标题： 附近S0星系的核活动 显示英文标题

标题： The Nuclear Activities of Nearby S0 Galaxies

摘要： 我们研究了附近S0星系中的核活动。 在将斯隆数字巡天数据发布7 (SDSS DR7) 与第三亮星系参考目录 (RC3) 进行交叉匹配，并手动检查SDSS图像后，我们得出一个包含583个S0星系的样本，这些星系具有中心光度信息。 为了将电离气体发射线与潜在的恒星贡献分开，我们将恒星种群模型拟合到这些S0星系的SDSS光谱上。 根据BPT图，我们发现$8\%$的S0星系显示出中心恒星形成活动，而塞弗特星系、复合型和低电离核发射线区的比例分别为2%、8%和21.4%。 我们还发现，恒星形成S0星系的质量最低，比其他类型低一个数量级，而活跃的S0星系主要位于稀疏环境中，而正常的S0星系则位于密集环境中，这可能表明环境在抑制S0星系中恒星形成和/或AGN活动方面起着重要作用。 通过使用二维拟合软件\textsc{Galfit}对45个恒星形成S0星系在{\em g}和{\em r}波段进行核球-盘分解，并利用\citet{Meert2015}的二维光度分解目录，我们发现$\sim$1/3 的恒星形成S0星系（16/45）的核球比其盘更蓝，而对于其他类型的S0星系，核球和盘组分表现出相似的颜色分布。 此外，大多数恒星形成S0星系核球的Sérsic指数小于2，而对于正常S0星系，该指数在2到6之间。 显示英文摘要

摘要： We present a study of nuclear activities in nearby S0 galaxies. After cross-matching the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) with the Third Reference Catalog of Bright Galaxies (RC3) and visually checking the SDSS images, we derive a sample of 583 S0 galaxies with the central spectrophotometric information. In order to separate nebular emission lines from the underlying stellar contribution, we fit the stellar population model to the SDSS spectra of these S0 galaxies. According to the BPT diagram, we find that $8\%$ of S0 galaxies show central star-forming activity, while the fractions of Seyfert, Composite and LINERs are 2\%, 8\%, and 21.4\%, respectively. We also find that star-forming S0s have the lowest stellar masses, over one magnitude lower than the others, and that the active S0s locate mainly in the sparse environment, while the normal S0s in the dense environment, which might suggest that the environment plays an important role in quenching star formation and/or AGN activity in S0 galaxies. By performing bulge-disk decomposition of 45 star-forming S0s in {\em g}- and {\em r}-bands with the 2D fitting software \textsc{Galfit}, as well as exploiting the catalog of 2D photometric decompositions of \citet{Meert2015}, we find that the bulges of $\sim$ 1/3 star-forming S0 galaxies (16/45) are bluer than their disks, while for other types of S0s, the bulge and disk components show similar color distributions. Besides, the S\'{e}rsic index of most star-forming S0s bulges is less than 2, while for normal S0s, it is between 2 and 6.