193 citations · 859 across the 24 of their papers we have counts for
25 papers
Internal Radiative Feedback Triggers Global Collapse and Direct-Collapse Black Hole Formation in Metal-free Atomic-Cooling Haloes
Masaki Kiyuna, Sunmyon Chon, Kazuyuki Omukai +1
The formation of heavy seed black holes from the collapse of supermassive stars (SMSs) is a promising pathway to the supermassive black holes (SMBHs). In the conventional direct-co…
Formation of Heavy Seed Black Holes and Little Red Dots-like Compact Clusters in Metal-enriched Star-forming Regions
Sunmyon Chon, Shingo Hirano, Ke-Jung Chen +1
The origin of supermassive black holes (SMBHs) in the early Universe remains uncertain. While the classical direct-collapse scenario requires pristine gas exposed to intense Lyman-…
Formation of massive multiple-star systems: early migration and mergers
Sunmyon Chon, Alejandro Vigna-Gómez
Massive stars are often found in multiple systems, yet how binary-star systems with very close separations ( au) assemble remains unresolved. We investigate the formation…
Overmassive black holes and little red dots naturally form in simulations
Sunmyon Chon, Shingo Hirano, Tomoaki Ishiyama +2
The origin of supermassive black holes (SMBHs) remains a long-standing problem in astrophysics. Recent JWST observations reveal an unexpectedly abundant population of overmassive b…
Growth of Metal-Enriched Supermassive Stars by Accretion and Collisions
Devesh Nandal, Sunmyon Chon
Supermassive stars (SMSs) are candidate progenitors of massive black hole seeds and may contribute to anomalous abundance patterns in high-redshift galaxies and globular clusters.…
Formation of supermassive stars and dense star clusters in metal-poor clouds exposed to strong FUV radiation
Sunmyon Chon, Kazuyuki Omukai
The direct collapse scenario, which predicts the formation of supermassive stars (SMSs) as precursors to supermassive black holes (SMBHs), has been explored primarily under the ass…
Gravitational collapse at low to moderate Mach numbers: The relationship between star formation efficiency and the fraction of mass in the massive object
Jorge Saavedra-Bastidas, Dominik R. G. Schleicher, Ralf S. Klessen +7
The formation of massive objects via gravitational collapse is relevant both for explaining the origin of the first supermassive black holes and in the context of massive star form…
Sequential formation of supermassive stars and heavy seed BHs through the interplay of cosmological cold accretion and stellar radiative feedback
Masaki Kiyuna, Takashi Hosokawa, Sunmyon Chon
Supermassive stars (SMSs) and heavy seed black holes, as their remnants, are promising candidates for Supermassive Black Hole (SMBH) progenitors, especially for ones observed in th…
Impact of radiative feedback on the initial mass function of metal-poor stars
Sunmyon Chon, Takashi Hosokawa, Kazuyuki Omukai +1
The stellar initial mass function (IMF) in the early universe is essential to understand the formation of ancient galaxies. To this end, we conduct a series of long-term radiation…
Exploring the nature of UV-bright galaxies detected by JWST: star formation, black hole accretion, or a non-universal IMF?
Alessandro Trinca, Raffaella Schneider, Rosa Valiante +4
We use the Cosmic Archaeology Tool (CAT) semi-analytical model to explore the contribution of Population (Pop) III/II stars and active galactic nuclei (AGNs) to the galaxy UV lumin…
Direct-collapse black hole formation induced by internal radiation of host halos
Gen Chiaki, Sunmyon Chon, Kazuyuki Omukai +3
We estimate the fraction of halos that host supermassive black holes (SMBHs) forming through the direct collapse (DC) scenario by using cosmological N -body simulations combined wi…
First emergence of cold accretion and supermassive star formation in the early universe
Masaki Kiyuna, Takashi Hosokawa, Sunmyon Chon
We investigate the first emergence of the so-called cold accretion, the accretion flows deeply penetrating a halo, in the early universe with cosmological N-body/SPH simulations. W…
H1821+643: The most X-ray and infrared luminous AGN in the Swift/BAT survey in the process of rapid stellar and supermassive black hole mass assembly
Hikaru Fukuchi, Kohei Ichikawa, Masayuki Akiyama +6
H1821+643 is the most X-ray luminous non-beamed AGN of erg s in the Swift/BAT ultra-hard X-ray survey and it is also a hyper-lumin…
Impact of the cosmic background radiation on the initial mass function of metal-poor stars
Sunmyon Chon, Haruka Ono, Kazuyuki Omukai +1
We study star cluster formation at low metallicities of -- using three-dimensional hydrodynamics simulations. Particular emphasis is put on how the stel…
Light, medium-weight or heavy? The nature of the first supermassive black hole seeds
F. Sassano, R. Schneider, R. Valiante +5
Observations of hyper-luminous quasars at reveal the rapid growth of supermassive black holes (SMBHs ) whose origin is still difficult to explain. Their…
Transition of the initial mass function in the metal-poor environments
Sunmyon Chon, Kazuyuki Omukai, Raffaella Schneider
We study star cluster formation in a low-metallicity environment using three dimensional hydrodynamic simulations. Starting from a turbulent cloud core, we follow the formation and…
Disk fragmentation and intermittent accretion onto supermassive stars
Ryoki Matsukoba, Eduard I. Vorobyov, Kazuyuki Sugimura +3
Supermassive stars (SMSs) with are candidate objects for the origin of supermassive black holes observed at redshift >6. They are supposed to f…
Cosmological DCBH formation sites hostile for their growth
Sunmyon Chon, Takashi Hosokawa, Kazuyuki Omukai
The direct collapse (DC) is a promising mechanism that provides massive seed black holes (BHs) with in the early universe. To study a long-term accretion gr…
Supermassive Star Formation via Super Competitive Accretion in Slightly Metal-enriched Clouds
Sunmyon Chon, Kazuyuki Omukai
Direct collapse black hole (DCBH) formation with mass is a promising scenario for the origin of high-redshift supermassive black holes. It has usually be…
Forming Pop III binaries in self-gravitating disks: how to keep the orbital angular momentum
Sunmyon Chon, Takashi Hosokawa
The disk fragmentation is a possible process leading to the formation of Population III stellar binary systems. However, numerical simulations show diverse fates of the fragments;…
Titans of the Early Universe: The Prato Statement on the Origin of the First Supermassive Black Holes
Tyrone E. Woods, Bhaskar Agarwal, Volker Bromm +30
In recent years, the discovery of massive quasars at z~7 has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Un…
Radiation hydrodynamics simulations of the formation of direct-collapse supermassive stellar systems
Sunmyon Chon, Takashi Hosokawa, Naoki Yoshida
Formation of supermassive stars (SMSs) with mass ~10^4 Msun is a promising pathway to seed the formation of supermassive black holes in the early universe. The so-called direct-col…
The impact of ionizing radiation on the formation of a supermassive star in the early Universe
Sunmyon Chon, Muhammad A. Latif
A massive primordial halo near an intensely star-forming galaxy may collapse into a supermassive star (SMS) and leave a massive black hole seed of about . To invest…
Cosmological Simulations of Early Blackhole Formation: Halo Mergers, Tidal Disruption, and the Conditions for Direct Collapse
Sunmyon Chon, Shingo Hirano, Takashi Hosokawa +1
Gravitational collapse of a massive primordial gas cloud is thought to be a promising path for the formation of supermassive blackholes in the early universe. We study conditions f…