14 papers
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…
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…
VENUS: Strong-lensing model of MACS J1931.8-2635 -- revealing the farthest multiply imaged supernova
Joseph F. V. Allingham, Adi Zitrin, Vasily Kokorev +42
We present a parametric strong-lensing model for the galaxy cluster MACS J1931.8-2635 (), accompanying the detection of the spectroscopically confirmed SN Eos at $z = 5…
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…
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…
EMPRESS. XV. A New Determination of the Primordial Helium Abundance Suggesting a Moderately Low Value
Hiroto Yanagisawa, Masami Ouchi, Akinori Matsumoto +18
We present a new constraint on the primordial helium abundance, , based on Subaru observations. A major source of uncertainty in previous determination…