Examinando por Autor "Lin, Y."

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Acceso Abierto
The Chemical Structure of Young High-mass Star-forming Clumps. II. Parsec-scale CO Depletion and Deuterium Fraction of HCO+
(The Institute of Physics (IOP), 2020-10-01) Feng, S.; Li, D.; Caselli, P.; Du, F.; Lin, Y.; Sipilä, O.; Beuther, H.; Sanhueza, P.; Tatematsu, K.; Liu, Y.; Zhang, Q.; Wang, Y.; Hogge, T.; Jiménez Serra, I.; Lu, X.; Liu, T.; Wang, K.; Zhang, Y.; Zahorecz, S.; Li, G.; Liu, H. B.; Yuan, J.; National Natural Science Foundation of China (NSFC); Max-Planck-Gesellschaft (MPG); European Research Council (ERC); Chinese Academy of Sciences (CAS); Agencia Estatal de Investigación (AEI); Japan Society for the Promotion of Science (JSPS); Feng, S. [0000-0002-4707-8409]; Li, D. [0000-0003-3010-7661]; Caselli, P. [0000-0003-1481-7911]; Du, F. [0000-0002-7489-0179]; Lin, Y. [0000-0001-9299-5479; Sipilä, O. [0000-0002-9148-1625]; Beuther, H. [0000-0002-1700-090X]; Sanhueza, P. [0000-0002-7125-7685]; Tatematsu, K. [0000-0002-8149-8546]; Liu, S. Y. [0000-0003-4603-7119]; Zhang, Q. [0000-0003-2384-6589]; Wang, Y. [0000-0003-2226-4384]; Hogge, T. [0000-0002-7211-7078]; Jiménez Serra, I. [0000-0003-4493-8714]; Lu, X. [0000-0003-2619-9305]; Liu, T. [0000-0002-5286-2564]; Wang, K. [0000-0002-7237-3856]; Zhang, Z. Y. [0000-0002-7299-2876]; Zahorecz, S. [0000-0001-6149-1278]; Li, G. [0000-0003-3144-1952]; Liu, H. B. [0000-0003-2300-2626]; Yuan, J. [0000-0001-8060-3538]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The physical and chemical properties of cold and dense molecular clouds are key to understanding how stars form. Using the IRAM 30 m and NRO 45 m telescopes, we carried out a Multiwavelength line-Imaging survey of the 70 μm-dArk and bright clOuds (MIAO). At a linear resolution of 0.1–0.5 pc, this work presents a detailed study of parsec-scale CO depletion and HCO+ deuterium (D-) fractionation toward four sources (G11.38+0.81, G15.22–0.43, G14.49–0.13, and G34.74–0.12) included in our full sample. In each source with T < 20 K and nH ~ 104–105 cm−3, we compared pairs of neighboring 70 μm bright and dark clumps and found that (1) the H2 column density and dust temperature of each source show strong spatial anticorrelation; (2) the spatial distribution of CO isotopologue lines and dense gas tracers, such as 1–0 lines of H13CO+ and DCO+, are anticorrelated; (3) the abundance ratio between C18O and DCO+ shows a strong correlation with the source temperature; (4) both the C18O depletion factor and D-fraction of HCO+ show a robust decrease from younger clumps to more evolved clumps by a factor of more than 3; and (5) preliminary chemical modeling indicates that chemical ages of our sources are ~8 × 104 yr, which is comparable to their free-fall timescales and smaller than their contraction timescales, indicating that our sources are likely dynamically and chemically young.