collaborators

18 papers

astro-ph.GA2026

ATLAS. III. Dust Around Little Red Dots: Hydrogen Line Ratios beyond Dust-free Non-Case B Models

Tomokazu Kiyota, Masami Ouchi, Hiroto Yanagisawa +7

We investigate broad hydrogen line ratios in little red dots (LRDs) using five high-redshift () sources from JWST/NIRSpec medium/high-resolution spectra in the DAWN JWST Archi…

astro-ph.GA2026

ATLAS. II. Extremely High Incidence of Balmer Line Absorption with Predominant Blueshifts in LRDs: Statistical Insights through Comparison with Type 1 AGNs

Hiroto Yanagisawa, Masami Ouchi, Tomokazu Kiyota +6

We present the statistical properties of H and H line absorption in little red dots (LRDs) at --7.2 using archival JWST/NIRSpec spectra from the DAWN JWST Archi…

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.GA2026

A Scaling Relation of LRDs between Broad H and Bolometric Luminosities: Enhanced Broad H Emission Relative to Low- Type 1 AGN

Hiroto Yanagisawa, Masami Ouchi, Tomokazu Kiyota +6

We investigate the demography of little red dots (LRDs) using 37 objects at - with JWST/NIRSpec PRISM and grating spectra compiled from various JWST programs. We focus o…

astro-ph.GA2026

Assessing the Impact of Source Confusion for GREX-PLUS based on Deep JWST NIRCam Imaging

Yoshiaki Ono, Akio K. Inoue, Yuma Sugahara +9

We investigate the effects of source confusion expected in observations with GREX-PLUS, a JAXA L-class space infrared telescope mission candidate with a wide-field infrared camera…

astro-ph.GA2026

DREAMS. JWST Spectroscopy of a Galaxy with an ALMA Dust Continuum Detection: Early Dust, Very High , and a Multi-wavelength [OIII] Ratio Discrepancy

Kana Takechi, Masami Ouchi, Kimihiko Nakajima +10

We present a deep DREAMS JWST/NIRSpec MSA medium-grating spectrum of MACS0416-Y1, a galaxy at with the highest-redshift ALMA dust continuum detection to date, in order to…