134 citations · 786 across the 21 of their papers we have counts for
21 papers
EMPRESS. X. Spatially resolved mass-metallicity relation in extremely metal-poor galaxies: evidence of episodic star-formation fueled by a metal-poor gas infall
Kimihiko Nakajima, Masami Ouchi, Yuki Isobe +47
Using the Subaru/FOCAS IFU capability, we examine the spatially resolved relationships between gas-phase metallicity, stellar mass, and star-formation rate surface densities (Sigma…
EMPRESS. XIV. Strong High Ionization Lines of Young Galaxies at : Ionizing Spectra Consistent with the Intermediate Mass Black Holes with
Shun Hatano, Masami Ouchi, Hiroya Umeda +16
We present ionizing spectra estimated at 13.6--100 eV for ten dwarf galaxies with strong high ionization lines of He {\sc {ii}}4686 and [Ne {\sc{v}}]3426 ([Ne {\sc{iv}}]24…
EMPRESS. XII. Statistics on the Dynamics and Gas Mass Fraction of Extremely-Metal Poor Galaxies
Yi Xu, Masami Ouchi, Yuki Isobe +49
We present demography of the dynamics and gas-mass fraction of 33 extremely metal-poor galaxies (EMPGs) with metallicities of and low stellar masses of $10^4-…
Dust grain size evolution in local galaxies: a comparison between observations and simulations
M. Relano, I. De Looze, A. Saintonge +13
The evolution of the dust grain size distribution has been studied in recent years with great detail in cosmological hydrodynamical simulations taking into account all the channels…
EMPRESS. IX. Extremely Metal-Poor Galaxies are Very Gas-Rich Dispersion-Dominated Systems: Will JWST Witness Gaseous Turbulent High-z Primordial Galaxies?
Yuki Isobe, Masami Ouchi, Kimihiko Nakajima +49
We present kinematics of 6 local extremely metal-poor galaxies (EMPGs) with low metallicities () and low stellar masses (). Tak…
EMPRESS. VIII. A New Determination of Primordial He Abundance with Extremely Metal-Poor Galaxies: A Suggestion of the Lepton Asymmetry and Implications for the Hubble Tension
Akinori Matsumoto, Masami Ouchi, Kimihiko Nakajima +42
The primordial He abundance is a powerful probe of cosmology. Currently, is best determined by observations of metal-poor galaxies, while there are on…
EMPRESS. VII. Ionizing Spectrum Shapes of Extremely Metal-Poor Galaxies: Uncovering the Origins of Strong HeII and the Impact on Cosmic Reionization
Hiroya Umeda, Masami Ouchi, Kimihiko Nakajima +5
Strong high-ionization lines such as HeII of young galaxies are puzzling at high and low redshift. Although recent studies suggest the existence of non-thermal sources, whether the…
Stellar Initial Mass Function (IMF) Probed with Supernova Rates and Neutrino Background: Cosmic Average IMF Slope is Similar to the Salpeter IMF
Shohei Aoyama, Masami Ouchi, Yuichi Harikane
The stellar initial mass function (IMF) is expressed by with the slope , and known as the poorly-constrained but very important function in studies of star…
Gaia 400,894 QSO constraint on the energy density of low-frequency gravitational waves
Shohei Aoyama, Daisuke Yamauchi, Maresuke Shiraishi +1
Low frequency gravitational waves (GWs) are keys to understanding cosmological inflation and super massive blackhole (SMBH) formation via blackhole mergers, while it is difficult t…
Galaxy simulation with the evolution of grain size distribution
Shohei Aoyama, Hiroyuki Hirashita, Kentaro Nagamine
We compute the evolution of interstellar dust in a hydrodynamic simulation of an isolated disc galaxy. We newly implement the evolution of full grain size distribution by sampling…
Dust scaling relations in a cosmological simulation
Kuan-Chou Hou, Shohei Aoyama, Hiroyuki Hirashita +2
To study the dust evolution in the cosmological structure formation history, we perform a smoothed particle hydrodynamic simulation with a dust enrichment model in a cosmological v…
Remodeling the evolution of grain size distribution in galaxies
Hiroyuki Hirashita, Shohei Aoyama
We revisit the evolution model of grain size distribution in a galaxy for the ultimate purpose of implementing it in hydrodynamical simulations. We simplify the previous model in s…
Comparison of cosmological simulations and deep submillimetre galaxy surveys
Shohei Aoyama, Hiroyuki Hirashita, Chen-Fatt Lim +8
Recent progress in submillimetre surveys by single-dish telescopes allows us to further challenge the consistency between cosmological simulations and observations. In particular,…
Cosmological simulation with dust formation and destruction
Shohei Aoyama, Kuan-Chou Hou, Hiroyuki Hirashita +2
To investigate the evolution of dust in a cosmological volume, we perform hydrodynamic simulations, in which the enrichment of metals and dust is treated self-consistently with sta…
Populating H and CO in galaxy simulation with dust evolution
Li-Hsin Chen, Hiroyuki Hirashita, Kuan-Chou Hou +3
There are two major theoretical issues for the star formation law (the relation between the surface densities of molecular gas and star formation rate on a galaxy scale): (i) At lo…
Evolution of dust extinction curves in galaxy simulation
Kuan-Chou Hou, Hiroyuki Hirashita, Kentaro Nagamine +2
To understand the evolution of extinction curve, we calculate the dust evolution in a galaxy using smoothed particle hydrodynamics simulations incorporating stellar dust production…
Galaxy Simulation with Dust Formation and Destruction
Shohei Aoyama, Kuan-Chou Hou, Ikkoh Shimizu +4
We perform smoothed particle hydrodynamics (SPH) simulations of an isolated galaxy with a new treatment for dust formation and destruction. To this aim, we treat dust and metal pro…
Effects of axions on Nucleosynthesis in massive stars
Shohei Aoyama, Takeru K. Suzuki
We investigate the effect of the axion cooling on the nucleosynthesis in a massive star with by standard stellar evolution calculation. We find that the axion cooling…
Upper limit on the amplitude of gravitational waves around 0.1Hz from the Global Positioning System
Shohei Aoyama, Rina Tazai, Kiyotomo Ichiki
The global positioning system (GPS) is composed of thirty one satellites having atomic clocks with accuracy on board and enables one to calibrate the primary standard fo…
Evolution of perturbations and cosmological constraints in decaying dark matter models with arbitrary decay mass products
Shohei Aoyama, Toyokazu Sekiguchi, Kiyotomo Ichiki +1
Decaying dark matter (DDM) is a candidate which can solve the discrepancies between predictions of the concordance CDM model and observations at small scales such as the number…
Formulation and constraints on decaying dark matter with finite mass daughter particles
Shohei Aoyama, Kiyotomo Ichiki, Daisuke Nitta +1
Decaying dark matter cosmological models have been proposed to remedy the overproduction problem at small scales in the standard cold dark matter paradigm. We consider a decaying d…