标题： 星尘巡天观测星系中的恒星结构（S$^4$G）：基于3.6微米自动消光校正的精确恒星质量分布 显示英文标题

标题： The Spitzer Survey of Stellar Structure in Galaxies (S$^4$G): Precise Stellar Mass Distributions from Automated Dust Correction at 3.6 microns

摘要： 中红外是追踪近邻星系恒星质量的一个理想窗口，3.6$\mu m$IRAC波段已经被用来达到这个目的，但是这样的质量估计可能会受到尘埃发射的影响。 我们展示了我们的流程以揭示3.6$\mu m$处的古老恒星通量，并为超过1600个来自斯皮策星系恒星结构调查（S$^{4}$G）的星系获得恒星质量图。 该调查包括两个红外波段（3.6和4.5$\mu m$）的图像，我们使用Meidt等人（2012年）提出的独立成分分析（ICA）方法来分离古老恒星的主要光线和尘埃发射，这些尘埃发射可以显著贡献于观测到的3.6$\mu m$流量。 我们将信号噪声比低（信噪比<10）以及原始[3.6]-[4.5]颜色与古老恒星群体一致（表明尘埃发射很少）的星系从我们的ICA分析中排除（主要是早期哈勃类型，可以直接提供良好的质量图）。 对于成功应用ICA的剩余1251个星系，我们发现3.6$\mu m$总光度中有10-30%通常来自尘埃，局部情况下甚至更高。 这种污染比例与特定恒星形成率显示出相关性，证实了我们检测到的尘埃发射与恒星形成有关。 此外，我们利用大量的质量估计样本，以观测到的 [3.6]-[4.5] 颜色为函数，校准了有效质光比 ($M/L$) 与 ($\log(M/L)=-0.339 (\pm 0.057) \times ([3.6]-[4.5]) -0.336 (\pm 0.002)$) 的关系。 我们的最终管道产品已通过 IRSA 向公众开放，为天文界提供了前所未有的大量现成用于科学研究的恒星质量图。 显示英文摘要

摘要： The mid-infrared is an optimal window to trace stellar mass in nearby galaxies and the 3.6$\mu m$ IRAC band has been exploited to this effect, but such mass estimates can be biased by dust emission. We present our pipeline to reveal the old stellar flux at 3.6$\mu m$ and obtain stellar mass maps for more than 1600 galaxies available from the Spitzer Survey of Stellar Structure in Galaxies (S$^{4}$G). This survey consists of images in two infrared bands (3.6 and 4.5$\mu m$), and we use the Independent Component Analysis (ICA) method presented in Meidt et al. (2012) to separate the dominant light from old stars and the dust emission that can significantly contribute to the observed 3.6$\mu m$ flux. We exclude from our ICA analysis galaxies with low signal-to-noise ratio (S/N < 10) and those with original [3.6]-[4.5] colors compatible with an old stellar population, indicative of little dust emission (mostly early Hubble types, which can directly provide good mass maps). For the remaining 1251 galaxies to which ICA was successfully applied, we find that as much as 10-30% of the total light at 3.6$\mu m$ typically originates from dust, and locally it can reach even higher values. This contamination fraction shows a correlation with specific star formation rates, confirming that the dust emission that we detect is related to star formation. Additionally, we have used our large sample of mass estimates to calibrate a relationship of effective mass-to-light ratio ($M/L$) as a function of observed [3.6]-[4.5] color: $\log(M/L)=-0.339 (\pm 0.057) \times ([3.6]-[4.5]) -0.336 (\pm 0.002)$. Our final pipeline products have been made public through IRSA, providing the astronomical community with an unprecedentedly large set of stellar mass maps ready to use for scientific applications.