论文标题
$ z = 7.66 $在JWST观察结果中确定的镜头原始候选者SMACS0723-7327
A lensed protocluster candidate at $z=7.66$ identified in JWST observations of the galaxy cluster SMACS0723-7327
论文作者
论文摘要
根据当前星系构造的范式，第一个星系可能是在大型暗物质光环中形成的。这些巨大的光环的碎裂导致了星系原始群体的形成，它们通常由一个到几个明亮的物体组成，周围是许多淡淡（和较少的）星系。这些早期结构在宇宙的前十亿年内恢复中性氢可以发挥重要作用。特别是，如果它们的数量密度很大。\ textit {James Webb太空望远镜（JWST）}达到的前所未有的灵敏度的优势，现在可以在$ z \ geq \ $ 6的$ z \ geq \ $ 6中识别出星系原始群体。表征他们对紫外线光子预算的贡献可以提供对回电过程的新见解。我们分析了SMACS0723-7327背后的第一个JWST数据集，以搜索$ Z \ GEQ6 $的原始群体，结合了可用的光谱和光度数据。然后，我们将发现与半分析模型和模拟进行比较。除了两个明亮的星系（$ \ leq $ 26.5 ab在F277W中），由$ \ sim $ 11 \ arcsec隔开，并在$ z_ {spec} = 7.66 $上确认，我们还标识了6个其他带有类似颜色的星系，在$ sim20 $ \ arcsecsecsecs $ sim的$ sim a $ sims中（rccssecs $ sim）conce y sim cops y sim rc sim s r c。 飞机）。使用几种方法，我们估计了该原始集群的暗物质晕的质量，$ \ sim $ 3.3 $ \ times $ 10 $^{11} $ m $ _ {\ odot} $ cargecting用于放大倍率，与各种预测一致。所有原始构件的物理特性也与先前在较低的红移（恒星形成主序列和原始群集尺寸）上发现的物理特性非常吻合。该检测增加了目前在宇宙前十亿年中闻名的几个原始群体。
According to the current paradigm of galaxy formation, the first galaxies have been likely formed within large dark matter haloes. The fragmentation of these massive haloes led to the formation of galaxy protoclusters, which are usually composed of one to a few bright objects, surrounded by numerous fainter (and less massive) galaxies. These early structures could have played a major role in reionising the neutral hydrogen within the first billion years of the Universe; especially, if their number density is significant.Taking advantage of the unprecedented sensitivity reached by the \textit{James Webb Space Telescope (JWST)}, galaxy protoclusters can now be identified and studied in increasing numbers beyond $z\geq\ $6. Characterising their contribution to the UV photon budget could supply new insights into the reionisation process. We analyse the first JWST dataset behind SMACS0723-7327 to search for protoclusters at $z\geq6$, combining the available spectroscopic and photometric data. We then compare our findings with semi-analytical models and simulations. In addition to two bright galaxies ($\leq$26.5 AB in F277W), separated by $\sim$11\arcsec and spectroscopically confirmed at $z_{spec}=7.66$, we identify 6 additional galaxies with similar colors in a $θ\sim20$\arcsec radius around these (corresponding to R$\sim60-90$ kpc in the source plane). Using several methods, we estimate the mass of the dark matter halo of this protocluster, $\sim$3.3$\times$10$^{11}$M$_{\odot}$ accounting for magnification, consistent with various predictions. The physical properties of all protocluster members are also in excellent agreement with what has been previously found at lower redshifts: star-formation main sequence and protocluster size. This detection adds to just a few protoclusters currently known in the first billion years of the universe.
