$^{18}$O$/^{17}$O abundance ratio toward a sample of massive star forming regions with parallax distances

Autor: Ou, Chao, Wang, Junzhi, Zheng, Siqi, Li, Juan, Romano, Donatella, Zhang, Zhi-Yu
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1093/mnras/stad1004
Popis: The $^{18}$O$/^{17}$O abundance ratio is, in principle, a powerful tool to estimate the relative contributions of massive stars and low- to intermediate-mass stars to the chemical enrichment of galaxies. We present $^{18}$O$/^{17}$O ratios derived from simultaneous observations of C$^{18}$O and C$^{17}$O 1-0 toward fifty-one massive star forming regions with the Institut de Radioastronomie Millim\'etrique (IRAM) 30 meter telescope. Simultaneous observations of HC$^{18}$O$^{+}$ 1-0 and HC$^{17}$O$^{+}$ 1-0 with the Yebes 40m telescope toward five sources from this sample were also done to test the consistency of $^{18}$O$/^{17}$O ratios derived from different isotopic pairs. From our improved measurements, resulting in smaller errors than previous work in the literature, we obtain a clear trend of increasing $^{18}$O$/^{17}$O ratio with increasing galactocentric distance (D$_{GC}$), which provides a significant constraint on Galactic chemical evolution (GCE) models. Current GCE models have to be improved in order to explain the observed C$^{18}$O/C$^{17}$O 1-0 gradient.
Comment: 15 pages, 5 figures, 1 table, Accepted for publication in MNRAS
Databáze: arXiv