Abstract
AbstractMorphological and chemical structures of M33 are investigated with the LAMOST DR7 survey. Physical parameters; extinction; chemical composition of He, N, O, Ne, S, Cl, and Ar (where available); and radial velocities were determined for 110 nebulae (95 Hiiregions and 15 planetary nebulae) in M33. Among them, 8 planetary nebulae and 55 Hiiregions in M33 are newly discovered. We obtained the following O abundance gradients: −0.199−0.030+0.030dexR25−1(based on 95 Hiiregions), −0.124−0.036+0.036dexR25−1(based on 93 Hiiregions), and −0.207−0.174+0.160dexR25−1(based on 21 Hiiregions), utilizing abundances from N2 at O3N2 diagnostics and theTe-sensitive method, respectively. The He, N, Ne, S, and Ar gradients resulted in slopes of −0.179−0.146+0.145, −0.431−0.281+0.282, −0.171−0.239+0.234, −0.417−0.182+0.174, and −0.340−0.157+0.156, respectively, utilizing abundances from theTe-sensitive method. Our results confirm the existence of the negative axisymmetric global metallicity distribution that is assumed in the literature. We noticed one new WC star candidate and one transition W-R WN/C candidate. The grand-design pattern of the spiral structure of M33 is presented.
Funder
National Natural Science Foundation of China
MOST ∣ National Key Research and Development Program of China
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics
Cited by
5 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献