Optimal 1D Ly a forest power spectrum estimation - III. DESI early data
Optimal 1D Ly a forest power spectrum estimation - III. DESI early data
复制标题
最优一维 Ly 森林功率谱估计 - III。
DOI：
10.1093/mnras/stae171
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发表时间：
2024
影响因子：
4.8
通讯作者：
Karaçayli N
中科院分区：
文献类型：
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作者：
Karaçayli N
Ly α森林的一维功率谱p1dd提供了关于宇宙学和天体物理参数的重要信息，包括对热暗物质模型的约束、三种中微子的质量总和以及星系间介质的热状态。本文首次利用暗能量谱仪（DESI）调查早期数据样本的二次极大似然估计（QMLE）测量了p1d。这个早期的54 600个类星体样本的大小已经可以与之前最大的研究相媲美，我们对许多仪器和分析系统误差进行了彻底的调查，以评估它们对QMLE DESI数据的影响。我们通过用DESI光谱管道处理的原始DESI图像的二维图像模拟，证明了光谱管道噪声估计的优异性能和光谱仪分辨率矩阵的令人印象深刻的精度。我们还研究了利用类星体光谱在Ly α发射线红色一侧的金属线污染和噪声校准系统。在另一篇论文中，我们提出了基于快速傅立叶变换估计功率谱的类似分析。最后，我们对这两种方法进行了比较，并讨论了我们需要在即将到来的DESI第一年分析中解决的系统误差的主要来源。
The 1D power spectrumP1Dof the Ly α forest provides important information about cosmological and astrophysical parameters, including constraints on warm dark matter models, the sum of the masses of the three neutrino species, and the thermal state of the intergalactic medium. We present the first measurement ofP1Dwith the quadratic maximum likelihood estimator (QMLE) from the Dark Energy Spectroscopic Instrument (DESI) survey early data sample. This early sample of 54 600 quasars is already comparable in size to the largest previous studies, and we conduct a thorough investigation of numerous instrumental and analysis systematic errors to evaluate their impact on DESI data with QMLE. We demonstrate the excellent performance of the spectroscopic pipeline noise estimation and the impressive accuracy of the spectrograph resolution matrix with 2D image simulations of raw DESI images that we processed with the DESI spectroscopic pipeline. We also study metal line contamination and noise calibration systematics with quasar spectra on the red side of the Ly α emission line. In a companion paper, we present a similar analysis based on the Fast Fourier Transform estimate of the power spectrum. We conclude with a comparison of these two approaches and discuss the key sources of systematic error that we need to address with the upcoming DESI Year 1 analysis.