天文学进展2021，Vol.39Issue(1)：82-93,12.DOI:10.3969/j.issn.1000-8349.2021.01.05
蝎虎天体能谱曲率与其伽马射线辐射亮度的关系
The Curvature of Spectral Energy Distribution and γ-ray Dominance of Fermi BL Lac Objects
摘要
Abstract
The extragalactic γ-ray sky is dominated by blazars and their study plays an important role in understanding jet physics,cosmic evolution history and origin of ultra high energy cosmic rays.In this work,we study a large sample of BL Lac objects to investigate why some sources are detected in γ-rays,while others not.We selected 170 BL Lac objects,with measured synchrotron spectral curvature and Doppler factor,and divided them into Fermi-LAT detected (FBLs) and non-detected (NFBLs) sources.We show that FBLs have smaller curvature than NFBLs,even after getting rid of Doppler beaming effect.The BL Lac objects PKS 0048-09 and S5 0716+714 have similar synchrotron peak frequency and luminosity but different γ-ray dominance and their quasi-simultaneous broadband spectral energy distributions (SEDs) can be well fitted by a log-parabolic synchrotron self-Compton (SSC) model with same jet parameters except for the curvature and source size,assuming curvature being proportional to the size of emission region.Our results imply that for a given synchrotron luminosity,the different SED curvature and Compton dominance may account for the discrepancy between FBLs and NFBLs.We discuss these results in context of stochastic particle acceleration and radiation mechanisms.关键词
活动星系核/BL Lac天体/辐射机制/非热辐射Key words
active galactic nuclei/BL Lac Objects/non-thermal radiation/radiation mechanisms分类
天文与地球科学引用本文复制引用
Muhammad Shahzad Anjum,陈亮,顾敏峰..蝎虎天体能谱曲率与其伽马射线辐射亮度的关系[J].天文学进展,2021,39(1):82-93,12.基金项目
国家自然科学基金(U1831138,11873073) （U1831138,11873073）
