AI 中文总结
本研究利用Tomo-e Gozen窄带测光与MALLS中分辨率光谱后续观测，高效选取明亮贫金属恒星，估算约170万颗恒星金属丰度，识别约1.6万颗极贫金属候选星，其中24颗经光谱证认。
AI 中文摘要
我们提出了Tomo-e Gozen明亮贫金属恒星巡天（TeMPS），这是一项针对北天明亮贫金属恒星的大天区窄带测光巡天项目。该巡天使用木曾施密特望远镜（1.05米）上的Tomo-e Gozen相机，配备四个窄带滤光片，中心分别位于电离钙II H和K线、CH G带、Hα以及一个参考波长区域。我们阐述了巡天策略、测光处理，以及基于窄带颜色推导的金属丰度和碳丰度的定标方法。我们还介绍了利用Nayuta/MALLS开展的中分辨率光谱后续观测，以验证测光选源并识别新的贫金属恒星。当前数据集覆盖所有四个波段的天区面积超过22000平方度，总积分时间约100小时。在信噪比为20时的极限星等中位数对应G~12.5。通过将窄带测光与存档宽带测光以及盖亚（Gaia）距离结合，我们估算了有效温度（T_eff）、表面重力对数（log(g)）、金属丰度和碳丰度。与文献中高分辨率光谱得到的丰度相比，定标显示金属丰度的典型散度小于0.3 dex，碳丰度的典型散度小于0.4 dex。我们估算了约170万颗恒星的金属丰度，并识别出约16000颗[M/H]_(NB,fin)<-2的极贫金属候选星。我们证明Nayuta/MALLS中分辨率光谱提供的金属丰度与高分辨率测量结果一致，散度约为0.27 dex。在利用MALLS后续观测的32个测光选源候选星中，24个被证实具有[M/H]_(MALLS)<-2，其中包括一颗新识别的[M/H]_(MALLS)≈-3.4的恒星。这些结果表明，Tomo-e Gozen窄带测光与MALLS中分辨率光谱后续观测能够高效选取明亮贫金属恒星，为未来的高分辨率丰度研究提供样本。
英文摘要
We present the Tomo-e Gozen Bright Metal-Poor Star Survey (TeMPS), a wide-area narrow-band photometric survey for bright metal-poor stars in the northern sky. The survey uses the Tomo-e Gozen camera on the 1.05 m Kiso Schmidt telescope with four narrow-band filters centered on the \ion{Ca}{2} H and K lines, the CH $G$ band, H$α$, and a reference wavelength region. We review the survey strategy, photometric processing, and calibration of metallicity and carbon abundance estimates derived from narrow-band colors. We further present medium-resolution spectroscopic follow-up with Nayuta/MALLS to validate the photometric selection and identify new metal-poor stars. The current data set covers $\gtrsim 22,000$deg$^{2}$ in all four bands with a total integration time of $\sim 100$ hr. The median limiting magnitudes at S/N = 20 correspond to $G\sim12.5$. By combining narrow-band photometry with archival broad-band photometry and {\it Gaia} distances, we estimate $T\_{\rm eff}$, $\log (g)$, metallicity, and carbon abundance. Calibration against literature abundances derived from high-resolution spectra shows typical scatters of $< 0.3$ dex in metallicity and $< 0.4$ dex in carbon abundance. We estimate metallicities for $\sim 1.7$ million stars and identify $\sim 16,000$ very metal-poor candidates with [M/H]$_{\rm NB,fin}<-2$. We show that Nayuta/MALLS medium-resolution spectra provide metallicities consistent with high-resolution measurements, with a scatter of $\sim 0.27$ dex. Among 32 photometrically selected candidates followed up with MALLS, 24 are confirmed to have [M/H]$_{\rm MALLS}< -2$, including one newly identified star with [M/H]$_{\rm MALLS}\simeq -3.4$. These results demonstrate that Tomo-e Gozen narrow-band photometry and MALLS medium-resolution spectroscopic follow-up efficiently select bright metal-poor stars for future high-resolution abundance studies. (abbreviated)
Comments18 pages, 18 figures; submitted to PASJ on May 30 2026
