A5087609791- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Perovskite Materials and Applications
- Astro and Planetary Science
- Physics of Superconductivity and Magnetism
- Astronomical Observations and Instrumentation
- Advanced Condensed Matter Physics
National Astronomical Observatories
2022-2023
University of Chinese Academy of Sciences
2020-2023
In this paper, we report 591 high velocity star candidates (HiVelSCs) selected from over 10 million spectra of the data release seven (DR7) Large Sky Area Multi-object Fiber Spectroscopic Telescope and second Gaia release, with three-dimensional velocities in Galactic rest-frame larger than 445 km/s. We show that at least 43 HiVelSCs are unbound to Galaxy escape probabilities 50%, number decreases eight if possible parallax zero-point error is corrected. Most these metal-poor slightly...
Abstract We derive a catalog of early-type emission-line stars including 30,023 spectra 25,867 from LAMOST Data Release 7, in which 4189 have Simbad records. The are classified into three morphological types (10 subtypes) based on H α profiles. Some contaminated by nebula emission lines such as ii regions flagged the catalog. also provide specific 20 with stellar winds or accretion flows calculating terminal and peak velocities P-Cygni inverse More important, two color–color diagrams, (H-K s...
Abstract In this paper, we report on 606 S-type stars identified from Data Release 9 of the LAMOST medium-resolution spectroscopic (MRS) survey; 539 them are reported for first time. The discovery these is a three-step process, i.e., selecting with ZrO-band indices greater than 0.25, excluding non-S-type iterative Support Vector Machine method, and finally retaining absolute bolometric magnitude larger −7.1. consistent distribution known in color–magnitude diagram. We estimated C/Os using...
In this paper, we found 2939 S-type stars from LAMOST Data Release 10 using two machine-learning methods, and 2306 of them were reported for the first time. The main purpose work is to study how divide into intrinsic extrinsic with photometric data spectra. Using infrared data, adopted methods distinguish stars, i.e., XGBoost algorithm color-color diagrams. We trained model 15 input features consisting colors absolute magnitudes Two Micron All Sky Survey (2MASS), AllWISE, AKARI, IRAS, that...
Abstract We perform 23 Na nuclear magnetic resonance (NMR) and magnetization measurements on an S = 1, quasi-2D honeycomb lattice antiferromagnet 3 Ni 2 BiO 6 . A large positive Curie–Weiss constant of 22.9 K is observed. The NMR spectra at low fields are consistent with a zigzag order, indicating easy-axis anisotropy. With the field applied along c * axis, confirm existence 1/3-magnetization plateau phase between 5.1 T 7.1 T. transition from order to also found be first-order type....
Abstract In this paper, we developed a spectral emulator based on the Mapping Nearby Galaxies at Apache Point Observatory Stellar Library (MaStar) and grouping optimization strategy to estimate effective temperature ( T eff ), surface gravity (log g metallicity ([Fe/H]), abundance of alpha elements with respect iron ([ α /Fe]) for O-M-type stars within Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) low-resolution spectra. The primary aim is use rapid spectral-fitting...
Abstract We identify 20 F-type Herbig stars and provide a list of 22 pre-main-sequence candidates from LAMOST DR8. The effective temperature, distance, extinction, stellar luminosity, mass, age, radius are derived for each star based on optical spectra, photometry, Gaia EDR3 parallaxes, evolutionary tracks. According to spectral energy distribution, 19 belong Class II YSOs, one belongs the flat-spectrum class. Four have Spitzer IRS which three show extremely weak polycyclic aromatic...