MICADO 用于 ELT 的首光成像仪：宇宙正午恒星形成团块的模拟观测
The MICADO first light imager for the ELT: Simulated Observations of Star Forming Clumps at Cosmic Noon
- INAF - Osservatorio Astronomico di Padova（意大利国家天体物理研究所帕多瓦天文台）
- INAF - Osservatorio Astronomico d’Abruzzo（意大利国家天体物理研究所阿布鲁佐天文台）
- INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna（意大利国家天体物理研究所博洛纳天文物理与空间科学观测站）
- European Southern Observatory（欧洲南方天文台）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本文评估 ELT 的 MICADO 仪器通过模拟观测表征非透镜 z=2 星系中恒星形成团块的能力，证明其可探测至 R_e~20 pc 的团块，填补关键观测空白。
中文摘要 AI 辅助
红移 z~2-6 的星系表现出显著的恒星形成区域（团块）。对这些星系结构的表征需要高灵敏度和约 100 pc 或更小的空间分辨率。目前，这些空间尺度只有借助强引力透镜才能实现。然而，透镜会引入依赖于模型的不确定性，并将样本限制在大质量星系团后面的星系。即将到来的 40 米级望远镜，如 ESO 极大望远镜（ELT），将能够对普遍存在的、非透镜的 z≥2 星系中的团块进行常规研究。我们评估了 ELT 的首光成像仪和光谱仪 MICADO 表征非透镜 z=2 星系中团块的能力。具体来说，我们关注两个具有代表性的观测场景，为仪器的早期科学利用提供基础。我们在一个理想化的 z=2 恒星形成星系中模拟了团块，并生成了宽带和窄带成像的模拟 MICADO 观测。后者利用团块典型的强发射线来提高探测和表征能力。在最佳观测条件下，MICADO 能够达到 UV 静止系星等低至 M_UV ~ -15 的团块，将能够高效地表征非透镜 z=2 星系中低至 R_e ~ 20 pc 的团块。此外，MICADO 约 1 角分^2 的完整视场能够高效地对多个目标进行巡天。这项研究证明了 MICADO 填补关键观测空白的潜力，为宇宙正午的团块形成和演化提供新的见解。精确的 PSF 重建对于充分利用这一能力至关重要，因为它显著影响团块的探测和表征，尤其是在最小尺寸（<40 pc）下。
英文摘要
Galaxies at redshift z$\sim$2-6 exhibit prominent star-forming regions (clumps). Characterisation of these galactic structures requires both high sensitivity and spatial resolution of $\sim$100 pc or less. Currently, these spatial scales are achievable only with the aid of strong gravitational lensing. However, lensing introduces model-dependent uncertainties and limits the sample to galaxies behind massive clusters. The upcoming 40m-class telescopes, such as the ESO Extremely Large Telescope (ELT), will enable routine studies of clumps in ubiquitous, non-lensed z$\ge$2 galaxies. We assess the capability of MICADO, the first-light imager and spectrograph of the ELT, to characterise clumps in non-lensed z=2 galaxies. Specifically, we focus on two representative observing scenarios, providing the basis for an early scientific exploitation of the instrument. We modelled clumps in an idealised z=2 star-forming galaxy and produced mock MICADO observations in both broad- and narrow-band imaging. The latter leverages the strong emission lines typical of clumps to improve detection and characterisation. Reaching UV rest-frame magnitudes of clumps as faint as M$_{UV} \sim -15$ in optimal observing conditions, MICADO will be able to efficiently characterise clumps in non-lensed z=2 galaxies down to R$_{e} \sim 20$ pc. Moreover, the full MICADO $\sim$1 arcmin$^2$ field of view enables efficient surveys of multiple targets. This study demonstrates MICADO's potential to fill a crucial observational gap, shedding new light on clump formation and evolution at cosmic noon. Accurate PSF reconstruction will be crucial to fully harness this capability as it significantly impacts clump detection and characterisation, especially at the smallest sizes ($<$40 pc).
