Far-infrared Photometric Redshifts: A New Approach to a Highly Uncertain Enterprise
Far-infrared Photometric Redshifts: A New Approach to a Highly Uncertain Enterprise
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DOI：
10.3847/1538-4357/aba528
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发表时间：
2020-07
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通讯作者：
C. Casey
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作者：
C. Casey
本文提出了一种新的方法来推导远红外（FIR）光度红移的星系的基础上，再处理的尘埃在静止帧FIR到毫米波长的辐射。在过去的十年中，FIR测光红移（“FIR-z”）已被用于推导在其他波长（如光学/近红外）缺乏测光的高度模糊星系的红移约束。大多数文献FIR-z拟合是通过最小化单个星系的FIR模板光谱能量分布（SED）来执行的。使用一个单一的星系模板，或适度的模板集，可以导致一个人为的低不确定性估计的FIR-Z的，因为真实的星系显示出广泛的内在尘埃SED。我使用观测到的星系SED的分布（以及约束的样本），以激发一个新的FIR通过毫米测光红移技术称为MMpz。MMpz算法断言，星系最有可能是从经验观察到的静止帧峰值波长，和总红外光度，L之间的关系，推导出的光度红移帐户的测量不确定性和内在的变化在SED在推断的L，以及从宇宙微波背景加热。MMpz算法具有的精度，类似于单模板拟合，同时提供了一个更准确的估计FIR-z的不确定性与减少卡方的顺序相比，替代FIR光度红移技术（与）。
This paper presents a new approach to deriving far-infrared (FIR) photometric redshifts for galaxies based on their reprocessed emission from dust at rest-frame FIR through millimeter wavelengths. FIR photometric redshifts (“FIR-z”) have been used over the past decade to derive redshift constraints for highly obscured galaxies that lack photometry at other wavelengths like the optical/near-IR. Most literature FIR-z fits are performed through minimization to a single galaxy’s FIR template spectral energy distribution (SED). The use of a single galaxy template, or modest set of templates, can lead to an artificially low uncertainty estimate on FIR-z's because real galaxies display a wide range in intrinsic dust SEDs. I use the observed distribution of galaxy SEDs (for well-constrained samples across ) to motivate a new FIR through millimeter photometric redshift technique called MMpz. The MMpz algorithm asserts that galaxies are most likely drawn from the empirically observed relationship between rest-frame peak wavelength, , and total IR luminosity, L ; the derived photometric redshift accounts for the measurement uncertainties and intrinsic variation in SEDs at the inferred L , as well as heating from the cosmic microwave background at . The MMpz algorithm has a precision of , similar to single-template fits, while providing a more accurate estimate of the FIR-z uncertainty with reduced chi-squared of order , compared to alternative FIR photometric redshift techniques (with ).