Yi Xu

activity

20212026

most citedEMPRESS. 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

104 citations · 426 across the 35 of their papers we have counts for

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Showing 2022Show all

3 papers · 1 filter

astro-ph.GA2022★ 104 cited

EMPRESS. V. Metallicity Diagnostics of Galaxies over 12+log(O/H)=~6.9-8.9 Established by a Local Galaxy Census: Preparing for JWST Spectroscopy

Kimihiko Nakajima, Masami Ouchi, Yi Xu +13

We present optical-line gas metallicity diagnostics established by the combination of local SDSS galaxies and the largest compilation of extremely metal-poor galaxies (EMPGs) inclu…

astro-ph.GA2022

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 ( $0.016 - 0.098 Z_{⊙}$ ) and low stellar masses ( $1 0^{4.7} - 1 0^{7.6} M_{⊙}$ ). Tak…

astro-ph.CO2022★ 104 cited

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 $Y_{P}$ is a powerful probe of cosmology. Currently, $Y_{P}$ is best determined by observations of metal-poor galaxies, while there are on…