来源之一。旨在针对两种云中非热电磁和中微子发射的全面建模，我们基于最近出版的Murchison Widefield阵列和Fermi/LAT数据来自言自语地对磁盘的无线电和伽马射线光谱分布进行建模。使用精确的发射公式，请考虑所有涉及相对论和热电子（同步子，康普顿散射和Bremsstrahung）和相对论质子（与热质子相互作用后中性腐烂）的相关辐射过程。我们的联合光谱分析表明，云中的无线电发射具有原代和次级电子同步器和热bremsstrahlung的起源，而伽玛射线主要来自中性衰变，并具有相对论的bremsstrahlung和Compton散射星光，并具有相对论性的Bremsstrahlung和Compton散射。两个星系中的质子光谱在具有相似光谱指数的能量定律中建模为〜2.4和能量密度〜1 eV/cm3。预测的0.1-10 GEV中微子通量太低，无法通过当前和即将进行的实验来检测。我们的分析证实了早期关于两种麦哲伦云中伽玛射线发射的强度起源的建议。
The Magellanic Clouds, two dwarf galaxy companions to the Milky Way, are among the Fermi Large Area Telescope (LAT) brightest gamma-ray sources. Aiming at a comprehensive modeling of the non-thermal electromagnetic and neutrino emission in both Clouds, we self-consistently model the radio and gamma-ray spectral energy distribution from their disks based on recently published Murchison Widefield Array and Fermi/LAT data. All relevant radiative processes involving relativistic and thermal electrons (synchrotron, Compton scattering, and bremsstrahlung) and relativistic protons (neutral-pion decay following interaction with thermal protons) are considered, using exact emission formulae. Our joint spectral analyses indicate that radio emission in the Clouds has both primary and secondary electron synchrotron and thermal bremsstrahlung origin, whereas gamma rays originate mostly from neutral-pion decay with some contributions from relativistic bremsstrahlung and Compton scattering off starlight. The proton spectra in both galaxies are modeled as power laws in energy with similar spectral indices, ~2.4, and energy densities, ~1 eV/cm3. The predicted 0.1-10 GeV neutrino flux is too low for detection by current and upcoming experiments. Our analyses confirm earlier suggestions of a largely hadronic origin of the gamma-ray emission in both Magellanic Clouds.
