activity
20002026
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 · 755 across the 27 of their papers we have counts for

collaborators

28 papers

astro-ph.SR2026★ 1 cited

JWST-DECO: Temporal Variations in the Mid-IR Silicate Features of Two T Tauri Discs Based on Spitzer and JWST observations

N. Sameshima, T. Miyata, T. Kamizuka +9

Mid-infrared spectra of planet-forming discs commonly show prominent silicate emission, whose spectral shape is sensitive to the disc temperature distribution as well as its minera…

astro-ph.HE2023★ 8 cited

SN 2020uem: A Possible Thermonuclear Explosion within A Dense Circumstellar Medium (I) The Nature of Type IIn/Ia-CSM SNe from Photometry and Spectroscopy

Kohki Uno, Keiichi Maeda, Takashi Nagao +18

We have performed intensive follow-up observations of a Type IIn/Ia-CSM SN (SN IIn/Ia-CSM), 2020uem, with photometry, spectroscopy, and polarimetry. In this paper, we report on the…

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

astro-ph.SR2020★ 4 cited

Long-Term Near-Infrared Brightening of Non-Variable OH/IR Stars

Takafumi Kamizuka, Yoshikazu Nakada, Kenshi Yanagisawa +8

Non-variable OH/IR stars are thought to have just left the asymptotic giant branch (AGB) phase. In this conventional picture, they must still show strong circumstellar extinction c…

astro-ph.EP2020★ 6 cited

Relationship between Radar Cross Section and Optical Magnitude based on Radar and Optical Simultaneous Observations of Faint Meteors

Ryou Ohsawa, Akira Hirota, Kohei Morita +40

Radar and optical simultaneous observations of meteors are important to understand the size distribution of the interplanetary dust. However, faint meteors detected by high power l…

astro-ph.IM2019★ 12 cited

An optical search for transients lasting a few seconds

Michael W. Richmond, Masaomi Tanaka, Tomoki Morokuma +37

Using a prototype of the Tomo-e Gozen wide-field CMOS mosaic camera, we acquire wide-field optical images at a cadence of 2 Hz and search them for transient sources of duration 1.5…