A5073254170- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
Sun Yat-sen University
2023
University of Chinese Academy of Sciences
2019-2021
National Astronomical Observatories
2021
Chinese Academy of Sciences
2021
Abstract We identify member stars of more than 90 open clusters in the LAMOST survey. With method Fang et al., chromospheric activity (CA) indices, <?CDATA $\mathrm{log}{R}_{\mathrm{CaK}}^{{\prime} }$?> for 1091 82 and $\mathrm{log}{R}_{{\rm{H}}\alpha }^{{\prime} 1118 83 clusters, are calculated. The relations between average , each cluster its age investigated different T eff [Fe/H] ranges. find that CA starts to decrease slowly from log t = 6.70 8.50, then decreases rapidly until 9.53....
We report the discovery of emerged tidal tails around open cluster IC 4756 ($\sim$ 1 Gyr) based on 644 members identified from {\it Gaia} EDR3. Three-dimensional spatial positions, two-dimensional tangential velocities $\left( x, y, z, \kappa \cdot \mu_{\alpha}^{*}/\varpi, \mu_{\delta}/\varpi \right)$ are utilized to determine co-moving member candidates 4756. Using a Bayesian method, we correct distance for each member. Two extend up 180 pc and display S-shape in $X^{\prime}Y^{\prime}$...
We revisit the moving groups (MGs) in solar neighborhood with a sample of 91969 nearby stars constructed from LAMOST DR7. Using wavelet technique and Monte Carlo simulations, five MGs together new candidate located at $V \simeq$ -130 km s$^{-1}$ are detected simultaneously $V-\sqrt{U^2+2V^2}$ space. Taking into account other known MGs, we conclude that Galactic disk spaced by approximately 15 $\sim$ 25 along $V$ velocity. The origin is analysed through distributions [Fe/H]$-$[Mg/Fe] ages....
Abstract We identify 1325 member candidates of the open cluster (OC) Stock 2 using data from Gaia DR2. use algorithms Clusterix 2.0 and HDBSCAN to select further refine final membership by defining neighbors in 5D phase space ( X cp , Y <?CDATA ${Z}_{\mathrm{cp}},\kappa \cdot {\mu }_{\alpha }^{* }$?> / ϖ κ · μ δ ). Among these candidates, less than half have G BP RP extinctions Gaia. When are unavailable, we compute extiction empirical formulas E B − V ) = 0.350. analyze spatial distribution...
Abstract During the long term evolution of globular clusters (GCs), some member stars are lost to field. The recently found nitrogen-rich (N-rich) metal-poor field promising candidates these GC escapees, since N enhancement is fingerprint chemically enhanced populations in GCs. In this work, we discuss possibility identifying N-rich with upcoming Chinese Space Station Telescope (CSST). We focus on main survey camera NUV, u, g, r, i, z, y filters and slitless spectrograph a resolution about...
Abstract Using Gaia DR3 data and the wavelet transformation technique, we study substructures of Hercules moving group (HMG): 1 (H1) 2 (H2). Spectroscopic survey from LAMOST, APOGEE, GALAH are used to obtain metallicities ages stars belonging HMG. Our analysis leads several key findings as follows: (a) HMG is on average richer in metallicity than Galactic disk, with H2 being metal H1; (b) likely has a radial gradient distinct that disk; (c) older (d) age (e) distributions depend mainly...
We exploit the recent {\it James Webb Space Telescope} (JWST) determination of galaxy UV luminosity functions over redshift range $z=9-14.5$ to derive constraints on warm dark matter (WDM) models. The delayed structure formation in WDM universe makes high observations be a powerful probe set limits particle mass $m_\mathrm{x}$ candidates. By integrating these with blank-field surveys conducted by Hubble (HST) at redshifts $z=4-8$, we impose both astrophysical and parameters simultaneously....
The determination of atmospheric parameters white dwarf stars (WDs) is crucial for researches on them. Traditional methodology to fit the model spectra observed absorption lines and report with lowest $\chi ^2$ error, which strongly relies theoretical models that are not always publicly accessible. In this work, we construct a deep learning network model-independently estimate Teff log g DA (DAs), corresponding WDs hydrogen dominated atmospheres. directly trained tested normalized flux...
We construct a sample of nearly 30,000 main-sequence stars with 4500 K < Teff 5000 and stellar ages estimated by the chromospheric activity−age relation. This is used to determine age distribution in R–Z plane Galaxy, where R projected Galactocentric distance disk midplane Z height above midplane. As ∣Z∣ increases, percentage old becomes larger. It known that scale-height Galactic increases as which called flare. A mild flare from ∼ 8.0 9.0 kpc found. also find velocity dispersion confirmed...
We present a new moving group clustered in kinematics, spatial position, and elemental abundances. Its position is around the center of Local Arm Milky Way. A convergent point method was taken to select candidate member stars. Among 206 stars, 74 are pre-main-sequence stars some them have stellar disks. presume those belong Orion nebula. suggest that this caused by density wave passing by.