(abridged) A scenario for the formation of multiple co-eval populations separated in age by about 1 Myr in very young clusters (VYCs, ages less than 10 Myr) and with masses in the range 600-20000 Msun is outlined. It rests upon a converging inflow of molecular gas building up a first population of pre-main sequence stars. The associated just-formed O stars ionise the inflow and suppress star formation in the embedded cluster. However, they typically eject each other out of the embedded cluster within 10^6 yr, that is before the molecular cloud filament can be ionised entirely. The inflow of molecular gas can then resume forming a second population. This sequence of events can be repeated multiply. This model is applied to the Orion Nebula Cluster (ONC), in which three well-separated pre-main sequences in the color-magnitude diagram of the cluster have recently been discovered. The mass-inflow history is constrained using this model and the number of OB stars ejected from each population are estimated for verification using Gaia data. As a consequence of the proposed model, the three runaway O star systems, AE Aur, mu Col and iota Ori, are considered as significant observational evidence for stellar-dynamical ejections of massive stars from the oldest population in the ONC.
In recent years, several analytic models have demonstrated that simple assumptions about halo growth and feedback-regulated star formation can match the (limited) existing observational data on galaxies at z>6. By extending such models, we demonstrate that imposing a time delay on stellar feedback (as inevitably occurs in the case of supernova explosions) induces burstiness in small galaxies. Although supernova progenitors have short lifetimes (~5-30 Myr), the delay exceeds the dynamical time of galaxies at such high redshifts. As a result, star formation proceeds unimpeded by feedback for sev…
We characterize the stellar and gas volume density, potential, and gravitational field profiles in the central $\sim$ 0.5 pc of the Orion Nebula Cluster (ONC), the nearest embedded star cluster (or rather, proto-cluster) hosting massive star formation available for detailed observational scrutiny. We find that the stellar volume density is well characterized by a Plummer profile $ρ_{stars}(r) = 5755\,{\rm M}_{\odot}\,{\rm pc}^{-3}\,(1+(r/a)^2)^{-5/2}$, where $a = 0.36$ pc. The gas density follows a cylindrical power law $ρ_{gas}(R) = 25.9\,{\rm M}_{\odot}\,{\rm pc}^{-3}\,(R/{\rm pc})^{-1.775}$…
We present a survey for the tightest visual binaries among 0.3-2 Msun members the Orion Nebula Cluster (ONC). Among 42 targets, we discovered 13 new 0.025-0.15" companions. Accounting for the Branch bias, we find a companion star fraction (CSF) in the 10-60 au range of 21+8/-5%, consistent with that observed in other star-forming regions (SFRs) and twice as high as among field stars; this excess is found with a high level of confidence. Since our sample is dominated by disk-bearing targets, this indicates that disk disruption by close binaries is inefficient, or has not yet taken place, in the…
RIGEL: Feedback-regulated cloud-scale star formation efficiency in a simulated dwarf galaxy merger
Tsinghua University（清华大学）；University of Bologna（博洛尼亚大学）；INAF, Astrophysics and Space Science Observatory Bologna（意大利国家天体物理研究所博洛尼亚天文与空间科学观测站）；Institute for Advanced Study, Tsinghua University（清华大学高等研究院）；Universität Heidelberg（海德堡大学）；The University of Texas at Dallas（德克萨斯大学达拉斯分校）；York University（约克大学）；Columbia University（哥伦比亚大学）
An emerging baryon cycle in a galaxy 500 million years after the Big Bang
School of Astronomy and Space Science, University of Chinese Academy of Sciences (UCAS)（中国科学院大学天文与空间科学学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University（北京师范大学天文与前沿科学研究院）；Department of Astronomy, Tsinghua University（清华大学天文系）；School of Astronomy and Space Science, Nanjing University（南京大学天文与空间科学学院）；Department of Astronomy, School of Physics, Peking University（北京大学物理学院天文系）；Kavli Institute for Astronomy and Astrophysics, Peking University（北京大学科维理天文与天体物理研究所）
Imladris: a detailed and flexible model for galaxy simulations with individual stars
Max-Planck-Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；Universität Heidelberg, Zentrum für Astronomie（海德堡大学天文中心）；Max-Planck-Institut für Astronomie（马克斯·普朗克天文学研究所）
Bright Galaxies at Cosmic Dawn: A Cloud-Scale Star Formation Model Unifying Variable SFE, IMFs, and Stochasticity
Max Planck Institut für Astrophysik（马克斯·普朗克天体物理学研究所）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；Cosmic Dawn Center (DAWN)（宇宙黎明中心）；Department of Astrophysics, University of Vienna（维也纳大学天体物理系）
From short-lived to long-lived clouds: impact of star formation models on giant molecular cloud evolution in simulations of an NGC 300-like galaxy
Yonsei University（延世大学）；Korea Astronomy and Space Science Institute（韩国天体物理与空间科学研究所）；Korea Institute for Advanced Study（韩国高等研究院）；University of Chicago（芝加哥大学）；Centre de Recherche Astrophysique de Lyon UMR5574, Univ Lyon, Univ Lyon1, Ens de Lyon（里昂天体物理研究中心）
The Nearby Star Formation and Supernova Histories Reconstructed from Young Star Clusters
Center for Astrophysics — Harvard & Smithsonian（天体物理中心——哈佛与史密森尼学会）；Department of Astrophysics, University of Vienna（维也纳大学天体物理学系）；Department of Physics, University of Wisconsin–Whitewater（威斯康星大学惠特沃分校物理系）
Primordial Black Holes as Seeds for Extremely Overmassive AGN Observed by JWST
University of Texas at Austin（德克萨斯大学奥斯汀分校）；Weinberg Institute for Theoretical Physics, Texas Center for Cosmology and Astroparticle Physics, University of Texas at Austin（德克萨斯大学奥斯汀分校温伯格理论物理研究所、德州宇宙学与天体粒子物理中心）；Institute of Astronomy, University of Cambridge（剑桥大学天文研究所）；Universität Heidelberg, Zentrum fur Astronomie, Institut für Theoretische Astrophysik（海德堡大学天文学中心理论天体物理研究所）；Department of Astronomy, University of Texas at Austin（德克萨斯大学奥斯汀分校天文学系）；Max-Planck-Institut für Physik（马克斯·普朗克物理研究所）；Arnold Sommerfeld Center, Ludwig-Maximilians-Universität（慕尼黑大学阿诺德·索末菲理论物理中心）
