42 citations · 49 across the 11 of their papers we have counts for
13 papers · 1 filter
SIRIUS Project: Dynamical Evolution of Primordial Binaries during Star Cluster Formation
Naoto Harada, Michiko S. Fujii, Takayuki R. Saitoh +1
Binary populations are closely linked to the star formation process; however, their primordial properties can be changed by subsequent dynamical interactions within their natal clu…
SIRIUS: The relation between the diversity of dwarf galaxies and their formation histories
Chi-Hong Lin, Michiko S Fujii, Takayuki R Saitoh +1
Low-mass dwarf galaxies () are fundamental cosmological building blocks, yet the physical processes driving their structural diversity remain…
SIRIUS: Dark matter cusp evolution in dense dwarf galaxies
Katsuhiro Kaneko, Takayuki R. Saitoh, Yutaka Hirai +1
Dwarf galaxies have a wide variety of structures, such as dark matter (DM) distribution, stellar-to-halo mass ratio, and stellar density. Recent high-resolution simulations have sh…
Nitrogen enhancement of GN-z11 by metal pollution from supermassive stars
Sho Ebihara, Michiko S. Fujii, Takayuki R. Saitoh +4
Spectroscopic observations by the James Webb Space Telescope (JWST) have revealed young, compact, high-redshift () galaxies with high nitrogen-to-oxygen (N/O) ratios. GN-z11 at…
Bursty star formation, chemical enrichment, and star cluster formation in numerical analogues of GN-z11
Takayuki R. Saitoh, Yutaka Hirai, Michiko S. Fujii +1
The James Webb Space Telescope reveals anomalous nitrogen enrichment (high N/O ratios) in compact, star-forming galaxies, such as GN-z11 at . The origin of this chemical s…
The First Star-by-star -body/Hydrodynamics Simulation of Our Galaxy Coupling with a Surrogate Model
Keiya Hirashima, Michiko S. Fujii, Takayuki R. Saitoh +9
A major goal of computational astrophysics is to simulate the Milky Way Galaxy with sufficient resolution down to individual stars. However, the scaling fails due to some small-sca…
Dynamical Mechanism of Episodic Gas Accretion to the Central Region of Spiral Galaxies
Naomichi Yutani, Nozomu Kawakatu, Takayuki Saitoh +1
We performed \textit{N}-body/SPH simulations of isolated spiral galaxies with various bulge-to-disk mass ratios () from 0.02 to 0.2 to investigate mass…
SIRIUS: Identifying Metal-poor Stars Enriched by a Single Supernova in a Dwarf Galaxy Cosmological Zoom-in Simulation Resolving Individual Massive Stars
Yutaka Hirai, Takayuki R. Saitoh, Michiko S. Fujii +2
Metal-poor stars enriched by a single supernova (mono-enriched stars) are direct proof (and provide valuable probes) of supernova nucleosynthesis. Photometric and spectroscopic obs…
ASURA-FDPS-ML: Star-by-star Galaxy Simulations Accelerated by Surrogate Modeling for Supernova Feedback
Keiya Hirashima, Kana Moriwaki, Michiko S. Fujii +5
We introduce new high-resolution galaxy simulations accelerated by a surrogate model that reduces the computation cost by approximately 75 percent. Massive stars with a Zero Age Ma…
The -Process Alliance: Enrichment of -process Elements in a Simulated Milky Way-like Galaxy
Yutaka Hirai, Timothy C. Beers, Young Sun Lee +11
We study the formation of stars with varying amounts of heavy elements synthesized by the rapid neutron-capture process (-process) based on our detailed cosmological zoom-in sim…
Simulations predict intermediate-mass black hole formation in globular clusters
Michiko S. Fujii, Long Wang, Ataru Tanikawa +2
Intermediate-mass black holes (IMBHs) are those between 100 and 10 solar masses (); their formation process is debated. One possible origin is the growth of less mas…
Chemo-dynamical Evolution of Simulated Satellites for a Milky Way-like Galaxy
Yutaka Hirai, Evan N. Kirby, Masashi Chiba +5
The chemical abundances of Milky Way's satellites reflect their star formation histories (SFHs), yet, due to the difficulty of determining the ages of old stars, the SFHs of most s…
Probing Chemical Enrichment in Extremely Metal-Poor Galaxies
Keita Fukushima, Kentaro Nagamine, Akinori Matsumoto +4
The chemical composition of galaxies offers vital insights into their formation and evolution. In particular, the relationship between helium abundance (He/H) and metallicity serve…