activity
20242026
most citedCluster candidates with massive quiescent galaxies at

7 citations · 14 across the 14 of their papers we have counts for

collaborators

15 papers

astro-ph.GA2026

SN Helios: A Multiply Imaged Type II Supernova Opening Time-Delay Cosmography beyond redshift of 3

Seiji Fujimoto, Conor Larison, Justin D. R. Pierel +64

We report the discovery and spectroscopic confirmation of SN Helios, a strongly lensed, multiply imaged Type II supernova (SN) at behind the galaxy cluster RXC J0018.5+162…

astro-ph.GA2026

Free-Free Radio Emission from Little Red Dots as a Probe of Ionized Gas

Takumi S. Tanaka, Kohei Inayoshi, Zu Yan +3

Recent studies have hypothesized that little red dots (LRDs) are rapidly accreting black holes surrounded by dense gaseous environments. Both neutral and ionized gas play a key rol…

astro-ph.GA2026

ATLAS. IV. A JWST+MUSE Demographic Study of Ly Profiles in Little Red Dots

Yuta Kageura, Masami Ouchi, Hiroto Yanagisawa +6

We present an initial demographic study of Ly profiles in little red dots (LRDs) at --9 using --4000 spectroscopy. Our sample consists of 8 LRDs observed in the…

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 Archive…

astro-ph.GA2026

ATLAS. I. 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

SDSS+JWST Census of Stellar and Nebular Dust Attenuation at -7: Mass Dependence and Redshift Evolution

Jie Song, Masami Ouchi, Tomokazu Kiyota +3

We present the demography of dust attenuation, including its mass dependence and redshift evolution, using spectroscopic samples of 34,182 SDSS galaxies at and 863 JWST/…

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…

astro-ph.GA2026★ 1 cited

Back to Normal Again: Possible Destinies of JWST overmassive SMBHs and "Little Red Dots" in the View of Shin-Uchuu Simulation

Haojie Hu, Hiroto Yanagisawa, Moka Nishigaki +3

The James Webb Space Telescope (JWST) has enabled the discovery of hundreds of supermassive black holes (SMBHs) at redshifts . A non-negligible fraction of these SMBH…

astro-ph.GA2026

JWST Spectroscopic Census of ALMA Faint Submillimeter Galaxies in the Hubble Ultra Deep Field

Tomokazu Kiyota, Masami Ouchi, Daisuke Iono +6

We present a JWST/NIRSpec rest-frame optical spectroscopic census of ALMA 1-mm continuum sources in the Hubble Ultra Deep Field (UDF) identified by the deep ALMA UDF and ASPECS pro…

astro-ph.GA2025★ 1 cited

Little red dot variability over a century reveals black hole envelope via a giant Einstein cross

Zijian Zhang, Mingyu Li, Masamune Oguri +79

"Little red dots" (LRDs) represent a new population of astronomical objects uncovered by JWST whose nature remains debated. Although many LRDs are suspected as active galactic nucl…

astro-ph.GA2025★ 1 cited

VENUS: A Strongly Lensed Clumpy Galaxy at behind the Galaxy Cluster MACS J0257.1-2325

Minami Nakane, Vasily Kokorev, Seiji Fujimoto +75

We present the discovery of a strongly lensed galaxy at , dubbed the ``Misty Moons'', identified in the JWST Treasury Survey, Vast Exploration for Nascent, Unexplored S…

astro-ph.GA2025★ 1 cited

Comprehensive JWST+ALMA Study on the Extended Ly Emitters, Himiko and CR7 at : Blue Major Merger Systems in Stark Contrast to Submillimeter Galaxies

Tomokazu Kiyota, Masami Ouchi, Yi Xu +14

We present various properties of two bright extended Ly objects, Himiko and CR7, at thoroughly investigated with JWST/NIRCam photometry, NIRSpec-IFU spectroscopy, and AL…

astro-ph.GA2024★ 3 cited

Hidden in Pixels. I. Discovery of dual "little red dots" indicates excess clustering on kilo-parsec scales

Takumi S. Tanaka, John D. Silverman, Kazuhiro Shimasaku +56

``Little Red Dots'' (LRDs) are an abundant high-redshift population newly discovered by the James Webb Space Telescope (JWST) and considered to be an early growth phase of supermas…

astro-ph.GA2024★ 7 cited

Cluster candidates with massive quiescent galaxies at

Tomokazu Kiyota, Makoto Ando, Masayuki Tanaka +7

Galaxy clusters are crucial to understanding role of the environment in galaxy evolution. However, due to their rarity, only a limited number of clusters have been identified at $z…