120 citations · 946 across the 56 of their papers we have counts for
56 papers
A Broken Clock Is Right Twice a Day: [Ce/Mg] Is Not a Universal Chemical Clock
Liam O. Dubay, Jennifer A. Johnson, James W. Johnson +14
The ratio of -process to -element enrichment () has been proposed as a ``chemical clock,'' or a means to estimate stellar ages. However, the age-- relation vari…
The Open Cluster Chemical Abundances and Mapping Survey XI. First Gradients from SDSS/MWM BOSS Determined Clusters
Jonah M. Otto, Peter M. Frinchaboy, John Donor +13
The Milky Way Mapper program in the fifth generation of the Sloan Digital Sky Survey (SDSS-V/MWM) has observed millions of stars, thousands of them in open clusters. The Open Clust…
Long-term high-resolution spectroscopic monitoring of the evolved metal-poor binary PS Gem
V. G. Klochkova, V. E. Panchuk, J. K. Zhao +3
We present results of long-term high-resolution spectroscopic monitoring of the extremely low-metallicity star PS Gem (=HD 52961), associated with IRAS 07008+1050. The spectra were…
The Twentieth Data Release of the Sloan Digital Sky Survey: First All-Sky BOSS Spectra, eROSITA-SDSS-V Mapper Coordinated Observations, and a Preview of the Local Volume Mapper
SDSS Collaboration, Mojgan Aghakhanloo, David Aguilar +273
This paper presents the twentieth data release (DR20) from the Sloan Digital Sky Survey, the third data release of its fifth generation (SDSS-V). SDSS-V is a panoptic spectroscopy…
Long Tidal Tails of NGC 5024 Hidden in LMS-1 and NGC 5053 Tidal Streams
Xianhao Ye, Yong Yang, Jingkun Zhao +3
We report the discovery of long tidal tails associated with the globular cluster (GC) NGC 5024. A modified matched filter applied to Gaia DR3 data reveals a broad stellar stream sp…
Probabilistic Stellar Age Estimation for Gaia XP Stars with NGBoost
Xiaokun Hou, Wenbo Wu, Gang Zhao +2
Stellar age is a fundamental quantity for Galactic archaeology, but reliable age estimation for large stellar samples remains challenging. In this work, we develop an uncertainty a…
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…
The Stellar Abundances and Galactic Evolution Survey (SAGES). V. The First Data Release of the DDO51 Band
Qiqian Zhang, Zhou Fan, Gang Zhao +20
We present the first public data release of DDO51 band from the Stellar Abundances and Galactic Evolution Survey (SAGES), based on Nanshan One-meter Wide-field Telescope (NOWT) obs…
Mapping the Milky Way with Gaia Bp/Rp spectra-IV: the broken and asymmetric density profile of the stellar disk traced by a large sample of red clumps
Wenbo Wu, Yuqin Chen, Jianhui Lian +10
This study explores the density profile of the stellar disk, radially and azimuthally, based on approximately 8.4 million red clump stars selected from Gaia Bp/Rp spectra. After co…
Revisiting Ca II Activity Indices in FGK Stars: Systematic Biases in Infrared Triplet Measurements
Xiaozhen Yang, Xiaoting Fu, Mingjie Jian +10
Synthetic-template subtraction is widely used to measure chromospheric activity in large spectroscopic surveys. However, many solar-like FGK stars show systematically negative Ca I…
Galactic Archaeology with the Subaru `Ōnohi`ula Prime Focus Spectrograph Strategic Program
Masashi Chiba, Rosemary F. G. Wyse, Evan N. Kirby +48
The recently commissioned Subaru `Ōnohi`ula Prime Focus Spectrograph (PFS) will obtain spectra from nearly 2,400 fibers that cover 1.24 square degrees. The 360 night Subaru Strateg…
A Highly Magnetic Ultra Massive White Dwarf with a 23-minute Rotation Period
Jincheng Guo, Xiaofeng Wang, Qichun Liu +17
