论文标题
看到更尖锐，更深的：JWST在复制时期的星系的光度和光谱特性的第一眼
Seeing sharper and deeper: JWST's first glimpse of the photometric and spectroscopic properties of galaxies in the epoch of reionisation
论文作者
论文摘要
我们分析了SMACS 0723 JWST早期释放观测场中四个星系（EOR）中四个星系的光度和光谱特性。鉴于这些来源的已知光谱红移，我们研究了仅使用NIRCAM光度计来得出光度光度的准确性，发现F115W成像对于区分高等效宽度（EW）[O III]λ5007发射和Z〜10 Balmer balemer bearmer breakmer breakalax的Z〜8星系至关重要。我们发现，所有四个来源都表现出强（\ geq 0.6 mag）F356W-F444W颜色，它们位于数值模拟的理论预测的极端。我们发现这些星系（大约0.5个DEX）偏离了[O III]λ5007/HβAND[NE III]λ3869/[O II]之间的局部相关性，这与具有升高线激发比率的高红色星系的模拟相一致。我们直接从光谱法直接测量[O III]λ5007等效宽度，并且是从强大的F356W-F444W颜色中学到的，从而发现了很大的[O III]λ5007EWS 225-1740Å。 [O III]λ5007和HβEWS与局部宇宙中极端，恒星形成的矮星系中看到的[O III]和HβEWS一致。我们的结构分析表明，这些星系已解决，表现出具有明亮团块的不规则形状。与流体动力模拟的预测相一致，这种强烈的恒星形成和极端的雾化条件可能是EOR中的规范，而不是例外。
We analyse the photometric and spectroscopic properties of four galaxies in the epoch of reionisation (EoR) within the SMACS 0723 JWST Early Release Observations field. Given the known spectroscopic redshifts of these sources, we investigated the accuracy with which photometric redshifts can be derived using NIRCam photometry alone, finding that F115W imaging is essential to distinguish between z~8 galaxies with high equivalent width (EW) [O III] λ5007 emission and z~10 Balmer break galaxies. We find that all four sources exhibit strong (\geq 0.6 mag) F356W-F444W colours, which sit at the extreme end of theoretical predictions from numerical simulations. We find that these galaxies deviate (by roughly 0.5 dex) from the local correlation between [O III] λ5007/Hβand [Ne III] λ3869/[O II], which is consistent with the predictions from simulations of high-redshift galaxies having elevated line excitation ratios. We measure the [O III] λ5007 rest-frame equivalent widths both directly from the spectroscopy, and indirectly as inferred from the strong F356W-F444W colours, finding large [O III] λ5007 EWs of 225-1740 Å. The [O III] λ5007 and HβEWs are consistent with those seen in extreme, intensely star-forming dwarf galaxies in the local Universe. Our structural analysis indicates that these galaxies are resolved, exhibiting irregular shapes with bright clumps. In line with the predictions from the FLARES hydrodynamic simulations, such intense star formation and extreme nebular conditions are likely the norm, rather than the exception, in the EoR.
