211 citations · 1.4k across the 46 of their papers we have counts for
48 papers
Snapshots of r-process production in the Milky Way disk
Sarah G. Kane, Stephanie Monty, Madeleine McKenzie +9
Stars enhanced in heavy neutron capture elements like europium (Eu) provide a window into the rarest and most exotic nucleosynthetic events. Most Eu-enhanced stars discovered thus…
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…
HRMOS: A High-Resolution Multi-Object Spectrograph for the VLT
Laura Magrini, Thomas Bensby, Sofia Randich +174
This White Paper presents the scientific rationale and instrument concept for HRMOS (High-Resolution Multi-Object Spectrograph), a next-generation instrument proposed for the ESO V…
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…
A nearly pristine star from the Large Magellanic Cloud
Alexander P. Ji, Vedant Chandra, Selenna Mejias-Torres +28
The first stars formed out of pristine gas, causing them to be so massive that none are expected to have survived until today. If their direct descendants were sufficiently low-mas…
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 (…
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…
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…
Unevolved Li-rich stars at low metallicity: a possible formation pathway through novae
Tadafumi Matsuno, Alex Kemp, Ataru Tanikawa +7
A small fraction of low-mass stars have been found to have anomalously high Li abundances. Although it has been suggested that mixing during the red giant branch phase can lead to…
Final results for mapping the Milky Way's stellar halo with blue horizontal-branch stars selected from the Subaru Hyper Supreme-Cam Survey
Tetsuya Fukushima, Masashi Chiba, Mikito Tanaka +7
We select blue-horizontal branch stars (BHBs) from the internal data release of the Hyper Suprime-Cam Subaru Strategic Program to reveal the global structure of the Milky Way (MW)…
A distinct halo population revealed from 3D non-LTE magnesium abundances
T. Matsuno, A. M. Amarsi, M. Carlos +1
Magnesium is one of the important elements in stellar physics as an electron donor and in Galactic Archaeology as a discriminator of different stellar populations. However, previou…
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…
The Wide-field Spectroscopic Telescope (WST) Science White Paper
Vincenzo Mainieri, Richard I. Anderson, Jarle Brinchmann +214
The Wide-field Spectroscopic Telescope (WST) is proposed as a new facility dedicated to the efficient delivery of spectroscopic surveys. This white paper summarises the initial con…
Unique chemical composition of the very metal-poor star LAMOST J1645+4357
Wako Aoki, Haining Li, Nozomu Tominaga +3
We report on the chemical composition of the very metal-poor ([Fe/H]=-2.9) star LAMOST J1645+4357 that is identified to be a red giant having peculiar abundance ratios by Li et al.…
Gaia's brightest very metal-poor (VMP) stars. Metallicity catalogue of a thousand VMP stars from Gaia's radial velocity spectrometer spectra
Akshara Viswanathan, Else Starkenburg, Tadafumi Matsuno +10
Context. Gaia DR3 has offered the scientific community a remarkable dataset of approximately one million spectra acquired with the Radial Velocity Spectrometer (RVS) in the Calcium…
GHOST Commissioning Science Results II: a very metal-poor star witnessing the early Galactic assembly
Federico Sestito, Christian R. Hayes, Kim A. Venn +25
This study focuses on Pristine (hereafter P180956, ), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up…
Trading oxygen for iron I: the [O/Fe] -- specific star formation rate relation of galaxies
Martyna Chruślińska, Ruediger Pakmor, Jorryt Matthee +1
Our current knowledge of star-forming metallicity relies primarily on gas-phase oxygen abundance measurements. This may not allow one to accurately describe differences in stellar…
ED-2: a cold but not so narrow stellar stream crossing the Solar neighbourhood
E. Balbinot, A. Helmi, T. Callingham +3
ED-2 is a stellar stream identified as a compact group in integrals of motion space in a local sample of halo stars from the third Gaia data release. Here we investigate its nature…
Improving metallicity estimates for very metal-poor stars in the Gaia DR3 GSP-Spec catalog
Tadafumi Matsuno, Else Starkenburg, Eduardo Balbinot +1
The Gaia DR3 GSP-Spec parameters, including metallicity, for VMP stars suffer from parameter degeneracy due to a lack of information in their spectra. Furthermore, the recommended…
The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation
Shoko Jin, Scott C. Trager, Gavin B. Dalton +212
WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for the William Herschel Telescope, will see first light in late 2022. WEAVE comprises a new 2-degree…
Gaia DR2 and EDR3 data and evolutionary status of post-AGB stars with high radial velocities
Wako Aoki, Tadafumi Matsuno, Mudumba Parthasarathy
Using the Gaia DR2 and EDR3 data and list of post-AGB candidates, we investigate the parallax, proper motion and binarity for twenty post-AGB stars and candidates having high radia…
The Gaia DR3 view of dynamical substructure in the stellar halo near the Sun
Emma Dodd, Thomas M. Callingham, Amina Helmi +4
The debris from past merger events is expected and, to some extent, known to populate the stellar halo near the Sun. We aim to identify and characterise such merger debris using Ga…