State-of-the-art rest-frame UV and FIR photometric and spectroscopic observations are now pushing the redshift frontiers of galaxy formation studies up to $z\sim9-11$ and beyond. Recent HST observations unveiled the presence of a star-forming galaxy exhibiting the Lyman break at $λ_{\rm obs}=1.47\pm0.01$ $μ$m, i.e., a $z=11.09^{+0.08}_{-0.12}$ galaxy with a stellar mass of $\sim10^9 M_\odot$, demonstrating that galaxy build-up was well underway early in the epoch of reionization (EoR) at $z>10$. Targeted spectroscopy of a lensed Lyman break galaxy uncovers the earliest metals known to date up to $z=9.1096\pm0.0006$ by detecting the bright [OIII] 88~$μ$m nebular line, indicating the onset of star formation 250 million years after the Big Bang, i.e., corresponding to a redshift of $z\sim15$. These latest findings lead us to a number of key questions: How and when metal enrichment happened in the EoR? What was the nature of the earliest-epoch star-forming galaxies at $z=10-15$? What was the spatial distribution of such galaxies, and what was the relation to the putative large-scale ionization bubbles during the EoR? What were the dark-halo masses of such earliest-epoch star-forming galaxies? To address all these questions, we need to uncover a statistically large number of $z=10-15$ galaxies in the pre-reionization era. Here we argue two possible pathways: (1) a wide-area, sensitive blind spectroscopic survey of [OIII] 88 $μ$m line-emitting galaxies at submillimeter wavelengths, and (2) an ultra-wide-area, high-cadence photometric survey of transient sources at radio-to-(sub)millimeter wavelengths, together with the immediate follow-up spectroscopy with an ultra-wide-band spectrograph, to catch the pop-III $γ$-ray bursts.
Black Holes in the Shadow: The Missing High-Ionization Lines in the Earliest JWST AGNs
Università degli Studi di Milano-Bicocca(米兰比可卡大学);Stockholm University(斯德哥尔摩大学);University of Cambridge(剑桥大学);University College London(伦敦大学学院);University of California Santa Cruz(加州大学圣克鲁兹分校)
Probing the \ion{He}{2} re-Ionization ERa via Absorbing \ion{C}{4} Historical Yield (HIERACHY) IV: A complex redshifted absorption system intrinsic to quasar
Probing the He II re-Ionization ERa via Absorbing C IV Historical Yield (HIERACHY) II: Project Design, Current Status, and Examples of Initial Data Products
Quasars and the Intergalactic Medium at Cosmic Dawn
类星体在宇宙黎明提供了强有力的探测宇宙中最早的超大质量黑洞(SMBH)的形成和生长,它们与星系和结构形成的联系,以及星系际介质(IGM)在再电离时期(EoR)的演化。在宇宙历史的头十亿年里,已经发现了数百个类星体,类星体的红移边界扩展到z~7.6。对类星体在宇宙黎明的观测表明:(1)在z>5时,亮类星体的数密度呈指数下降,表明最早的类星体出现在z~10时;它们的平均光谱能量分布没有强烈的演化,表明活动星系核环境的迅速建立。(2)在z>7.5时,已经存在了10亿个太阳质量的黑洞;它们必须在不到7亿年的时间内形成和生长,通过大量早期黑洞种子与高效和持续的吸积相结合。(3)类星体的快速增长伴随着强烈的恒星形成和反馈活动,在其宿主星系,这表现出不同的形态和动力学性质,与典型的动力学质量低于本地BH/星系标度关系所暗示的。(4)类星体光谱中的HI吸收探测到宇宙再电离的尾端在z~5.3-6,并指出EoR的中点在6.9 < z < 7.6,IGM电离的空间起伏很大。重元素吸收线的观测表明,环银河系介质也经历了其电离结构和金属富集在EoR的演变。
An Ultra-Faint, Chemically Primitive Galaxy Forming in the Reionization Era
Kanazawa University(金泽大学);National Astronomical Observatory of Japan(日本国立天文台);The University of Tokyo(东京大学);SOKENDAI (The Graduate University for Advanced Studies)(综合研究大学院大学);Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo(东京大学宇宙物质量子研究所(WPI));Istituto Nazionale di Astrofisica (INAF)(意大利国家天体物理研究所);University of Cambridge(剑桥大学)
The Spitzer/IRAC Legacy over the GOODS Fields: Full-Depth 3.6, 4.5, 5.8 and 8.0um Mosaics and Photometry for > 9000 Galaxies at z~3.5-10 from the GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS)
High Equivalent Width of Hα+[N II] Emission in z~8 Lyman-break Galaxies from IRAC 5.8μm Observations: Evidence for Efficient Lyman-continuum Photon production in the Epoch of Re-ionization
High-ionization coronal lines trace quasar-like activity in recently quenched galaxies at high redshift
