The low cosmic-ray density in the Polaris Flare  

作　　者：Zhi-Wei Cui Rui-Zhi Yang Bing Liu 崔志伟;杨睿智;刘冰(CAS Key Laboratory for Research in Galaxies and Cosmology,Department of Astronomy,School of Physical Sciences,University of Science and Technology of China,Hefei 230026,China;School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026,China;Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University),Ministry of Education,Nanjing 210093,China)

机构地区：[1]CAS Key Laboratory for Research in Galaxies and Cosmology,Department of Astronomy,School of Physical Sciences,University of Science and Technology of China,Hefei 230026,China [2]School of Astronomy and Space Science,University of Science and Technology of China,Hefei 230026,China [3]Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University),Ministry of Education,Nanjing 210093,China

出　　处：《Research in Astronomy and Astrophysics》2021年第10期46-50,共5页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Foundation of China(NSFC Grant No.11421303);the national youth thousand talents program in China;supported by the Fundamental Research Funds for the Central Universities。

摘　　要：We reported theγ-ray observation towards the giant molecular cloud Polaris Flare.Together with the dust column density map,we derived the cosmic ray(CR)density and spectrum in this cloud.Compared with the CR measured locally,the CR density in the Polaris Flare is significantly lower and the spectrum is softer.Such a different CR spectrum reveals either a rather large gradient of CR distribution in the direction perpendicular to the Galactic plane or a suppression of CR inside molecular clouds.

关 键 词：cosmic rays gamma rays:ISM ISM:clouds 

分 类 号：P172.4[天文地球—天文学]