We present the data of 9739 early-type galaxies (ETGs), cross-matching Galaxy Zoo 1 with our sample selected from the catalog of the Sloan Digital Sky Survey Data Release 7 of MPA-JHU emission-line measurements. We first investigate the divisor between ETGs with and without star formation (SF), and find the best separator of W2–W3= 2.0 is added. We explore the ETG sample by refusing a variety of ionization sources, and derive 5376 ETGs with SF by utilizing a diagnostic tool of the division line of W2–W3=2.0. We measure their metallicities with four abundance calibrators. We find that our composite ETG sample has similar distributions of M _* and star formation rate as star-forming galaxies (SFGs) do, that most of them lie on the “main sequence,” and that our fit is a slightly steeper slope than that derived in Renzini & Peng. Compared with the distributions between different metallicities calibrated by four abundance indicators, we find that the Curti17 method is the most accurate calibrator for composite ETGs among the four abundance indicators. We present a weak positive correlation of SFR and metallicity only when the metallicity is calibrated by the PP04, Curti17, and T04 indicators. The correlation is not consistent with the negative correlation of both parameters in SFGs. We suggest that the weak correlation is due to the dilution effect of gas inflow driven by minor mergers.

我们提供了 9739 个早型星系 (ETG) 的数据，与我们从 MPA-JHU 发射线测量的斯隆数字巡天数据第 7 版目录中选择的样本交叉匹配 Galaxy Zoo 1。我们首先研究了有和没有恒星形成 (SF) 的 ETG 之间的除数，并找到了 W2-W3=2.0 的最佳分离器。我们通过拒绝各种电离源来探索 ETG 样品，并利用 W2-W3=2.0 分界线的诊断工具推导出 5376 个带有 SF 的 ETG。我们用四个丰度校准器测量它们的金属丰度。我们发现我们的复合 ETG 样本具有相似的M _*分布恒星形成星系 (SFG) 所做的和恒星形成率一样，它们中的大多数位于“主序带”上，并且我们的拟合比 Renzini & Peng 推导的斜率略陡。与四个丰度指标校准的不同金属丰度之间的分布进行比较，我们发现 Curti17 方法是四个丰度指标中复合 ETG 最准确的校准器。只有当金属丰度由 PP04、Curti17 和 T04 指标校准时，我们才呈现 SFR 和金属丰度的弱正相关。该相关性与 SFG 中两个参数的负相关性不一致。我们认为弱相关性是由于轻微合并驱动的气体流入的稀释效应。