Molecular line emissions are commonly used to trace the distribution and properties of molecular Interstella Medium.However,the emissions are heavily blended on the Galactic disk toward the inner Galaxy because of th ...Molecular line emissions are commonly used to trace the distribution and properties of molecular Interstella Medium.However,the emissions are heavily blended on the Galactic disk toward the inner Galaxy because of th relatively large line widths and the velocity overlaps of spiral arms.Structure identification methods based on voxe connectivity in Position-Position-Velocity(PPV)data cubes often produce unrealistically large structures,which i the“over-linking”problem.Therefore,identifying molecular cloud structures in these directions is not trivial.W propose a new method based on Gaussian decomposition and graph theory to solve the over-linking problem named InterStellar Medium Gaussian Component Clustering(ISMGCC).Using the Milky Way Imaging Scrol Painting(MWISP)^(13)CO(1-0)data in the range of 13°.5≤l≤14°.5,|b|≤0°.5,and-100≤V_(lsr)≤+200 km s^(-1),our method identified three hundred molecular gas structures with at least 16 pixels.These structures contain 92%of the total flux in the raw data cube and show single-peaked line profiles on more than 93%of their pixels.Th ISMGCC method could distinguish gas structures in crowded regions and retain most of the flux without globa data clipping or assumptions on the structure geometry,meanwhile,allowing multiple Gaussian components fo complicated line profiles.展开更多
基金sponsored by the National Key R&D Program of China under grants 2023YFA1608000,2017YFA0402701the CAS Key Research Program of Frontier Sciences under grant QYZDJ-SSW-SLH047+1 种基金supported by the National Natural Science Foundation of China(NSFC,grant Nos.U2031202,12373030,and 11873093)the Natural Science Foundation of Jiangsu Province(grant No.BK20231509)。
文摘Molecular line emissions are commonly used to trace the distribution and properties of molecular Interstella Medium.However,the emissions are heavily blended on the Galactic disk toward the inner Galaxy because of th relatively large line widths and the velocity overlaps of spiral arms.Structure identification methods based on voxe connectivity in Position-Position-Velocity(PPV)data cubes often produce unrealistically large structures,which i the“over-linking”problem.Therefore,identifying molecular cloud structures in these directions is not trivial.W propose a new method based on Gaussian decomposition and graph theory to solve the over-linking problem named InterStellar Medium Gaussian Component Clustering(ISMGCC).Using the Milky Way Imaging Scrol Painting(MWISP)^(13)CO(1-0)data in the range of 13°.5≤l≤14°.5,|b|≤0°.5,and-100≤V_(lsr)≤+200 km s^(-1),our method identified three hundred molecular gas structures with at least 16 pixels.These structures contain 92%of the total flux in the raw data cube and show single-peaked line profiles on more than 93%of their pixels.Th ISMGCC method could distinguish gas structures in crowded regions and retain most of the flux without globa data clipping or assumptions on the structure geometry,meanwhile,allowing multiple Gaussian components fo complicated line profiles.
