Search Publications
LAMOST Medium-resolution Spectroscopic Survey of Galactic Open Clusters (LAMOST-MRS-O): An Overview of Survey Plan and Preliminary Results
Shi, Jianrong; Chen, Li; Zhang, Xi +8 more
As part of the LAMOST medium-resolution spectroscopic survey, the LAMOST-MRS-O is a non-time domain survey that aims to perform medium-resolution spectral observations for member stars in the open cluster areas. This survey plans to obtain the spectroscopic parameters such as radial velocity and metal abundances of member stars and provide data su…
Sympathetic Solar Eruption on 2024 February 9
Feng, Li; Li, Shu-Yue; Zhang, Qing-Min +4 more
In this paper, we perform a follow-up investigation of the solar eruption originating from active region 13575 on 2024 February 9. The primary eruption of a hot channel generates an X3.4 class flare, a full-halo coronal mass ejection (CME), and an extreme-ultraviolet (EUV) wave. Interaction between the wave and a quiescent prominence (QP) leads to…
Photometric Metallicities of 0.8 Million KiDS Stars
Chen, Bing-Qiu; Liu, Xiao-Wei; Sun, Bao-Kun
Accurate determinations of metallicity for large, complete stellar samples are essential for advancing various studies of the Milky Way. In this paper, we present a data-driven algorithm that leverages photometric data from the KiDS and the VIKING surveys to estimate stellar absolute magnitudes, effective temperatures, and metallicities. The algor…
A Multi-faceted View of the X-Ray Spectral Variability in Seyfert Galaxy Ark 120
Kang, Jia-Lai; Wang, Jun-Xian; Ren, Lu-Xin
Utilizing a range of techniques including multi-band light curves, softness ratio analysis, structure functions, rms spectra, cross-correlation functions, and ratios of spectra from different intervals, we present a comprehensive study of the complex X-ray spectral variability in Seyfert 1 galaxy Ark 120, through re-analyzing its six XMM-Newton ob…
Long-period Double-lined Eclipsing Binaries: The System V454 Aur with the Secondary Eclipse Caused by the Occultation of the Hotter Component
Kniazev, Alexei Y.; Malkov, Oleg; Berdnikov, Leonid N. +2 more
We present the results of our study of the long-period eclipsing binary star V454 Aur. The results are based on spectroscopic data obtained with the UFES échelle spectrograph and photometric observations from Transiting Exoplanet Survey Satellite (TESS). The derived radial velocity curve is based on 17 spectra obtained between 2021 and 2023, cover…
New Orbital Parameters of 850 Wide Visual Binary Stars and Their Statistical Properties
Izmailov, Igor; Khovritchev, Maxim
Based on positional observations and measurements of radial velocities, the orbits of 850 wide visual binary stars have been determined. The parameters of the log-normal distributions for the histograms of orbital periods, stellar masses, and semimajor axes in astronomical units have been obtained. The eccentricity histogram for binary stars with …
Modified Masses and Parallaxes of the Close Visual Triple System HD 2893
Masda, Suhail; Al-Wardat, Mashhoor; Aljboor, Hussam +4 more
We present the essential stellar parameters of the close visual triple system HD 2893 using Al-Wardat's method for analyzing binary and multiple star systems in conjunction with Kurucz's model atmospheres. This method accurately computes the spectrophotometric stellar masses through a combined synthetic spectral energy distribution approach that c…
Implications of the Stellar Mass Density of High-z Massive Galaxies from JWST on Warm Dark Matter
Gong, Yan; Chen, Xuelei; Lin, Hengjie +1 more
A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope (JWST), and it may require a high star formation efficiency. However, this will lead to large number density of ionizing photons in the epoch of reionization (EoR), so that the reionization history will be…
Two-dimensional Parameter Relationships for W UMa-type Systems Revisited
Poro, Atila; Paki, Ehsan; Hedayatjoo, Mahya +6 more
Reviewing the empirical and theoretical parameter relationships between various parameters is a good way to understand more about contact binary systems. In this investigation, two-dimensional (2D) relationships for P-M V(system), P-L 1,2, M 1,2-L 1,2, and q-L ratio were revisited. The sample…
Quantifying the Tension between Cosmological Models and JWST Red Candidate Massive Galaxies
Wang, Jun-Chao; Huang, Zhi-Qi; Huang, Lu +1 more
We develop a Python tool to estimate the tail distribution of the number of dark matter halos beyond a mass threshold and in a given volume in a light-cone. The code is based on the extended Press–Schechter model and is computationally efficient, typically taking a few seconds on a personal laptop for a given set of cosmological parameters. The hi…