Cosmic Dawn Center (DAWN)(宇宙黎明中心);DTU Space, Technical University of Denmark(丹麦技术大学空间科学部);École Polytechnique Fédérale de Lausanne (EPFL)(洛桑联邦理工学院);INAF – Astronomical Observatory of Trieste(意大利国家天体物理研究所的里雅斯特天文台);IFPU – Institute for Fundamental Physics of the Universe(宇宙基础物理研究所)
JWST absorption line spectroscopy with SPURS: ISM covering fractions and kinematics in individual galaxies at $z=5-9$
The Observatories of the Carnegie Institution for Science(卡内基科学研究所天文台);Cosmic Dawn Center (DAWN)(宇宙黎明中心);Niels Bohr Institute, University of Copenhagen(哥本哈根大学尼尔斯·玻尔研究所);Department of Astronomy, University of California, Berkeley(加州大学伯克利分校天文学系);Department of Physics and Astronomy, University of California, Davis(加州大学戴维斯分校物理与天文学系);Kavli Institute for Cosmology, University of Cambridge(剑桥大学卡弗里宇宙学研究所);Cavendish Laboratory, University of Cambridge(剑桥大学卡文迪许实验室);Instituto de Estudios Astrofícos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales(迭戈·波特莱斯大学工程与科学学院天体物理研究所);Millenium Nucleus for Galaxies (MINGAL)(星系千年核心(MINGAL));Instituto de Astrofísica, Facultad de Física, Pontificia Univers(宗座大学物理学院天体物理研究所)
Prospects for Observing Galaxy Spectral Energy Distribution from the Radio to the far-Infrared in the Era of Next-Generation Radio Telescopes
National Radio Astronomy Observatory(美国国家射电天文台);Department of Astronomy, University of Virginia(弗吉尼亚大学天文学系);Department of Physics, Northeastern University(东北大学物理系);Department of Physics, Cornell University(康奈尔大学物理系);Eureka Scientific(尤里卡科学公司);Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México(墨西哥国立自治大学无线电天文学与天体物理学研究所);Space Telescope Science Institute(太空望远镜科学研究所);Department of Physics, University of California, Santa Barbara(加州大学圣塔芭芭拉分校物理系);Department of Astronomy, University of Massachusetts, Amherst(马萨诸塞大学阿默斯特分校天文学系)
The JWST and ALMA view of local dwarf Pox 186: Evidence of stripped binaries driving a hard radiation field and little cold molecular gas resulting in high star-formation efficiency
AURA for European Space Agency (ESA), ESA Office, Space Telescope Science Institute(美国大学研究协会(为欧洲空间局)、欧洲空间局办公室、太空望远镜科学研究所);Astrophysics Research Institute, Liverpool John Moores University(利物浦约翰摩尔斯大学天体物理研究所);Space Telescope Science Institute(太空望远镜科学研究所);Centro de Astrobiología (CAB), CSIC-INTA(天文生物学中心(CAB),西班牙国家科学技术研究委员会-国家航空航天技术研究所);Cosmic Dawn Center (DAWN)(宇宙黎明中心);AIM, CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, Sorbonne Paris Cité(天体物理学与图像实验室,法国原子能和替代能源委员会,法国国家科学研究中心,巴黎萨克雷大学,巴黎第七大学,索邦巴黎城市大学);Stockholm University(斯德哥尔摩大学)
Photometric identification and MMT spectroscopy of new extremely metal-poor galaxies: towards a better understanding of young stellar populations at low metallicity
极贫金属恒星形成星系(XMP)是我们唯一的实验室之一,用于研究我们预计在早期遇到的低金属量恒星。但随着我们对$z>6$宇宙的理解不断加深,我们已经清楚地看到,大多数已知的100 Mpc以内的XMP都拥有比再电离时代的XMP明显更不突出的大质量恒星群,这严重限制了它们作为解释最高红移处光谱特征的试验台的实用性。在这里,我们提出了一个新的光度选择技术,旨在确定附近的XMP占主导地位的年轻恒星星族的预期在再电离时代。我们应用我们的技术来发现候选XMP在SDSS成像的幅度$16<i'<23$,扩展显着低于SDSS光谱调查的完整性限制。MMT的光谱观测证实,我们观察到的53个均匀贫金属和高比恒星形成率的目标中有32个具有气相氧丰度$12+\log\mathrm{O/H}<7.7$($Z/Z_\odot<0.1$),包括已知金属丰度最低的星系$Z/Z_\odot<0.05$中的两个。我们的观察揭示了新的光到长期以来的神秘的He II发射在恒星形成的星系:我们发现,He II $λ4686$高电离发射线的等效宽度不缩放与H $β$在我们的样本,这表明,二进制演化或其他过程的$>10$ Myr时间尺度上的贡献很大的$\mathrm{He^+}$电离光子预算在这个金属度制度。将这种选择技术与深光谱学相结合,应用于LSST等下一代光度测量,最终可能为缺乏金属的大质量恒星的经验理解提供基础。
Chemical Complexity in the Early Stages of Star Formation in the SKAO Era
Leiden University(莱顿大学);CNRS, IRAP(法国国家科学研究中心,天体物理研究所);University of Vienna(维也纳大学);Max Planck Institute for Extraterrestrial Physics(马克斯·普朗克地外物理学研究所);CNRS, IPAG(法国国家科学研究中心,格勒诺布尔行星与大气物理实验室);University of Leeds(利兹大学);Tata Institute of Fundamental Research(塔塔基础研究院);University of Bern(伯尔尼大学);National Institute of Science Education and Research(国家科学教育与研究学院);Homi Bhabha National Institute(霍米·巴哈国家研究所);Midnapore City College(金达普城市学院)
本文探讨SKAO(特别是SKA-Mid Band 5)如何通过高灵敏度射电观测,揭示恒星形成早期阶段的前生物分子化学复杂性,为行星系统化学继承提供新见解。