Revisit of GeV Gamma-Ray Emission from Orion B with the Fermi Large Area Telescope  

作　　者：Wei Zeng Xiao-Na Sun Rui-Zhi Yang Jia-Chun He Zhao-Dong Shi Ting-Ting Ge Yun-Feng Liang En-Wei Liang 

机构地区：[1]Guangxi Key Laboratory for Relativistic Astrophysics,School of Physics Science and Technology,Guangxi University,Nanning 530004,China [2]Department of Astronomy,School of Physical Sciences,University of Science and Technology of China,Hefei 230026,China [3]CAS Key Labrotory for Research in Galaxies and Cosmology,University of Science and Technology of China,Hefei 230026,China [4]School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026,China [5]School of Physics and Astronomy,Sun Yat-sen University,Zhuhai 519082,China

出　　处：《Research in Astronomy and Astrophysics》2024年第9期128-135,共8页天文和天体物理学研究（英文版）

基　　金：supported by National Key R&D Program of China(grant No.2023YFE0117200);the National Natural Science Foundation of China(NSFC,grant Nos.12133003,12103011);R-Z.Y.is supported by the NSFC under grants 11421303,12041305;Science and Technology Program of Guangxi(grant Nos.AD 21220075 and 2024GXNSFBA010375);the national youth thousand talents program in China。

摘　　要：We revisit the γ-ray emission above 300 Me V towards the massive star-forming region of Orion B by adopting14 yr observations with the Fermi Large Area Telescope and utilizing the updated software tools.The extended γ-ray emission region around Orion B is resolved into two components(region Ⅰ and region Ⅱ).The γ-ray spectrum of region I agrees with the predicted γ-ray spectrum assuming the cosmic ray(CR)density is the same as that of Alpha Magnetic Spectrometer(AMS-02)measured locally.Theγ-ray emissivity of region II appears to be deficit at low energy band(E<3 GeV).Through modeling we find that CR densities exhibit a significant deficit below 20 Ge V,which may be caused by a slow diffusion inside the dense region.This is probably caused by an increased magnetic field whose strength increases with the gas density.

关 键 词：(ISM:)cosmic rays gamma-rays:ISM (Galaxy:)open clusters and associations:individual(NGC 2023 NGC 2024 NGC 2068 and NGC 2071) 

分 类 号：P111[天文地球—天文学] P172.3