Primordial Rotating Disk Composed of $\geq$15 Dense Star-Forming Clumps at Cosmic Dawn
S. Fujimoto, M. Ouchi, K. Kohno, F. Valentino, C. Giménez-Arteaga, G. B. Brammer, L. J. Furtak, M. Kohandel, M. Oguri, A. Pallottini, J. Richard, A. Zitrin, F. … 展开作者
S. Fujimoto, M. Ouchi, K. Kohno, F. Valentino, C. Giménez-Arteaga, G. B. Brammer, L. J. Furtak, M. Kohandel, M. Oguri, A. Pallottini, J. Richard, A. Zitrin, F. E. Bauer, M. Boylan-Kolchin, M. Dessauges-Zavadsky, E. Egami, S. L. Finkelstein, Z. Ma, I. Smail, D. Watson, T. A. Hutchison, J. R. Rigby, B. D. Welch, Y. Ao, L. D. Bradley, G. B. Caminha, K. I. Caputi, D. Espada, R. Endsley, Y. Fudamoto, J. González-López, B. Hatsukade, A. M. Koekemoer, V. Kokorev, N. Laporte, M. Lee, G. E. Magdis, Y. Ono, F. Rizzo, T. Shibuya, K. Shimasaku, F. Sun, S. Toft, H. Umehata, T. Wang, H. Yajima
备注:
Nature Astronomy in press. See also the companion papers on arXiv. Valentino+2024: arXiv:2402.17845 Giménez-Arteaga+2024: arXiv:2402.17875
Early galaxy formation, initiated by the dark matter and gas assembly, evolves through frequent mergers and feedback processes into dynamically hot, chaotic structures. In contrast, dynamically cold, smooth rotating disks have been observed in massive evolved galaxies merely 1.4 billion years after the Big Bang, suggesting rapid morphological and dynamical evolution in the early Universe. Probing this evolution mechanism necessitates studies of young galaxies, yet efforts have been hindered by observational limitations in both sensitivity and spatial resolution. Here we report high-resolution observations of a strongly lensed and quintuply imaged, low-luminosity, young galaxy at $z=6.072$ (dubbed the Cosmic Grapes), 930 million years after the Big Bang. Magnified by gravitational lensing, the galaxy is resolved into at least 15 individual star-forming clumps with effective radii of $r_{\rm e}\simeq$ 10--60 parsec (pc), which dominate $\simeq$ 70\% of the galaxy's total flux. The cool gas emission unveils a smooth, underlying rotating disk characterized by a high rotational-to-random motion ratio and a gravitationally unstable state (Toomre $Q \simeq$ 0.2--0.3), with high surface gas densities comparable to local dusty starbursts with $\simeq10^{3-5}$ $M_{\odot}$/pc$^{2}$. These gas properties suggest that the numerous star-forming clumps are formed through disk instabilities with weak feedback effects. The clumpiness of the Cosmic Grapes significantly exceeds that of galaxies at later epochs and the predictions from current simulations for early galaxies. Our findings shed new light on internal galaxy substructures and their relation to the underlying dynamics and feedback mechanisms at play during their early formation phases, potentially explaining the high abundance of bright galaxies observed in the early Universe and the dark matter core-cusp problem.
Ultraviolet photon production rates of the first stars: Impact on the He II $λ$ 1640 Å emission line from primordial star clusters and the 21-cm signal from cosmic dawn
Uppsala University(乌普萨拉大学);University of Cambridge(剑桥大学);Indian Institute of Technology Indore(印度理工学院印多尔分校)
研究第一颗恒星的紫外光子产率及其对He II 1640 Å发射线和宇宙黎明时期21厘米信号的影响,探讨初始质量和旋转对光子产率的影响。
High-Redshift Signatures from the Cosmic Dawn and the Epoch of Reionization
Tel Aviv University(特拉维夫大学);University of Maryland, College Park(马里兰大学帕克分校);New York University(纽约大学);Jadavpur University(贾达普大学);Stockholm University(斯德哥尔摩大学);University of Groningen(格罗宁根大学);University of Sussex(萨塞克斯大学);Guangxi University(广西大学);Tsinghua University(清华大学);University of Cambridge(剑桥大学);The University of Texas at Austin(德克萨斯大学奥斯汀分校);University of Zurich(苏黎世大学);Chinese Academy of Sciences(中国科学院);Northeastern University(东北大学);Tata Institute of Fundamental Research(塔塔基础研究所);Oberlin College(欧柏林学院);University of Toronto(多伦多大学)
