activity
20242026
collaborators

5 papers

astro-ph.GA2026

Chemical Abundance Ratios of Nitrogen Rich Galaxies Identified at : Observational Demographics and Models

Kuria Watanabe, Masami Ouchi, Kimihiko Nakajima +13

We present chemical abundance ratios of 8 nitrogen-rich ([N/O]) galaxies at identified by the first 4 years of the JWST observations, and compare these ratios wi…

astro-ph.GA2025

Fe Abundances of Early Galaxies at Derived with Deep JWST Spectra

Minami Nakane, Masami Ouchi, Kimihiko Nakajima +12

We derive Fe-abundance ratios of 7 galaxies at with whose JWST/NIRSpec spectra achieve very high signal-to-noise ratios, , a…

astro-ph.SR2025

Potassium abundances in extremely metal poor stars: Implications for nucleosynthesis in the final stages of massive star evolution

M. N. Ishigaki, N. Tominaga, W. Aoki +5

We present a potassium (K) abundance analysis in extremely metal-poor (EMP) stars based on high-resolution () spectra obtained with the High Dispersion Spectrograph on…

astro-ph.HE2024

Hydrodynamics and Nucleosynthesis of Jet-Driven Supernovae II: Comparisons with Abundances of Extremely Metal-Poor Galaxies and Constraints on Supernova Progenitors

Shing-Chi Leung, Ken'ichi Nomoto

The spectra of several galaxies, including extremely metal-poor galaxies (EMPGs) from the EMPRESS survey, have shown that the abundances of some Si-group elements differ from "sphe…

astro-ph.GA2024

Low [O/Fe] Ratio in a Luminous Galaxy at the Early Cosmic Epoch (): Signature of Short Delay Time or Bright Hypernovae/Pair-Instability Supernovae?

Minami Nakane, Masami Ouchi, Kimihiko Nakajima +12

We present an [O/Fe] ratio of a luminous galaxy GN-z11 at derived with the deep public JWST/NIRSpec data. We fit the medium-resolution grating (G140M, G235M, and G395M) d…