论文标题

低红移的经验驱动的多波长k校正

Empirically-Driven Multiwavelength K-corrections At Low Redshift

论文作者

Fielder, Catherine E., Andrews, Brett H., Newman, Jeffrey A., Salim, Samir

论文摘要

k校正,观察到的频带中的通量之间的通量转换为静止框带中的通量,对于比较各种红移的星系至关重要。这些校正通常依赖于星系的经验或理论光谱能量分布(SED)模板。但是,模板将可靠的k校正限制为SED模型稳健的政权。例如,在某些频段(例如Wise W4)中,模板没有很好地约束,这会导致这些频段的不确定的K校正。我们通过开发以经验驱动的k校正方法来解决这一缺点,以此来减轻对SED模板的依赖。我们对K校正执行多项式拟合,这是银河系的静止框颜色在受约束良好的频带(例如REST-FRAME(G-R))和RedShift中确定的函数,并利用了星系SED可以将星系SED描述为一个低红色SCHIFT(0.01 <z <z <z <0.09)的一个一个参数家族。对于由SED模板良好约束的频段,我们的经验驱动的k校正与GSWLC-M2目录中使用的KCORECT和SED模板拟合的SED拟合方法相当(更新的中型galex-SDSSSSSSSSS-WISE-WISE遗产目录)。但是,我们的方法极大地优于明智的W4的可用SED拟合K校正。我们的方法还减轻错误的模板假设,并在z = 0处强制k校正为0。我们的K校正的光度法和代码是公开可用的。

K-corrections, conversions between flux in observed bands to flux in rest-frame bands, are critical for comparing galaxies at various redshifts. These corrections often rely on fits to empirical or theoretical spectral energy distribution (SED) templates of galaxies. However, the templates limit reliable K-corrections to regimes where SED models are robust. For instance, the templates are not well-constrained in some bands (e.g., WISE W4), which results in ill-determined K-corrections for these bands. We address this shortcoming by developing an empirically-driven approach to K-corrections as a means to mitigate dependence on SED templates. We perform a polynomial fit for the K-correction as a function of a galaxy's rest-frame color determined in well-constrained bands (e.g., rest-frame (g-r)) and redshift, exploiting the fact that galaxy SEDs can be described as a one parameter family at low redshift (0.01 < z < 0.09). For bands well-constrained by SED templates, our empirically-driven K-corrections are comparable to the SED fitting method of Kcorrect and SED template fitting employed in the GSWLC-M2 catalogue (the updated medium-deep GALEX-SDSS-WISE Legacy Catalogue). However, our method dramatically outperforms the available SED fitting K-corrections for WISE W4. Our method also mitigates incorrect template assumptions and enforces the K-correction to be 0 at z = 0. Our K-corrected photometry and code are publicly available.

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