211 citations · 1.4k across the 46 of their papers we have counts for
19 papers · 1 filter
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…
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 (…
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)…
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…
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…
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…
High-precision chemical abundances of Galactic building blocks. II. Revisiting the chemical distinctness of the Helmi streams
Tadafumi Matsuno, Emma Dodd, Helmer H. Koppelman +6
Context: The Helmi streams are a kinematic substructure whose progenitor is likely a dwarf galaxy. Although 20 years have passed since their discovery, it is still unclear whether…
Substructure in the stellar halo near the Sun. II. Characterisation of independent structures
Tomás Ruiz-Lara, Tadafumi Matsuno, S. Sofie Lövdal +3
In Lövdal et al, we presented a data-driven method for clustering in Integrals of Motion space and applied it to a large sample of nearby halo stars with 6D phase-space information…
Substructure in the stellar halo near the Sun. I. Data-driven clustering in Integrals of Motion space
S. Sofie Lövdal, Tomás Ruiz-Lara, Helmer H. Koppelman +3
Aims: Develop a data-driven and statistically based method for finding such clumps in Integrals of Motion space for nearby halo stars and evaluating their significance robustly. Me…
High-precision chemical abundances of Galactic building blocks. The distinct chemical abundance sequence of Sequoia
Tadafumi Matsuno, Helmer H. Koppelman, Amina Helmi +5
Context: Sequoia is a retrograde kinematic substructure in the nearby Galactic halo, whose properties are a matter of debate. For example, previous studies do not necessarily agree…
-process enhancements of Gaia-Enceladus in GALAH DR3
Tadafumi Matsuno, Yutaka Hirai, Yuta Tarumi +3
The dominant site of production of -process elements remains unclear despite recent observations of a neutron star merger. Observational constraints on the properties of the sit…
Dynamical Relics of the Ancient Galactic Halo
Zhen Yuan, G. C. Myeong, Timothy C. Beers +11
We search for dynamical substructures in the LAMOST DR3 very metal-poor (VMP) star catalog. After cross-matching with Gaia DR2, there are 3300 VMP stars with available high-quality…
Origin of the excess of high-energy retrograde stars in the Galactic halo
Tadafumi Matsuno, Wako Aoki, Takuma Suda
We report on the very low -element abundances of a group of metal-poor stars with high orbital energy and with large retrograde motion in the Milky Way halo, whose excess has be…
Tracing the origin of moving groups I. The γ Leo moving group with high resolution spectra from the Subaru Telescope
Xilong Liang, Jingkun Zhao, Gang Zhao +7
We present chemical abundances of 15 stars in the γ Leo moving group based on high-resolution spectra with the Subaru High Dispersion Spectrograph. The sample was picked up by appl…
Structure of the Milky Way stellar halo out to its outer boundary with blue horizontal-branch stars
Tetsuya Fukushima, Masashi Chiba, Daisuke Homma +6
We present the structure of the Milky Way stellar halo beyond Galactocentric distances of kpc traced by blue horizontal-branch (BHB) stars, which are extracted from the su…