标题： AURORA巡天：一个极其成熟的恒星形成星系$z\sim 7$ 显示英文标题

标题： The AURORA Survey: An Extraordinarily Mature, Star-forming Galaxy at $z\sim 7$

摘要： 我们展示了质量大、尺度大、尘埃丰富、富含金属的恒星形成星系 GOODSN-100182 的性质，该星系的光谱红移为 z_spec=6.73。GOODSN-100182 是作为 AURORA 巡天的一部分使用 JWST/NIRSpec 观测到的，并且也被公共多波段 HST 和 JWST 成像所覆盖。尽管在 JWST 之前通过其较大的恒星质量（~10^10 M_sun）已经指示了 GOODSN-100182 的存在，但如今 NIRCam 的休息光学成像揭示了一个扩展盘的存在（r_eff~1.5 kpc）。此外，GOODSN-100182 的 NIRSpec R~1000 光谱包括了从 [OII]3727 到 [NII]6583 波长范围内的一系列休息光学星云发射线的检测。巴耳末线系的比例表明显著的尘埃消光（E(B-V)_gas=0.40+0.10/-0.09），这与为 GOODSN-100182 推断出的红色休息紫外斜率（beta=-0.50+/-0.09）一致。基于修正尘埃后的 H-alpha 发射计算得出的恒星形成率为 log(SFR(H-alpha)/M_sun/yr)=2.02+0.13/-0.14，在特定恒星形成率方面远高于 z~7 的恒星形成主序列。值得注意的是，[NII]6583/H-alpha 发射的比例几乎表明太阳金属丰度，这一点也由 ([OIII]5007/H-beta)/([NII]6583/H-alpha) 比值以及微弱的 [FeII]4360 发射特征的检测所支持。总体而言，GOODSN-100182 的激发和电离特性更接近于 z~2-3 的典型恒星形成星系，而非 z~7 的星系。基于 GOODS-N 区域的公共光谱，我们发现 GOODSN-100182 位于一个显著的星系过密区域，并伴随有一个光谱确认的邻近星系。GOODSN-100182 表明在宇宙时间的第一十亿年内就存在成熟的、化学富集的星系，这些星系的性质必须由星系形成模型来解释。 显示英文摘要

摘要： We present the properties of a massive, large, dusty, metal-rich, star-forming galaxy at z_spec=6.73. GOODSN-100182 was observed with JWST/NIRSpec as part of the AURORA survey, and is also covered by public multi-wavelength HST and JWST imaging. While the large stellar mass of GOODSN-100182 (~10^10 M_sun) was indicated prior to JWST, NIRCam rest-optical imaging now reveals the presence of an extended disk (r_eff~1.5 kpc). In addition, the NIRSpec R~1000 spectrum of GOODSN-100182 includes the detection of a large suite of rest-optical nebular emission lines ranging in wavelength from [OII]3727 up to [NII]6583. The ratios of Balmer lines suggest significant dust attenuation (E(B-V)_gas=0.40+0.10/-0.09), consistent with the red rest-UV slope inferred for GOODSN-100182 (beta=-0.50+/-0.09). The star-formation rate based on dust-corrected H-alpha emission is log(SFR(H-alpha)/ M_sun/yr)=2.02+0.13/-0.14, well above the z~7 star-forming main sequence in terms of specific SFR. Strikingly, the ratio of [NII]6583/H-alpha emission suggests almost solar metallicity, as does the ratio ([OIII]5007/H-beta)/([NII]6583/H-alpha) and the detection of the faint [FeII]4360 emission feature. Overall, the excitation and ionization properties of GOODSN-100182 more closely resemble those of typical star-forming galaxies at z~2-3 rather than z~7. Based on public spectroscopy of the GOODS-N field, we find that GOODSN-100182 resides within a significant galaxy overdensity, and is accompanied by a spectroscopically-confirmed neighbor galaxy. GOODSN-100182 demonstrates the existence of mature, chemically-enriched galaxies within the first billion years of cosmic time, whose properties must be explained by galaxy formation models.