发表机构
Kavli Institute for Cosmology, University of Cambridge; Cavendish Laboratory, University of Cambridge; Department for Astrophysical and Planetary Science, University of Colorado, Boulder; Department of Physics, University of Oxford; Steward Observatory, University of Arizona; Department of Astronomy, The University of Texas at Austin; Cosmic Frontier Center, The University of Texas at Austin; Department of Astronomy and Astrophysics, University of California, Santa Cruz（剑桥大学卡弗里宇宙学研究所; 剑桥大学卡文迪许实验室; 科罗拉多大学博尔德分校天文与行星科学系; 牛津大学物理系; 亚利桑那大学斯图尔德天文台; 德克萨斯大学奥斯汀分校天文学系; 德克萨斯大学奥斯汀分校前沿宇宙中心; 加州大学圣克鲁兹分校天文与天体物理学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出贝叶斯框架实现JWST/NIRSpec密挡板光谱的源-谱线关联，结合交叉色散偏移、波长一致性和相对谱线位置变化，在模拟中实现98%红移准确率，实现高效高完备的高红移巡天。
AI 中文摘要
我们展示了在 JWST/NIRSpec 密挡板光谱中实现源-谱线关联的可行性，每次观测可同时观测约2000个源，且不受光谱重叠的影响。虽然 JWST 宽场无缝光谱（WFSS）可以通过使用两个色散方向垂直的光栅来分离重叠光谱，但 NIRSpec 可以利用具有不同色散的光栅来实现这一点。与 WFSS 相比，NIRSpec 密挡板光谱提供了显著更高的灵敏度和更宽的波长覆盖范围。我们开发了一个贝叶斯框架，结合交叉色散偏移、波长一致性以及光栅之间相对谱线位置的变化，来联合确定源关联和红移。我们使用基于 JWST 高级深空河外星系巡天（JADES）观测到的源分布和发射线通量的模拟观测来测试该方法，并考虑了 NIRSpec 光学模型、MSA 可操作性、测量噪声、误检和坏像素。尽管光谱迹线广泛重叠，但在 NIRSpec 光栅光谱中，模拟发射线中仅有不到0.5%的谱线在探测器上与其他谱线混合。将我们的方法应用于这些模拟，我们为约1800个具有可检测发射线的源获得了红移，准确率为98%，其中约1500个被归类为高置信度，且准确率达99.9%。我们进一步研究了关联准确度如何依赖于光栅配置的数量。通过结合高复用、高灵敏度和宽波长覆盖，NIRSpec 密挡板光谱能够为高红移宇宙实现高效、高完备性的光谱巡天。
英文摘要
We demonstrate the feasibility of source--line association in JWST/NIRSpec dense-shutter spectroscopy, with $\sim$2000 sources observed simultaneously per pointing regardless of spectral overlap. While JWST wide-field slitless spectroscopy (WFSS) can disentangle overlapping spectra using two grisms with perpendicular dispersion directions, NIRSpec can achieve this using gratings with different dispersions. Compared with WFSS, NIRSpec dense-shutter spectroscopy offers substantially higher sensitivity and broader wavelength coverage. We develop a Bayesian framework that combines cross-dispersion offsets, wavelength consistency, and changes in relative line positions between gratings to jointly determine source associations and redshifts. We test the method using mock observations based on the observed source distribution and emission-line fluxes from the JWST Advanced Deep Extragalactic Survey (JADES), accounting for the NIRSpec optical model, MSA operability, measurement noise, false-positive detections, and bad pixels. Although the spectral traces overlap extensively, fewer than 0.5% of the simulated emission lines are blended with another line on the detectors in NIRSpec grating spectroscopy. Applying our method to these simulations, we obtain redshifts, at an accuracy of 98%, for the $\sim$1800 sources that have detectable emission lines, of which $\sim$1500 are classified as confident and are 99.9% accurate. We further investigate how the association accuracy depends on the number of grating configurations. By combining high multiplexing, high sensitivity, and broad wavelength coverage, NIRSpec dense-shutter spectroscopy enables efficient, highly complete spectroscopic surveys for the high-redshift Universe.
