论文标题
遥远太阳能双胞胎（SDST）的调查-I。恒星参数测量的Epic方法
Survey for Distant Solar Twins (SDST) -- I. EPIC method for stellar parameter measurement
论文作者
论文摘要
太阳能双胞胎是对天文学领域至关重要的明星，并提供了多种科学应用。如今，只有少量（$ \ lyssim200 $）太阳能双胞胎已经知道，所有这些都与我们的太阳相对较近（$ \ lyssim800 \，pc $）。我们对遥远太阳能双胞胎（SDST）调查的目标是将更多的太阳能双胞胎和太阳能模拟星确定到更大的距离（$ \ sim4 \，kpc $）。在本文中，我们提出了一种新方法，使用相对较低的$ s/n $，中等分辨能力（$ r \ sim \ sim 28 {，} 000 $）识别太阳能双胞胎，这将是与爱马仕在$ 3.9 \，m $ $盎格鲁 - 盎格鲁 - 澳大利亚望远镜（AAT）上观察到的远处目标的典型特征。我们开发了一种新颖的方法，即史诗，用于测量我们用来识别类似太阳的恒星的恒星参数。 EPIC determines the stellar atmospheric parameters (effective temperature $T_{\mathrm{eff}}$, surface gravity $\log g$ and metallicity [Fe/H]) using differential equivalent width (EW) measurements of selected spectroscopic absorption features and a simple model, trained on previously analysed spectra, that connects these EWs to the stellar parameters. EW测量值的参考是一个高$ S/N $太阳光谱，用于最大程度地减少几种系统效果。 EPIC快速，针对阳光状的恒星进行了优化，并产生恒星参数测量，并具有足够小的不确定性，可以使用AAT/HERMES使用AAT/HERMES来识别太阳能双胞胎和模拟星，最多可用于$ \ sim4 \，kpc $，即\ $σ\ weft（ \ textrm {[fe/h]} \ right）= \ left（50 \，k，0.08 \，dex，0.03 \，dex \ right）$，平均为$ s/n = 25 $。
Solar twins are stars of key importance to the field of astronomy and offer a multitude of science applications. Only a small number ($\lesssim200$) of solar twins are known today, all of which are relatively close to our Sun ($\lesssim800\,pc$). The goal of our Survey for Distant Solar Twins (SDST) is to identify many more solar twin and solar analogue stars out to much larger distances ($\sim4\,kpc$). In this paper, we present a new method to identify solar twins using relatively low $S/N$, medium resolving power ($R\sim 28{,}000$) spectra that will be typical of such distant targets observed with HERMES on the $3.9\,m$ Anglo-Australian Telescope (AAT). We developed a novel approach, namely EPIC, to measure stellar parameters which we use to identify stars similar to our Sun. EPIC determines the stellar atmospheric parameters (effective temperature $T_{\mathrm{eff}}$, surface gravity $\log g$ and metallicity [Fe/H]) using differential equivalent width (EW) measurements of selected spectroscopic absorption features and a simple model, trained on previously analysed spectra, that connects these EWs to the stellar parameters. The reference for the EW measurements is a high $S/N$ solar spectrum which is used to minimise several systematic effects. EPIC is fast, optimised for Sun-like stars and yields stellar parameter measurements with small enough uncertainties to enable spectroscopic identification of solar twin and analogue stars up to $\sim4\,kpc$ away using AAT/HERMES, i.e.\ $σ\left(T_{\mathrm{eff}}, \log g, \textrm{[Fe/H]}\right) = \left(50\,K, 0.08\,dex, 0.03\,dex\right)$ on average at $S/N=25$.
