Firefly (Fitting IteRativEly For Likelihood analYsis): a full spectral fitting code
Firefly (Fitting IteRativEly For Likelihood analYsis): a full spectral fitting code
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DOI：
10.1093/mnras/stx2215
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发表时间：
2017-11
影响因子：
4.8
通讯作者：
D. Wilkinson;C. Maraston;D. Goddard;D. Thomas;T. Parikh
中科院分区：
文献类型：
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作者：
D. Wilkinson;C. Maraston;D. Goddard;D. Thomas;T. Parikh
我们提出了一个新的光谱拟合程序，萤火虫，推导恒星系统的恒星人口的性质。Firefly是一个卡方最小化拟合代码，它将单次爆发恒星种群模型的组合拟合到光谱数据，遵循由贝叶斯信息准则控制的迭代最佳拟合过程。不应用先验，而是保留统计切割内的所有解决方案及其权重。此外，没有加性或乘性多项式被用来调整频谱形状。这种拟合自由度的设想，以映射出的内在光谱能量分布（SED）退化，如年龄，金属丰度，尘埃变红星系属性的影响，并量化不同的输入模型组件对这些属性的影响。尘埃衰减包括使用一个新的程序，这是测试积分场光谱（IFS）的数据在以前的文件。拟合方法进行了广泛的测试与一套全面的模拟星系，真实的星系从斯隆数字巡天和银河系球状星团。我们还评估了作为信噪比和采用波长范围的函数的衍生属性的鲁棒性。我们表明，对于中等尘埃系统，\FF\能够将年龄、金属丰度、恒星质量甚至星星形成历史恢复到$S/N\sim 5 $。代码和结果可在www.icg.port.ac.uk/firefly上公开获取。
We present a new spectral fitting code, Firefly, for deriving the stellar population properties of stellar systems. Firefly is a chi-squared minimisation fitting code that fits combinations of single-burst stellar population models to spectroscopic data, following an iterative best-fitting process controlled by the Bayesian Information Criterion. No priors are applied, rather all solutions within a statistical cut are retained with their weight. Moreover, no additive or multiplicative polynomia are employed to adjust the spectral shape. This fitting freedom is envisaged in order to map out the effect of intrinsic spectral energy distribution (SED) degeneracies, such as age, metallicity, dust reddening on galaxy properties, and to quantify the effect of varying input model components on such properties. Dust attenuation is included using a new procedure, which was tested on Integral Field Spectroscopic (IFS) data in a previous paper. The fitting method is extensively tested with a comprehensive suite of mock galaxies, real galaxies from the Sloan Digital Sky Survey and Milky Way globular clusters. We also assess the robustness of the derived properties as a function of signal-to-noise ratio and adopted wavelength range. We show that \FF\ is able to recover age, metallicity, stellar mass and even the star formation history remarkably well down to a $S/N\sim5$, for moderately dusty systems. Code and results are publicly available at www.icg.port.ac.uk/firefly.