Spectral Analysis of Host Galaxy from Possible Dual AGNs
文献类型：期刊论文
| 作者 | Wang Meng-xin1,2 ; Luo A-li1,2
|
| 刊名 | SPECTROSCOPY AND SPECTRAL ANALYSIS
 |
| 出版日期 | 2020 |
| 卷号 | 40期号:1页码:290-293 |
| ISSN号 | 1000-0593 |
| 关键词 | LAMOST Dual AGNs Spectral synthesis Stellar population analysis |
| DOI | 10.3964/j.issn.1000-0593(2020)01-0290-04 |
| 英文摘要 | The merger of massive galaxies can also invoke a series of phenomena such as the starburst and SMBH activities, besides galaxies pairing and dual AGNs. When two galaxies merger to kiloparsec (kpc) scale and begin to co-rotate with each other, and the adjacent narrow line regions are sensed by a single spectrograph slit or fiber, double-peaked emission lines would appear in the integrated spectra. In this paper, starting from this observation characteristic, we systematically search for dual AGN candidates whose spectra display double-peaked narrow emission line features in the Data Release 4 of LAMOST survey (LAMOST DR4). The profiles of emission lines of AGN spectra are composed of several different dynamic components, which can be divided into three types including narrow line components (H beta, [O III ], H alpha and [N II ]), wings of [O III] lines, and broad Balmer emission lines. Based on LAMOST DR4 extragalactic spectra, we apply a set of search process, after the initial screening (involving the signal-to-noise ratio, the equivalent width and redshift cuts) and visual check and selection, we establish a sample with double-peaked narrow emission lines, which meets with our criteria of fluxes, full-width-half-maximum and velocity gap between two narrow components in their multi-gaussians fitting. Based on the Baldwin-Phillips-Terlevich (BPT) diagnosis, we finally detect 28 dual AGN candidates. In order to obtain more accurate and find the common characteristics of this kind of dual AGN candidates, we re-correct the spectral flux of these 28 objects with a low-order polynomial and combine them with the traditional interpolation and median method to obtain a high signal-to-noise ratio spectrum. We also take a composite spectra constructed from single type II AGNs in LAMOST DR4 as the control sample. The software STARLIGHT is carried out to fit these two spectra, and the contributions of stars of different ages and metallicities are quantified for more direct comprehension. We find that dual AGN candidates will host more contributions from the middle age and the old populations than the single AGN composite, indicating a more intense central black hole activity. As for the metallicity effects, the dominant stellar population of single AGN is the population with solar metallicity Z(circle dot), while the spectra from dual AGN candidates show a significant contribution from populations with metallicities 0. 2 Z(circle dot) and 2. 5 Z(circle dot), showing a heterogeneous feature and revealing a more complicated star formation history encodes in these possible dual AGNs than it exists in corresponding regular sample. A power-law is considered when we conduct the fitting, and the contributions of this featureless continuum component in single AGN account for 8. 2%, which is significantly higher than that in the dual AGN candidates. |
| WOS关键词 | POPULATION |
| WOS研究方向 | Spectroscopy |
| 语种 | 英语 |
| 出版者 | OFFICE SPECTROSCOPY & SPECTRAL ANALYSIS |
| WOS记录号 | WOS:000512216000049 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/54075]  |
| 专题 | 中国科学院国家天文台 |
| 通讯作者 | Wang Meng-xin |
| 作者单位 | 1.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang Meng-xin,Luo A-li. Spectral Analysis of Host Galaxy from Possible Dual AGNs[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS,2020,40(1):290-293. |
| APA | Wang Meng-xin,&Luo A-li.(2020).Spectral Analysis of Host Galaxy from Possible Dual AGNs.SPECTROSCOPY AND SPECTRAL ANALYSIS,40(1),290-293. |
| MLA | Wang Meng-xin,et al."Spectral Analysis of Host Galaxy from Possible Dual AGNs".SPECTROSCOPY AND SPECTRAL ANALYSIS 40.1(2020):290-293. |
入库方式： OAI收割
来源：国家天文台
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