Earliest quasars at the cosmic dawn are powered by mass accretion onto supermassive black holes of a billion solar masses. Massive black hole seeds forming through the direct collapse mechanism are considered the most promising candidates but how do they grow and co-evolve with their host galaxies at early cosmic times remains unknown. We here present results from a cosmological radiation hydrodynamical simulation including self-consistent modeling of both Pop III and Pop II star formation, their radiative and supernova feedback in the host galaxy along with X-ray feedback from an accreting ma…
Using a large sample of sub-L$_*$ galaxies, with similar UV magnitudes, M$_{\rm UV}\simeq -19$ at $z\simeq6$, extracted from the FirstLight simulations, we show the diversity of galaxies at the end of the reionization epoch. We find a factor $\sim$40 variation in the specific star-formation rate (sSFR). This drives a $\sim$1 dex range in equivalent width of the [OIII]$λ$5007 line. Variations in nebular metallicity and ionization parameter within HII regions lead to a scatter in the equivalent widths and [OIII]/H$α$ line ratio at a fixed sSFR. [OIII]-bright emitters ([OIII]/H$α$>1) have higher …
Turbulence in Primordial Dark Matter Halos and Its Impact on the First Star Formation
Institute of Astronomy and Astrophysics, Academia Sinica(中央研究院天文及天文物理研究所);Department of Physics, National Taiwan University(国立台湾大学物理系);Department of Physics and Astronomy, University of California, Riverside(加州大学河滨分校物理与天文学系);Heidelberg Institute for Theoretical Studies(海德堡理论研究所)
Properties of the first generation of stars (Pop III), such as their initial mass function (IMF), are poorly constrained by observations and have yet to converge between simulations. The cosmological 21-cm signal of neutral hydrogen is predicted to be sensitive to Lyman-band photons produced by these stars, thus providing a unique way to probe the first stellar population. In this paper, we investigate the impacts of the Pop III IMF on the cosmic dawn 21-cm signal via the Wouthuysen-Field effect, Lyman-Werner feedback, Ly-alpha heating, and CMB heating. We calculate the emission spectra of sta…
The origin and fate of the most extended extragalactic neutral cloud known in the local Universe, the Leo ring, is still debated 38 years after its discovery. Its existence is alternatively attributed to leftover primordial gas with some low level of metal pollution versus enriched gas stripped during a galaxy-galaxy encounter. Taking advantage of MUSE (Multi Unit Spectroscopic Explorer) operating at the VLT, we performed optical integral field spectroscopy of 3 HI clumps in the Leo ring where ultraviolet continuum emission has been found. We detected, for the first time, ionized hydrogen in t…
Pressure-driven fragmentation of clouds at high redshift
一颗总金属丰度为$\le 10^{-5}$ Z $_\odot$的超贫金属恒星的发现,激发了人们对这类天体如何由一颗超新星污染的原始气体形成的新研究。在本文中,我们提出了一个激波云模型,它模拟了一个超新星遗迹与云相互作用在一个无金属的环境中在红移$z=10$。前超新星的条件被认为是,其中包括一个多相中性介质和H II区域。一个小的致密团块($n=100$ cm $^{-3}$),距离40 M $_\odot$无金属恒星40 pc,嵌入在$n=10$ cm $^{-3}$周围云中。超新星遗迹的演化(爆炸能量$10^{52}$ erg)及其随后与致密团块的相互作用进行了研究。这是第一个研究,包括一个全面的处理非平衡化学和相关的辐射冷却,发生在所有阶段的冲击云模型。我们已经包括了一个原始化学网络,覆盖了温度范围$10-10^9$ K,并耦合到原子和分子冷却的热模型。我们发现$\times10^{3}$密度增强的团块(即最大密度$\sim 78000$ cm $^{-3}$)在此无金属模型。这与考虑太阳金属丰度气体与平衡冷却功能的银河系激波云模型是一致的。尽管有这种强烈的压缩,云并没有变得重力不稳定。我们发现,在这里模拟的小的云被破坏的冲击速度$\gtrsim 50\,$公里的$^{-1}$,并没有显着影响的冲击速度$\lesssim 30\,$公里的$^{-1}$。要使这样的云坍缩,需要…
Planet Formation at Cosmic Dawn: Planetesimals in H$_2$O-Rich Disks Around Low-Mass Stars
Institut fur Astro- und Teilchenphysik, Universitaat Innsbruck(因斯布鲁克大学天体与粒子物理研究所);Research Institute of Physics, Southern Federal University(南联邦大学物理研究所);Institute of Cosmology and Gravitation, Portsmouth University(朴茨茅斯宇宙学与引力研究所);Physics Department, College of Science, United Arab Emirates University(阿拉伯联合酋长国大学理学院物理系);National Institute of Technology, Kochi College(高知技术学院);Department of Physics, Graduate School of Science, Kyoto University(京都大学理学研究科物理系);Center for Astrophysics, Harvard and Smithsonian(哈佛史密森尼天体物理中心)
The ALMA Survey of Star Formation and Evolution in Massive Protoclusters with Blue Profiles (ASSEMBLE): Core Growth, Cluster Contraction, and Primordial Mass Segregation