We present a physical characterization of TMTS J00063798+3104160 (J0006), a rapidly rotating,ultra-massive white dwarf (WD) identified in high-cadence light curves from the Tsinghu…
Looking for Signs of Unresolved Binarity in the Continuum of LAMOST Stellar Spectra
Mikhail Prokhorov, Kefeng Tan, Nikolay Samus +10
We describe an attempt to derive the binarity rate of samples of 166 A-, F-, G-, and K-type stars from LAMOST DR5 and 1000 randomly selected presumably single stars from Gaia DR3 c…
Moving Groups in the Solar Neighborhood with Gaia, APOGEE, GALAH, and LAMOST: Dynamical Effects Gather Gas and the Ensuing Star Formation Plays an Important Role in Shaping the Stellar Velocity Distributions
Xilong Liang, Suk-Jin Yoon, Jingkun Zhao
With Gaia, APOGEE, GALAH, and LAMOST data, we investigate the positional, kinematic, chemical, and age properties of nine moving groups in the solar neighborhood. We find that each…
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…
Variable white dwarfs in TMTS: Asteroseismological analysis of a ZZ Ceti star, TMTS J17184064+2524314
Jincheng Guo, Yanhui Chen, Yonghui Yang +24
The Tsinghua University-Ma Huateng Telescope for Survey (TMTS) has been constantly monitoring the northern sky since 2020 in search of rapidly variable stars. To find variable whit…
Candidate Members of the VMP/EMP Disk System of the Galaxy from the SkyMapper and SAGES Surveys
Jihye Hong, Timothy C. Beers, Young Sun Lee +15
Photometric stellar surveys now cover a large fraction of the sky, probe to fainter magnitudes than large-scale spectroscopic surveys, and are relatively free from the target-selec…
On the Migration Origin of the Hercules Moving Group with GAIA, LAMOST, APOGEE, and GALAH Surveys
Xilong Liang, Suk-Jin Yoon, Jingkun Zhao +3
Using Gaia DR3 data and the wavelet transformation technique, we study the substructures of the Hercules moving group (HMG): Hercules 1 (H1) and Hercules 2 (H2). Spectroscopic surv…
Beyond spectroscopy. II. Stellar parameters for over twenty million stars in the northern sky from SAGES DR1 and Gaia DR3
Yang Huang, Timothy C. Beers, Hai-Bo Yuan +18
We present precise photometric estimates of stellar parameters, including effective temperature, metallicity, luminosity classification, distance, and stellar age, for nearly 26 mi…
The Stellar Abundances and Galactic Evolution Survey (SAGES) -- -- I. General Description and the First Data Release (DR1)
Zhou Fan, Gang Zhao, Wei Wang +35
The Stellar Abundances and Galactic Evolution Survey (SAGES) of the northern sky is a specifically-designed multi-band photometric survey aiming to provide reliable stellar paramet…
Mass distribution for single-lined hot subdwarf stars in LAMOST
Zhenxin Lei, Ruijie He, Peter Nemeth +4
Masses for 664 single-lined hot subdwarf stars identified in LAMOST were calculated by comparing synthetic fluxes from spectral energy distribution (SED) with observed fluxes from…
The Spectacular Tidal Tails of Globular Cluster M3 (NGC 5272)
Yong Yang, Jing-Kun Zhao, Xin-Zhe Tang +2
We provide a detailed analysis on tidal tails of the globular cluster M3 (NGC 5272). We first discover clear extra-tidal structures with slight S-shape near the cluster. This inspi…
Properties and Asteroseismological analysis of a new ZZ ceti discovered by TMTS
Jincheng Guo, Yanhui Chen, Xiaofeng Wang +24
Tsinghua university-Ma Huateng Telescope for Survey (TMTS) aims to discover rapidly evolving transients by monitoring the northern sky. The TMTS catalog is cross-matched with the w…