Early-type emission-line stars in LAMOST survey Hou Wen whou@bao.ac.cn LAMOST, NAOC 2017.02.19 我报告的主要内容是利用LAMOST数据对早发射做的的一些工作，并对之后将要研究的内容进行介绍，请各位老师 1

Outline Introduction Early-type emission-line stars in LAMOST DR2 Future work

Introduction Early-type emission-line stars Spectroscopy: Hydrogen emission, sometimes accompanied by matellic lines (O,Fe,Ca etc.) 首先简要介绍早型发射线恒星的研究背景，这类恒星涵盖了广泛的恒星演化阶段，从主序前恒星到行星状星云阶段，在光谱上普遍表现出H的发射特征。

Introduction Early-type emission-line stars Photometry: infrared excess in different degree 它的测光特性是会呈现不同程度的红外超现象

Introduction Early-type emission-line stars Emission lines & infrared excess- the evolutionary state of circumstellar disk 这些特性的产生最终归因于其星周物质的几何位置，物理构成以及演化状态，因此它们也是研究星周盘或者星周包层活动性的重要场所。

Early-type emission-line stars in LAMOST DR2(Done) H line profiles Physical classification Analysis of subsamples LAMOST DR4 The sample of emission-line stars (Done) Physical classification: Herbig Ae/Be, classical Ae/Be … distribution and evolutionary scenario in color-color diagram the circumstellar disks of different type 到目前为止我们所做的工作主要是对DR2和DR4光谱数据的研究，接下来的工作内容主要围绕两方面的问题，一是利用双色图上的分布对其演化状态的分析，另一个是对不同发射线恒星其星周盘物理特性，形成结构以及演化阶段的分析

Early-type emission-line stars in LAMOST DR2  200,000 OBA stars in DR2 11,204 early-type emission-line stars，among which 9,752 objects are new discovered Detection of H emission line in the spectra of LAMOST DR2 Sample selection five types of H line profiles Morphological classification of H line profiles Classical Ae/Be Herbig Ae/Be Close binaries Stars in HII regions Physical classification of the sample Fe emission lines P-Cygni profile Analysis of subsamples 首先简单介绍第一部分已完成的工作

Early-type emission-line stars in LAMOST DR2 Initial sample – about 200,000 spectra of O, B or A type stars classified by 1D pipeline Early-type emission-line stars H detection for two cases 11,204 spectra with H emission profile

Early-type emission-line stars in LAMOST DR2 Morphological classification of line profiles – geometry of circumstellar disks 星周盘的几何位置，转轴倾角密切相关

Early-type emission-line stars in LAMOST DR2 Spectra contaminated by HII regions Cross-match with the catalogue of HII regions from Dubout-Crillon (1976) 3,600 spectra contaminated by HII regions Close binaries archived by SIMBAD 19 Eclipsing binaries mainly Algol-type stars 12 cataclysmic variable stars (2 dwarf nova, 3 nova and 2 nova-like stars) CBe stars and HAeBe stars (H-K) vs (K-W1) color-color diagram 5,594 CBe and 23 HAeBe stars 以及对早型发射线恒星样本的物理分类

Early-type emission-line stars in LAMOST DR2 The separation of CBe stars and HAeBe stars (H-K, K-L) two-color criteria proposed by Finkenzeller & Mundt (1984) CBe stars: H-K < 0.2 and K-L < 0.5 HAeBe stars: H-K > 0.4 and K-L > 0.8 The magnitudes of H and K from 2MASS and UKIDSS L band is replaced by W1 from WISE Interstellar extinction correction 对Cbe和HAeBe的区分利用了双色判据在恒星分类上的应用

Early-type emission-line stars in LAMOST DR2 The separation of CBe stars and HAeBe stars (H-K, K-L) two-color criteria proposed by Finkenzeller & Mundt (1984) CBe stars: H-K < 0.2 and K-L < 0.5 HAeBe stars: H-K > 0.4 and K-L > 0.8 The magnitudes of H and K from 2MASS and UKIDSS L band is replaced by W1 from WISE Interstellar extinction correction 双色判据在恒星分类上的应用

