Optical Extinctions of Inter-Arm Molecular Clouds in M31:A Pilot Study for the Upcoming CSST Observations  

作　　者：Cailing Chen Zheng Zheng Chao-Wei Tsai Sihan Jiao Jing Tang Jingwen Wu Di Li Yun Zheng Linjing Feng Yujiao Yang Yuan Liang 

机构地区：[1]National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory of Radio Astronomy and Technology,Chinese Academy of Sciences,Beijing 100101,China [4]Institute for Frontiers in Astronomy and Astrophysics,Beijing Normal University,Beijing 102206,China [5]Zhejiang Lab,Hangzhou 311121,China

出　　处：《Research in Astronomy and Astrophysics》2024年第6期323-333,共11页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China Nos.11988101,12373012,and 12041302;supported by CMS-CSST-2021A08 and CMS-CSST-2021-B02;support from NSFC with grant No.12203064。

摘　　要：Recent submillimeter dust thermal emission observations have unveiled a significant number of inter-arm massive molecular clouds in M31.However,the effectiveness of this technique is limited to its sensitivity,making it challenging to study more distant galaxies.This study introduces an alternative approach,utilizing optical extinctions derived from space-based telescopes,with a focus on the forthcoming China Space Station Telescope(CSST).We first demonstrate the capability of this method by constructing dust extinction maps for 17 inter-arm massive molecular clouds in M31 using the Panchromatic Hubble Andromeda Treasury data.Our analysis reveals that inter-arm massive molecular clouds with an optical extinction(A_(V)) greater than 1.6 mag exhibit a notable A_(V) excess,facilitating their identification.The majority of these inter-arm massive molecular clouds show an A_(V) around 1 mag,aligning with measurements from our JCMT data.Further validation using a mock CSST RGB star catalog confirms the method's effectiveness.We show that the derived A_(V)values using CSST z and y photometries align more closely with the input values.Molecular clouds with A_(V)> 1.6 mag can also be identified using the CSST mock data.We thus claim that future CSST observation clouds provide an effective way for the detection of inter-arm massive molecular clouds with significant optical extinction in nearby galaxies.

关 键 词：infrared:stars ISM:clouds Galaxy:structure 

分 类 号：P15[天文地球—天文学]