A catalog of early-type emission-line stars and Hα line profiles from LAMOST DR2

• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2016,（9）
• 页码范围: 39-50
• 页数: 12页
• 语种: 英文
• DOI: 10.1088/1674-4527/16/9/138

摘要

We present a catalog including 11 204 spectra of 10436 early-type emission-line stars from LAMOST DR2,among which 9752 early-type emission-line spectra are newly discovered.For these earlytype emission-line stars,we discuss the morphological and physical properties of their low-resolution spectra.In this spectral sample,the Hα emission profiles display a wide variety of shapes.Based on the Hα line profiles,these spectra are categorized into five distinct classes:single-peak emission,single-peak emission in absorption,double-peak emission,double-peak emission in absorption,and P-Cygni profiles.To better understand what causes the Hα line profiles,we divide these objects into four types from the perspective of physical classification,which include classical Be stars,Herbig Ae/Be stars,close binaries and spectra contaminated by Hn regions.The majority of Herbig Ae/Be stars and classical Be stars are identified and separated using a (H-K,K-W1) color-color diagram.We also discuss 31 binary systems that are listed in the SIMBAD on-line catalog and identify 3600 spectra contaminated by H n regions after cross-matching with positions in the Dubout-Crillon catalog.A statistical analysis of line profiles versus classifications is then conducted in order to understand the distribution of Hα profiles for each type in our sample.Finally,we also provide a table of 172 spectra with Fe Ⅱ emission lines and roughly calculate stellar wind velocities for seven spectra with P-Cygni profiles.