Early-type emission-line stars in LAMOST DR2 Morphological analysis of H profiles for different groups

Early-type emission-line stars in LAMOST DR2 Variability of H profiles

Early-type emission-line stars in LAMOST DR2 Analysis of subsamples Fe emission lines P-cygni profiles 初步研究

Early-type emission-line stars in LAMOST DR4  310,000 OBA stars in DR4(snr>10) Detection of H emission line – machine learning Train and Test samples: 7000 early-type emission-line stars in DR2 SVML, SVMNL, ANNs and Softmax 以上是对DR2中早型发射线恒星的研究工作。而对在DR4这类恒星的搜寻，既然有了DR2中这10000个已知样本，我们利用这个数据集作为训练和测试样本，利用四种机器学习的方法对早型发射线恒星进行搜索，左右各20A

Early-type emission-line stars in LAMOST DR4 性能指标，准确率，完备率以及精确率，1.分对的的发射与分对的非发射 2.分对的发射占应该（真实）分对的比例 3. 分对的发射占（分对的发射+分错的发射） 都相当高

Early-type emission-line stars in LAMOST DR4  310,000 OBA stars in DR4(snr>10) Detection of H emission line – machine learning Train and Test samples: 7000 early-type emission-line stars in DR2 SVML, SVMNL, ANNs and Softmax 23,168 early-type emission-line stars 按照投票的方法，大于3个判断为发射线恒星

Early-type emission-line stars in LAMOST DR4 IR color-color criteria to separate CBe and HAeBe H-K vs J-H: Hernandez et al.(2005) H-K vs K-L(W1): Finkenzeller & Mundt(1984) 关于CBe和HAEBE我们同时利用两个红外双色图判决为分类给出更严谨的判别标准

Future Work The photometry properties of early-type emission-line stars color-color diagrams Spectral energy distribution (SED)

Future Work color-color diagrams Evolution scenario of different types U-B vs. B-V J–H vs. H–K H–K vs. K-W1 H–[12] vs. [12]–[60] [12]–[25] vs. [25]–[60 ] 第一个想要开展的工作是基于双色图，通过多个颜色颜色图，来对不同早型发射线恒星的演化阶段以及演化轨迹有更深入的了解

double-component dust model Future Work Multi-band photometric data– SED The mechanism of infrared excess(thermal radiation, or f-f、f-b radiation) The physical properties, structure, formation and evolution of various circumstellar disks for different early-type emission-line stars double-component dust model single dust model 第二个工作是借助多波段测光得到SED，由于不同早型发射线恒星其星周盘具有不同的物理状态，其红外超现象的产生机制也有所不同。通过对SED的分析，我们得到星周盘的物理特性以及几何结构，从而对盘的形成和演化作研究。

Future Work APOGEE and follow-up high-resolution spectra – the structure and physical state of circumstellar disks 当然，进行研究重要的辅助手段，可以对盘的成分结构进行研究，这些也是我们对发射恒星下一步工作的一个初步计划，想法还不是很成熟，请各位老师多提宝贵意见。

Thank you!

Future Work DR4早型发射线恒星光谱和测光特性 早型发射线恒星物理分类 IR color-color判据：CBe和Herbig Ae/Be 恒星 LAMOST光谱区分B[e]恒星：禁线发射- Fe, O, N等 而B[e]的分类依据[Fe]或者[OI]禁线发射

Future Work Multi-band photometric data: optical(ugriz)+IR(JHKW...） SDSS: u, g, r, i, z 在基本的物理分类之后，我们搜集了多波段测光数据分别从以下两个角度研究发射线恒星的测光特性 Pan-STARRS: g, r, i, z, Y