Automated measurement of quasar redshift with a Gaussian process
Automated measurement of quasar redshift with a Gaussian process
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DOI：
10.1093/mnras/staa2826
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发表时间：
2020-06
影响因子：
4.8
通讯作者：
Leah Fauber;M. Ho;Simeon Bird;C. Shelton;R. Garnett;Ishita Korde
中科院分区：
文献类型：
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作者：
Leah Fauber;M. Ho;Simeon Bird;C. Shelton;R. Garnett;Ishita Korde
我们发展了一种自动化的方法来测量斯隆数字巡天（SDSS）的重子振荡光谱巡天中的类星体红移。我们的技术是早期高斯过程方法的推广，用于探测红移已知的类星体光谱中的阻尼莱曼α吸收体（DLAs）。我们将这种技术应用于SDSS DR 12的子样本，其中删除了BAL类星体，并且红移大于2.15。我们表明，我们是广泛的竞争力，现有的类星体红移估计，不同意PCA红移超过0.5，只有0.38 $$的光谱。我们的方法产生的类星体红移的概率密度函数，允许类星体红移的不确定性传播到下游用户。我们应用这种方法来检测DLAs，占在一个贝叶斯的方式红移的不确定性。与我们早期的方法与已知的类星体红移相比，我们有一个温和的下降，我们的能力，以检测DLAs，主要是在最嘈杂的光谱。曲线下面积从0.96降至0.91。我们的代码是公开的。
We develop an automated technique to measure quasar redshifts in the Baryon Oscillation Spectroscopic Survey of the Sloan Digital Sky Survey (SDSS). Our technique is an extension of an earlier Gaussian process method for detecting damped Lyman α absorbers (DLAs) in quasar spectra with known redshifts. We apply this technique to a subsample of SDSS DR12 with BAL quasars removed and redshift larger than 2.15. We show that we are broadly competitive to existing quasar redshift estimators, disagreeing with the PCA redshift by more than 0.5 in only $0.38{{\ \rm per\ cent}}$ of spectra. Our method produces a probabilistic density function for the quasar redshift, allowing quasar redshift uncertainty to be propagated to downstream users. We apply this method to detecting DLAs, accounting in a Bayesian fashion for redshift uncertainty. Compared to our earlier method with a known quasar redshift, we have a moderate decrease in our ability to detect DLAs, predominantly in the noisiest spectra. The area under curve drops from 0.96 to 0.91. Our code is publicly available.