Constraining the Milky Way’s ultraviolet to infrared SED with Gaussian Process Regression
Constraining the Milky Way’s ultraviolet to infrared SED with Gaussian Process Regression
复制标题
用高斯过程回归约束银河系的紫外到红外 SED
DOI：
10.1093/mnras/stab2618
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发表时间：
2021
影响因子：
4.8
通讯作者：
S. Salim
中科院分区：
文献类型：
--
作者：
Catherine E. Fielder;J. Newman;B. Andrews;G. Zasowski;N. Boardman;Timothy C. Licquia;K. Masters;S. Salim
提高我们对全球银河系 (MW) 特性的了解对于将只能在银河系内部进行的详细测量与我们对更广泛的星系群的理解联系起来至关重要。我们在 SDSS 星系上训练高斯过程回归 (GPR) 模型，以将星系属性（恒星质量、视轴比、恒星形成率、核球与总比、圆盘尺度长度和条形投票分数）映射到 UV (GALEX FUV/NUV)、光学 (SDSS ugriz) 和 IR (2MASS JHKs 和 WISE W1/W2/W3/W4) 通量和不确定性。通过这些模型，我们可以估计 MW 的光度特性，从而获得完整的紫外到红外光谱能量分布 (SED)，就像从外部测量、正面观察一样。我们在光学诊断图中确认了银河系位于绿色山谷中，但在标准紫外和红外诊断中首次表明MW位于恒星形成区域——这是红色螺旋星系群体的特征。尽管我们的 GPR 方法一次预测一个波段，但所得的 MW UV-IR SED 与局部螺旋的 SED 一致，其特征与 MW 大致相似，这表明这些独立的预测可以可靠地组合起来。我们的紫外-红外 SED 对于使用与外部星系相同的工具重建 MW 的恒星形成历史非常宝贵，可以将原位测量的结果与用于星系外天体的方法的结果进行比较。
Improving our knowledge of global Milky Way (MW) properties is critical for connecting the detailed measurements only possible from within our Galaxy to our understanding of the broader galaxy population. We here train Gaussian Process Regression (GPR) models on SDSS galaxies to map from galaxy properties (stellar mass, apparent axial ratio, star formation rate, bulge-to-total ratio, disk scale length, and bar vote fraction) to UV (GALEX FUV/NUV), optical (SDSS ugriz) and IR (2MASS JHKs and WISE W1/W2/W3/W4) fluxes and uncertainties. With these models we estimate the photometric properties of the MW, resulting in a full UV-to-IR spectral energy distribution (SED) as it would be measured externally, viewed face-on. We confirm that the Milky Way lies in the green valley in optical diagnostic diagrams, but show for the first time that the MW is in the star-forming region in standard UV and IR diagnostics—characteristic of the population of red spiral galaxies. Although our GPR method predicts one band at a time, the resulting MW UV–IR SED is consistent with SEDs of local spirals with characteristics broadly similar to the MW, suggesting that these independent predictions can be combined reliably. Our UV–IR SED will be invaluable for reconstructing the MW’s star formation history using the same tools employed for external galaxies, allowing comparisons of results from in situ measurements to those from the methods used for extra-galactic objects.