Publications (54)
Determining Stellar Elemental Abundances from DESI Spectra with the Data-Driven Payne
Meng Zhang, Maosheng Xiang, Yuan-Sen Ting +8
Stellar abundances for a large number of stars are key information for the study of Galactic formation history. Large spectroscopic surveys such as DESI and LAMOST take median-to-l…
The Kinematic and Chemical Properties of the Close-in Planet Host Star 8 UMi
Huiling Chen, Yang Huang, Wei Zhu +11
A recent study by Hon et al. reported that a close-in planet around the red clump star, 8 UMi, should have been engulfed during the expansion phase of its parent star's evolution.…
Metal-poor Stars Observed with the Automated Planet Finder Telescope. II. Chemodynamical Analysis of Six Low-Metallicity Stars in the Halo System of the Milky Way
Mohammad K. Mardini, Vinicius M. Placco, Ali Taani +2
In this work, we study the chemical compositions and kinematic properties of six metal-poor stars with [Fe/H] in the Galactic halo. From high-resolution (R ~110,000)…
Discovery of a strongly r-process enhanced extremely metal-poor star LAMOST J110901.22+075441.8
Haining Li, Wako Aoki, Satoshi Honda +3
We report the discovery of an extremely metal-poor (EMP) giant, LAMOST J110901.22+075441.8, which exhibits large excess of r-process elements with [Eu/Fe] ~ +1.16. The star is one…
High-resolution spectroscopic studies of ultra metal-poor stars found in LAMOST survey
Haining Li, Wako Aoki, Gang Zhao +3
We report on the observations of two ultra metal-poor (UMP) stars with [Fe/H]~-4.0 including one new discovery. The two stars are studied in the on-going and quite efficient projec…
Star Formation Timescales of the Halo Populations from Asteroseismology and Chemical Abundances
Tadafumi Matsuno, Wako Aoki, Luca Casagrande +9
We combine asteroseismology, optical high-resolution spectroscopy, and kinematic analysis for 26 halo red giant branch stars in the \textit{Kepler} field in the range of $-2.5<[\ma…
Metal-poor stars observed with the automated planet finder telescope. I. Discovery of five carbon-enhanced metal-poor stars from LAMOST
Mohammad K. Mardini, Haining Li, Vinicius M. Placco +6
We report on the discovery of five carbon-enhanced metal-poor (CEMP) stars in the metallicity range of [Fe/H] . These stars were selected from the LAMOST DR3 low-res…
Stellar Loci VI: An Updated Catalog of the Best and Brightest Metal-poor Stars
Shuai Xu, Haibo Yuan, Ruoyi Zhang +3
We employ Gaia, 2MASS, and ALLWISE photometry, as well as astrometric data from Gaia, to search for relatively bright very metal-poor ([Fe/H] ; VMP) giant star candidates u…
Enormous Li-enhancement preceding red giant phases in low-mass stars in the Milky Way halo
Haining Li, Wako Aoki, Tadafumi Matsuno +4
Li abundances in the bulk of low-mass metal-poor stars are well reproduced by stellar evolution models adopting a constant initial abundance. However, a small number of stars have…
HR-GO II: chemical abundances of low- retrograde dynamically-tagged-groups: Revealing Thamnos as a very metal-poor substructure
Renjing Xie, Zhen Yuan, Haining Li +12
Milky Way halo substructures identified in dynamical space are known to suffer from contamination from the Milky Way in-situ stars, which makes their accreted origins uncertain. We…
Four-hundred Very Metal-Poor Stars Studied with LAMOST and Subaru. II. Elemental abundances
Haining Li, Wako Aoki, Tadafumi Matsuno +9
We present homogeneous abundance analysis of over 20 elements for 385 very metal-poor (VMP) stars based on the LAMOST survey and follow-up observations with the Subaru Telescope. I…
Where are the Population III star relics in the simulated Milky Way analogues?
