天文学进展2017，Vol.35Issue(2)：208-219,12.DOI:10.3969/j.issn.1000-8349.2017.02.04
基于LAMOST光谱新证认12个HII区
Identification of 12 H II Regions with LAMOST
摘要
Abstract
HII region is one type of emission nebula which is excited by massive stars through ultraviolet radiation. Study of H II regions provides an insight into understanding the struc-ture of the Galaxy. We newly identify 12 H II regions based on the single-exposure spectra of Galactic Anti-Center from LAMOST (Large Sky Area Multi-Object Fiber Spectroscopic Telescope) survey in this paper. Firstly, we pick out the sky and stellar spectra from LAM-OST DR3 that locate in 65 H II region candidates from Anderson et al.'s catalog of H II regions based on WISE (Wide-field Infrared Survey Explorer) data. For sky spectra and stel-lar spectra subtracting the stellar components, we calculate the line intensity ratio of both Hα/[S II] and Hα/[N II]. According to the distribution of line intensity ratio in the theoretical criteria diagram, 42 out of 65 H II region candidates are preliminarily selected. Besides, the average equivalent width of Hα and early-type stars (O or B type) harbouring in the H II region candidates are also taken into account in order to provide further constraints on the identification of H II regions. We calculate the Hαequivalent width of 7202 spectra in 65 H II region candidates, and take the average value as the equivalent width of corresponding H II region candidates. So the Hα equivalent width 6?1 is considered as one of the limitations to identify H II region. Additionally, O or B-type stars are also counted in H II region candi-dates since OB stars usually exist in H II region. We find that B-type stars are observed in 23 H II region candidates using LAMOST data. Finally, we confirm 12 out of 65 H II regions candidates are H II regions using the criteria of line intensity ratio in combination with both Hαequivalent width 6?1 and existence of O, B-type stars in the regions.关键词
HII区/LAMOST/线强比/Hα等值宽度Key words
HII region/LAMOST/line intensity ratio/Hαequivalent width分类
天文与地球科学引用本文复制引用
赵东纬,罗阿理,侯文..基于LAMOST光谱新证认12个HII区[J].天文学进展,2017,35(2):208-219,12.基金项目
国家自然科学基金(11390371) （11390371）
973 项目(2014CB845704) （2014CB845704）
