156 citations · 420 across the 19 of their papers we have counts for
22 papers
Abundance analysis of three new extremely metal-poor stars, including one CEMP-s star
P. François, T. Suda, S. Wanajo +5
We report a detailed abundance analysis of three extremely metal-poor (EMP) stars thanks to spectra obtained with the high-dispersion spectrograph (HDS) at the Subaru telescope. Th…
Near-infrared spectra of chemically peculiar stars and applications to kilonova spectra
Nanae Domoto, Masaomi Tanaka, Wako Aoki +11
Kilonova spectra provide information on rapid neutron-capture nucleosynthesis in neutron star mergers. However, it remains challenging to identify individual elements in kilonova s…
Bright Metal-Poor Star Survey - I. Tomo-e Gozen narrow-band photometric survey and medium-resolution spectroscopic follow-up
Hiroko Okada, Takumi Iwasaki, Nozomu Tominaga +21
We present the Tomo-e Gozen Bright Metal-Poor Star Survey (TeMPS), a wide-area narrow-band photometric survey for bright metal-poor stars in the northern sky. The survey uses the T…
Revealing α-Element's Past with Subaru/IRD: Oxygen Abundance of 35 Very Metal-Poor Stars from Near-IR OH lines
Bakuh Danang Setyo Budi, Wako Aoki, Nicholas Storm +10
Oxygen abundances in very and extremely metal-poor (V/EMP) stars provide critical constraints on early massive stars' nucleosynthesis. An Oxygen abundance analysis is presented for…
A Systematic NLTE Study of Very Metal-Poor Stars with Metallicity Down to dex. II. Lithium Abundance and New Insight to the Lithium Plateau
Hong-Liang Yan, Jinxiao Qin, Shuai Liu +12
Metal-poor stars are crucially important for understanding the early Galaxy, first stars, and the Universe. In this series of papers, we present a homogeneous non-local thermodynam…
SMSS J022423.27573705.1: An Extremely Metal-Poor Star with the Most Pronounced Weak -Process Signature
Hiroko Okada, Wako Aoki, Nozomu Tominaga +1
We present the measurement of 26 elemental abundances of SMSS J022423.27573705.1 (SMSS 02245737), an extremely metal-poor (EMP) star with a weak -process signature. We rep…
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…
Chemical abundances of seven stars in the GD-1 stream
Jing-Kun Zhao, Guang-Wei Li, Wako Aoki +13
We present the first detailed chemical abundances for seven GD-1 stream stars from Subaru/HDS spectroscopy. Atmospheric parameters were derived via color calibrations (…
Detailed Chemical Abundance Analysis of Metal-Poor Turn-Off Stars: One with [Fe/H] < -4 and Three with [Fe/H] < -3
Takuma Suda, Patrick Francois, Shinya Wanajo +3
We present the analysis of four new extremely metal poor turn-off stars thanks to high-resolution spectra obtained with the Subaru/HDS spectrograph. We determined the abundances an…
Th/Eu abundance ratio of red giants in the Kepler Field
Ainun Azhari, Tadafumi Matsuno, Wako Aoki +2
The r-process production in the early universe has been well constrained by the extensive studies of metal-poor stars. However, the r-process enrichment in the metal-rich regime is…
An Actinide-boost Star Discovered in the Gaia-Sausage-Enceladus
Yangming Lin, Haining Li, Ruizheng Jiang +6
We report the discovery of an actinide-boost, very metal-poor (), -process-enhanced () star, LAMOST J0804+5…
Elemental abundances of 44 very metal-poor stars determined from Subaru/IRD near-infrared spectra
Wako Aoki, Timothy C. Beers, Satoshi Honda +12
Abundances of five elements, Na, Mg, Al, Si, and Sr, are investigated for 44 very metal-poor stars (-4.0 < [Fe/H] < -1.5) in the Galactic halo system based on an Local Thermodinami…
Revisiting Near-Infrared Features of Kilonovae: The Importance of Gadolinium
Salma Rahmouni, Masaomi Tanaka, Nanae Domoto +7
The observation of the kilonova AT2017gfo and investigations of its light curves and spectra confirmed that neutron star mergers are sites of r-process nucleosynthesis. However, th…
Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy
M. Kuzuhara, A. Fukui, J. H. Livingston +103
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observ…
Four-hundred Very Metal-poor Stars Studied with LAMOST and Subaru. III. Dynamically Tagged Groups and Chemodynamical Properties
Ruizhi Zhang, Tadafumi Matsuno, Haining Li +9
Very metal-poor (VMP) stars record the signatures of early accreted galaxies, making them essential tools for unraveling the early stages of Galaxy formation. Understanding the ori…
Detection of the actinide Th in an r-process-enhanced star with accretion origin
Xing Qianfan, Zhao Gang, Aoki Wako +4
The thorium and six second-peak r-process element (56<Z<72) abundances are determined for the alpha-poor star LAMOST J1124+4535 based on a high-resolution spectrum obtained with th…
"Dark" GRB 080325 in a Dusty Massive Galaxy at z ~ 2
T. Hashimoto, K. Ohta, K. Aoki +30
We present optical and near infrared observations of GRB 080325 classified as a "Dark GRB". Near-infrared observations with Subaru/MOIRCS provided a clear detection of afterglow in…
HD 209621: Abundances of neutron-capture elements
Aruna Goswami, Wako Aoki
High resolution spectra obtained from the Subaru Telescope High Dispersion Spectrograph have been used to update the stellar atmospheric parameters and metallicity of the star HD 2…
Chemical Abundances of the Outer Halo Stars in the Milky Way
M. Ishigaki, M. Chiba, W. Aoki
We present chemical abundances of 57 metal-poor stars that are likely constituents of the outer stellar halo in the Milky Way. Almost all of the sample stars have an orbit reaching…
Subaru/HDS Abundances in Three Giant Stars in the Ursa Minor Dwarf Spheroidal Galaxy
K. Sadakane, N. Arimoto, C. Ikuta +3
With the HDS (High Dispersion Spectrograph) on the Subaru telescope, we obtained high resolution optical region spectra of three red giant stars (cos 4, cos 82, and cos 347) in the…
Current Performance and On-Going Improvements of the 8.2 m Subaru Telescope
Masanori Iye, Hiroshi Karoji, Hiroyasu Ando +2
An overview of the current status of the 8.2 m Subaru Telescope constructed and operated at Mauna Kea, Hawaii, by the National Astronomical Observatory of Japan is presented. The b…
Lithium 6104A in Population II stars
A. Ford, R. D. Jeffries, B. Smalley +5
We have obtained echelle spectroscopy of 14 Population II objects selected from those previously observed by Bonifacio & Molaro (1997). For one object, HD 140283, we obtained exqui…