MUSE-Wide

We present the MUSE-Wide survey, a blind, 3D spectroscopic survey in the CANDELS/GOODS-S and CANDELS/COSMOS regions. Each MUSE-Wide pointing has a depth of 1 hour and hence targets more extreme and more luminous objects over 10 times the area of the MUSE-Deep fields (Bacon et al. 2017). The legacy value of MUSE-Wide lies in providing "spectroscopy of everything" without photometric pre-selection. We describe the data reduction, post-processing and PSF characterization of the first 44 CANDELS/GOODS-S MUSE-Wide pointings released with this publication. Using a 3D matched filtering approach we detected 1,602 emission line sources, including 479 Lyman-α (Lya) emitting galaxies with redshifts 2.9≲z≲6.3. We cross-match the emission line sources to existing photometric catalogs, finding almost complete agreement in redshifts and stellar masses for our low redshift (z 1.5) emitters. At high redshift, we only find ~55% matches to photometric catalogs. We encounter a higher outlier rate and a systematic offset of Δz≃0.2 when comparing our MUSE redshifts with photometric redshifts. Cross-matching the emission line sources with X-ray catalogs from the Chandra Deep Field South, we find 127 matches, including 10 objects with no prior spectroscopic identification. Stacking X-ray images centered on our Lya emitters yielded no signal; the Lya population is not dominated by even low luminosity AGN. A total of 9,205 photometrically selected objects from the CANDELS survey lie in the MUSE-Wide footprint, which we provide optimally extracted 1D spectra of. We are able to determine the spectroscopic redshift of 98% of 772 photometrically selected galaxies brighter than 24th F775W magnitude. All the data in the first data release - datacubes, catalogs, extracted spectra, maps - are available at the website.

本报告呈现了MUSE-Wide巡天项目，该项目在CANDELS/GOODS-S和CANDELS/COSMOS区域进行了一项盲目的3D光谱巡天。每个MUSE-Wide观测点的观测深度为1小时，因此覆盖了面积超过MUSE-Deep场10倍以上，并针对更极端、更明亮的物体进行观测（Bacon等，2017年）。MUSE-Wide的遗产价值在于它提供了无需光电预选的“一切光谱”服务。本文详细描述了随本出版物一同发布的首44个CANDELS/GOODS-S MUSE-Wide观测点的数据处理、后处理以及点扩展函数（PSF）表征。通过采用3D匹配滤波技术，我们探测到了1602个发射线源，其中包括479个具有2.9≤z≤6.3红移的莱曼-α（Lya）发射星系。我们将发射线源与现有的光电目录进行交叉匹配，发现对于低红移（z≤1.5）的发射体，其在红移和恒星质量上的数据几乎完全一致。在高红移情况下，我们仅在光电目录中找到了约55%的匹配项。在将我们的MUSE红移与光电红移进行比较时，我们遇到了较高的异常率以及系统偏差Δz≃0.2。通过将发射线源与来自Chandra Deep Field South的X射线目录进行交叉匹配，我们找到了127个匹配项，包括10个之前未进行光谱识别的对象。将聚焦于我们莱曼-α发射体的X射线图像进行堆叠，未产生任何信号；莱曼-α群体并非由即使是低亮度活动星系核（AGN）所主导。来自CANDELS巡天的总计9,205个光电选定的物体位于MUSE-Wide覆盖范围内，我们提供了最优提取的1D光谱。我们能够确定772个光电选定的、亮度大于24th F775W量级的星系的98%的光谱红移。第一版数据发布中包含的所有数据——数据立方体、目录、提取的光谱、图——均可在网站上获取。