Hang Yang, Liang Gao, Qi Guo +3
Using 6 Milky Way analogues with two different numerical resolutions from the Auriga simulation, we investigate the total mass, spatial distribution and kinematics of the Populatio…
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…
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…
Trustworthy Long-Tailed Classification
Bolian Li, Zongbo Han, Haining Li +2
Classification on long-tailed distributed data is a challenging problem, which suffers from serious class-imbalance and accordingly unpromising performance especially on tail class…
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.…
Overview of the LAMOST survey in the first decade
Hongliang Yan, Haining Li, Song Wang +24
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), also known as the Guoshoujing Telescope, is a major national scientific facility for astronomical research l…
A Modified Initial Mass Function of the First Stars with Explodability Theory under Different Enrichment Scenarios
Ruizheng Jiang, Gang Zhao, Haining Li +1
The most metal-poor stars record the earliest metal enrichment triggered by Population III stars. By comparing observed abundance patterns with theoretical yields of metal-free sta…
Observational constraints on the survival of pristine stars
Mattis Magg, Ralf S. Klessen, Simon C. O. Glover +1
There is a longstanding discussion about whether low mass stars can form from pristine gas in the early Universe. A particular point of interest is whether we can find surviving pr…
LAMOST J2217+2104: a new member of carbon-enhanced extremely metal-poor stars with excesses of Mg and Si
Wako Aoki, Tadafumi Matsuno, Satoshi Honda +4
We report on the elemental abundances of the carbon-enhanced metal-poor (CEMP) star J2217+2104 discovered by our metal-poor star survey with LAMOST and Subaru. This object is a red…
Lithium in CEMP-no stars: A new constraint on the lithium depletion mechanism in the early universe
Tadafumi Matsuno, Wako Aoki, Takuma Suda +1
Most of relatively warm, unevolved metal-poor stars ( and ) exhibit almost constant lithium abundances, irrespective…
Automatic Determination of Stellar Atmospheric Parameters and Construction of Stellar Spectral Templates of the Guoshoujing Telescope (LAMOST)
Yue Wu, A-Li Luo, Haining Li +10
A number of spectroscopic surveys have been carried out or are planned to study the origin of the Milky Way. Their exploitation requires reliable automated methods and softwares to…
Introduction to the Chinese Space Station Survey Telescope (CSST)
CSST Collaboration, Yan Gong, Haitao Miao +119
The Chinese Space Station Survey Telescope (CSST) is an upcoming Stage-IV sky survey telescope, distinguished by its large field of view (FoV), high image quality, and multi-band o…
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…
Fuzzy Cluster Analysis: Application to Determining Metallicities for Very Metal-poor Stars
Haining Li
This work presents a first attempt to apply fuzzy cluster analysis (FCA) to analyzing stellar spectra. FCA is adopted to categorize line indices measured from LAMOST low-resolution…
High-α-Metal-Rich stars in the LAMOST-MRS survey and its connection with the galactic bulge
Haopeng Zhang, Yuqin Chen, Gang Zhao +6
We report the detection of a large sample of high--metal-rich stars on the low giant branch with dex in the LAMOST-MRS survey. This special group corresponds to…
Main-sequence Turnoff Stars as Probes of the Ancient Galactic Relic: Chemo-dynamical Analysis of a Pilot Sample
Renjing Xie, Haining Li, Ruizhi Zhang +5
The main-sequence turnoff (MSTO) stars well preserve the chemical properties where they were born, making them ideal tracers for studying the stellar population. We perform a detai…
Technical Report: A Hierarchical Dynamically Weighting Deep Reinforcement Learning Method for Multi-UAV Multi-Task Coordination
Xindi Wang, Haining Li, Tao Ding +1
This paper investigates the multi-UAV multi-task coordination problem in infrastructure-less emergency scenarios, where UAVs collaboratively are required to jointly perform aerial…
Milky Way Dynamics Favor Dark Matter over Modified Gravity Models
Zheng-long Wang, Yue-Lin Sming Tsai, Lan Zhang +5
Modified gravity theories such as Modified Newtonian Dynamics (MOND) and Scalar-Tensor-Vector Gravity (STVG) have been proposed as alternatives to dark matter, but decisive tests h…
Proton-rich production of lanthanides: the process
Xilu Wang, Amol V. Patwardhan, Yangming Lin +7
The astrophysical origin of the lanthanides is an open question in nuclear astrophysics. Besides the widely studied , , and processes in moderately-to-strongly neutron-ri…
A Catalog of 12,766 Carbon-enhanced Metal-poor Stars from LAMOST Data Release 8
Ziyu Fang, Xiangru Li, Haining Li
Metal-poor stars are a rare and ancient type of stars; Carbon-Enhanced Metal-Poor (CEMP) stars are a subset of these celestial bodies that show an enrichment of carbon relative to…
Spectacular nucleosynthesis from early massive stars
Alexander P. Ji, Sanjana Curtis, Nicholas Storm +39
Stars formed with initial mass over 50 Msun are very rare today, but they are thought to be more common in the early universe. The fates of those early, metal-poor, massive stars a…
The Stellar Abundances and Galactic Evolution Survey (SAGES). IV. Surface Gravity Estimation and Giant-Dwarf Separation with the DDO51 Filter
Qiqian Zhang, Zhou Fan, Gang Zhao +16
Reliable estimation of stellar surface gravity (log ) for a large sample is crucial for evaluating stellar evolution models and understanding galactic structure; However, it is…
