标题： RIOJA 红移6.81星系中由合并引起的结块通过詹姆斯·韦伯空间望远镜揭示 显示英文标题

标题： RIOJA. Merger-induced Clumps in a Galaxy at Redshift 6.81 Revealed by JWST

摘要： 空间分辨的多波长分析对于研究星系形成和演化至关重要。在$z = 6.81$时刻，一个紫外明亮的星系 COS-2987030247 是再电离时代的重要罗塞塔石，由于 RIOJA 计划，可以获得 JWST NIRSpec 积分场光谱、NIRCam 成像和 ALMA 数据。我们从电离氢、氧和氖气体中识别出休息框架光学发射线。[OIII] 5008\AA 线发射和 NIRCam 图像显示了一个复杂的动力学和形态结构，在 10 kpc 范围内识别出两个明亮的主要结团和三个微弱的结团。该系统不是一个简单的旋转盘，而是由合并引起的恒星形成结团组成，这与最近的宇宙学模拟结果一致。空间分辨的发射线流量显示，尘埃消光、金属富集和离化参数在恒星形成峰值处优先增强。 我们的SED拟合表明，主要团块处于中等尘埃遮蔽的恒星形成阶段（$A_{\rm V} = 0.2$--$0.3$以及 SFR(H$\alpha$) $\sim 10$ M$_\odot$ yr$^{-1}$），其电离光子的逃逸分数几乎为零。 相比之下，次级团块没有尘埃，并位于恒星形成星系主序列之上或之下。 这些次级团块可能作为扰动源，通过合并事件触发周围气体中的团块状恒星爆发。 显示英文摘要

摘要： Spatially resolved multi-wavelength analysis is essential to study galaxy formation and evolution. A UV-bright galaxy COS-2987030247 at $z = 6.81$ is one of the Rosetta Stones in the epoch of reionization for which JWST NIRSpec Integral Field Spectroscopy, NIRCam imaging, and ALMA data are available thanks to the RIOJA program. We identified the rest-frame optical emission lines from the ionized hydrogen, oxygen, and neon gas. The [OIII] 5008\AA\ line emission and the NIRCam images show a complex kinematical and morphological structure where two bright main and three faint clumps are identified in a 10 kpc extent. The system is not a simple rotating disk, but instead consists of merger-induced star-forming clumps, as expected from recent cosmological simulations. The spatially resolved emission line fluxes show that dust attenuation, metal enrichment, and ionization parameter are preferentially enhanced in the star formation peaks. Our SED fitting suggests that the main clumps are in a moderately dust-attenuated star forming phase ($A_{\rm V} = 0.2$--$0.3$ and SFR(H$\alpha$) $\sim 10$\,M$_\odot$\,yr$^{-1}$) with almost zero escape fraction of ionizing photons. In contrast, the sub-clumps are dust-free and lying on or below the main sequence of star-forming galaxies. These sub-clumps may work as a perturber that triggers the clumpy starburst in the surrounding gas through the merger event.