Mapping Cosmic Dawn with 21-cm tomography offers an exciting new window into the era of primordial star formation. However, self-consistent implementation of both the process of star formation and the related 21-cm signal is challenging, due to the multi-scale nature of the problem. In this study, we develop a flexible semi-analytical model to follow the formation of the first stars and the process of gradual transition from primordial to metal-enriched star formation. For this transition we use different in scenarios with varying time-delays (or recovery times) between the first supernovae an…
We present the hypothesis that some of ring galaxies were formed by relic magnetic torus - shaped wormholes. In the primordial plasma before the recombination magnetic fields of wormholes trap baryons whose energy is smaller than a threshold energy. They work as the Maxwell's demons collecting baryons from the nearest (horizon size) region and thus forming clumps of baryonic matter which have the same torus-like shapes as wormhole throats. Such clumps may serve as seeds for the formation of ring galaxies and smaller objects having the ring form. Upon the recombination torus-like clumps may dec…
Modelling the gas kinematics of an atypical Lyman-alpha emitting compact dwarf galaxy
恒星形成致密矮星系(CDG)类似于宇宙中第一个星系的预期原始条件,是测试原始星系形成和演化模型的最佳系统。在这里,我们报告这样的CDG之一,Tololo 1214-277,它提出了一个广泛的,单峰的,高度对称的赖氨酸$α$发射线,至今逃避理论解释。在本文中,我们第一次重现这些线功能与两个不同的物理动机的运动学模型:一个星际介质组成的外流团块与随机运动和均匀的气体球进行固体旋转。多相模型需要$54.3\pm 0.6$ km s $^{-1}$的块速度色散,流出$54.3\pm 5.1$ km s $^{-1}$,而整体旋转速度被约束为$348^{+75}_{-48}$ km s $^{-1}$。我们认为,从多相模型的结果提供了一个正确的解释数据。在这种情况下,团块的速度色散意味着动力学质量为$2\times 10^{9}$ M $_{\odot}$,是重子质量的10倍。如果Tololo 1214-277未来的运动学图证实了多相模型所建议的速度,它将提供额外的支持,以期望这样的运动学状态在原始星系,打开机会,使用本文提出的模型和方法,以限制在Ly- $α$发射星系的早期世代的恒星形成和反馈的物理。
The SPT0311-58 system at z=6.900 is an extremely massive structure within the reionization epoch, and offers a chance to understand the formation of galaxies in an extreme peak in the primordial density field. We present 70mas Atacama Large Millimeter/submillimeter Array observations of the dust continuum and CII 158um emission in the central pair of galaxies and reach physical resolution ~100-350pc, among the most detailed views of any reionization-era system to date. The observations resolve the source into at least a dozen kiloparsec-size clumps. The global kinematics and high turbulent vel…
The Impact of Fuzzy Dark Matter Dynamics on the Accumulation and Fragmentation of Primordial Gas
Fakultät für Physik, Universität Bielefeld(比勒费尔德大学物理学院);Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik(海德堡大学天文学中心理论天体物理研究所);Universität Heidelberg, Interdisziplinäres Zentrum für Wissenschaftliches Rechnen(海德堡大学科学计算跨学科中心)
The mass segregation of stellar clusters could be primordial rather than dynamical. Despite the abundance of studies of mass segregation for stellar clusters, those for stellar progenitors are still scarce, so the question on the origin and evolution of mass segregation is still open. Our goal is to characterize the structure of the NGC 2264 molecular cloud and compare the populations of clumps and young stellar objects (YSOs) in this region whose rich YSO population has shown evidence of sequential star formation. We separated the Herschel column density map of NGC 2264 in three subregions an…
Star cluster formation from turbulent clumps. V. Stellar clustering around massive stars
University of Virginia(弗吉尼亚大学);Virginia Institute for Theoretical Astronomy, University of Virginia(弗吉尼亚理论天文学研究所,弗吉尼亚大学);University of Texas at Austin(德克萨斯大学奥斯汀分校);McMaster University(麦克马斯特大学);Chalmers University of Technology(查尔姆斯理工大学)
Molecular hydrogen allows cooling in primordial gas, facilitating its collapse into Population III stars within primordial halos. Lyman-Werner (LW) radiation from these stars can escape the halo and delay further star formation by destroying H$_2$ in other halos. As cosmological simulations show that increasing the background LW field strength increases the average halo mass required for star formation, we perform follow-up simulations of selected halos to investigate the knock-on effects this has on the Population III IMF. We follow 5 halos for each of the $J_{21}$ = 0, 0.01 and 0.1 LW field …