The Stellar Abundances and Galactic Evolution Survey (SAGES). II. Machine Learning-Based Stellar parameters for 21 million stars from the First Data Release
Hongrui Gu, Zhou Fan, Gang Zhao +14
Stellar parameters for large samples of stars play a crucial role in constraining the nature of stars and stellar populations in the Galaxy. An increasing number of medium-band pho…
Progress in Nuclear Astrophysics of East and Southeast Asia
Azni Abdul Aziz, Nor Sofiah Ahmad, S. Ahn +25
Nuclear astrophysics is an interdisciplinary research field of nuclear physics and astrophysics, seeking for the answer to a question, how to understand the evolution of the Univer…
Morphological Dependence of MIR Properties of SDSS Galaxies in the Spitzer SWIRE Survey
Haining Li, Hong Wu, Chen Cao +1
We explore the correlation between morphological types and mid-infrared (MIR) properties of an optically flux-limited sample of 154 galaxies from the Forth Data Release (DR4) of Sl…
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…
Planets Around Solar Twins/Analogs (PASTA) I.: High precision stellar chemical abundance for 17 planet-hosting stars and the condensation temperature trend
Qinghui Sun, Sharon Xuesong Wang, Tianjun Gan +30
The Sun is depleted in refractory elements compared to nearby solar twins, which may be linked to the formation of giant or terrestrial planets. Here we present high-resolution, hi…
ET White Paper: To Find the First Earth 2.0
Jian Ge, Hui Zhang, Weicheng Zang +163
We propose to develop a wide-field and ultra-high-precision photometric survey mission, temporarily named "Earth 2.0 (ET)". This mission is designed to measure, for the first time,…
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…
Milky Way Mass Through Escape Velocity Curve from LAMOST K Giants
Yin Wu, Haining Li, Yang Huang +2
Escape velocity has long been used to constrain the mass of the Dark Matter (DM) halo in the Milky Way (MW). Here we present a study of the escape velocity curve using a sample of…
Homogeneous Stellar Atmospheric Parameters and 22 Elemental Abundances for FGK Stars Derived From LAMOST Low-resolution Spectra with DD-Payne
Meng Zhang, Maosheng Xiang, Yuan-Sen Ting +11
A deep understanding of our Galaxy desires detailed decomposition of its stellar populations via their chemical fingerprints. This requires precise stellar abundances of many eleme…
Most Lithium-rich Low-mass Evolved Stars Revealed as Red Clump stars by Asteroseismology and Spectroscopy
Hong-Liang Yan, Yu-Tao Zhou, Xianfei Zhang +19
Lithium has confused scientists for decades at almost each scale of the universe. Lithium-rich giants are peculiar stars with lithium abundances over model prediction. A large frac…
High-resolution spectroscopy of the extremely iron-poor post-AGB star CC Lyr
Wako Aoki, Tadafumi Matsuno, Satoshi Honda +3
High-resolution optical spectroscopy was conducted for the metal-poor post-AGB star CC Lyr to determine its chemical abundances and spectral line profiles. Our standard abundance a…
Abundance Pattern Fitting with Bayesian Inference: Constraining First Stars' Properties and Their Explosion Mechanism with Extremely Metal-poor Stars
Ruizheng Jiang, Haining Li, Gang Zhao +2
The abundance patterns of extremely metal-poor stars preserve a fossil record of the Universe's earliest chemical enrichment by the supernova explosions from the evolution of first…
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…
The Stellar Abundances and Galactic Evolution Survey (SAGES) III -- The g/r/i-band Data Release
Chun Li, Zhou Fan, Gang Zhao +15
The Stellar Abundances and Galactic Evolution Survey (SAGES) is a multi-band survey that covers the northern sky area of ~12000 deg2. Nanshan One-meter Wide-field Telescope (NOWT)…
Four-hundred Very Metal-poor Stars studied with LAMOST and Subaru. I. Survey Design, Follow-up Program, and Binary Frequency
Wako Aoki, Haining Li, Tadafumi Matsuno +11
The chemical abundances of very metal-poor stars provide important constraints on the nucleosynthesis of the first generation of stars and early chemical evolution of the Galaxy. W…
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…
An Efficient Algorithm for Deep Stochastic Contextual Bandits
Tan Zhu, Guannan Liang, Chunjiang Zhu +2
In stochastic contextual bandit (SCB) problems, an agent selects an action based on certain observed context to maximize the cumulative reward over iterations. Recently there have…
Chasing the formation history of the Galactic metal-poor disc
Xiaokun Hou, Ruizhi Zhang, Haining Li +1
In our previous work, we identified metal-poor stars ([Fe/H] -1.0) from the LAMOST Survey. This work estimates their chemical abundances and explores the origin a…
Estimation of stellar atmospheric parameters from LAMOST DR8 low-resolution spectra with 20SNR30
Xiangru Li, Zhu Wang, Si Zeng +4
The accuracy of the estimated stellar atmospheric parameter decreases evidently with the decreasing of spectral signal-to-noise ratio (SNR) and there are a huge amount of this kind…
LAMOST Medium-Resolution Spectroscopic Survey (LAMOST-MRS): Scientific goals and survey plan
Chao Liu, Jianning Fu, Jianrong Shi +38
Since September 2018, LAMOST starts a new 5-year medium-resolution spectroscopic survey (MRS) using bright/gray nights. We present the scientific goals of LAMOST-MRS and propose a…
The Spectroscopic and Photometric Study of a Star Cluster Sample in Andromeda Halo
Hongrui Gu, Zhou Fan, Bingqiu Chen +18
Halo star clusters serve as vital tracers for the formation and evolution of the Andromeda galaxy. In this work, we present physical parameters for 29 M31 halo star clusters, deriv…