Search Publications
Class imbalance problem in short-term solar flare prediction
Wan, Jie; Fu, Jun-Feng; Liu, Jin-Fu +3 more
Using data-driven algorithms to accurately forecast solar flares requires reliable data sets. The solar flare dataset is composed of many non-flaring samples with a small percentage of flaring samples. This is called the class imbalance problem in data mining tasks. The prediction model is sensitive to most classes of the original data set during …
Precision of the Chinese Space Station Telescope (CSST) stellar radial velocities
Yuan, Hai-Bo; Sun, Yang; Deng, Ding-Shan
The Chinese Space Station Telescope (CSST) spectroscopic survey plans to deliver high-quality low-resolution (R > 200) slitless spectra for hundreds of millions of targets down to a limiting magnitude of about 21 mag, covering a large survey area (17 500 deg2) and a wide wavelength range (255-1000 nm by three bands GU, GV, and GI). I…
BESTP - An automated Bayesian modeling tool for asteroseismology
Gizon, Laurent; Jiang, Chen
Asteroseismic observations are crucial to constrain stellar models with precision. Bayesian Estimation of STellar Parameters (BESTP) is a tool that utilizes Bayesian statistics and nested sampling Monte Carlo algorithm to search for the stellar models that best match a given set of classical and asteroseismic constraints from observations. The com…
Spatially-resolved stellar population properties of the M51-NGC 5195 system from multi-wavelength photometric data
Kong, Xu; Zou, Hu; Lin, Lin +5 more
Using multi-band photometric images of M51 and its companion NGC 5195 from ultraviolet to optical and infrared, we investigate spatially resolved stellar population properties of this interacting system with stellar population synthesis models. The observed infrared excess (IRX) is used to constrain dust extinction. Stellar mass is also inferred f…
The stellar system HIP 101227: is it a binary, a triple or a quadruple system?
Annuar, Adlyka; Al-Wardat, Mashhoor; Yousef, Zahra Talal +4 more
In this paper, we present the analysis of the stellar system HIP 101227 to determine the actual number of components in the system, and their properties. We use dynamical modeling and complex spectrophotometric (involving atmospheric modeling) techniques with recent data, to determine the physical properties and orbital solution for the system, re…
The role of astronomical silicates during a cometary outburst
Wesołowski, Marcin
This paper presents a new approach to analyzing the change of cometary brightness. In our considerations, we assume that astronomical silicates (dust agglomerates) and gas are present in the coma. This assumption is a consequence of the analysis of the result observed during the Rosetta mission to comet 67P/Churyumov-Gerasimenko (abbreviated 67P/C…
Magneto-acoustic oscillations observed in a solar plage region
Cao, Wenda; Xu, Zhe; Ji, Kaifan +4 more
We gave an extensive study for the quasi-periodic perturbations on the time profiles of the line of sight (LOS) magnetic field in 10 × 10 sub-areas in a solar plage region (corresponds to a facula on the photosphere). The perturbations are found to be associated with the enhancement of He I 10830 Å absorption in a moss region, which is connected t…
Revisiting the formation mechanism for coronal rain from previous studies
Peter, Hardi; Chitta, Lakshmi Pradeep; Li, Le-Ping +1 more
Solar coronal rain is classified generally into two categories: flare-driven and quiescent coronal rain. Th latter is observed to form along both closed and open magnetic field structures. Recently, we proposed that some of the quiescent coronal rain events, detected in the transition region and chromospheric diagnostics, along loop-like paths cou…
The composite X-ray spectra of radio-loud and radio-quiet SDSS quasars
Gu, Min-Feng; Zhou, Min-Hua
We present a study of the X-ray emission for a sample of radio-detected quasars constructed from the cross-matches between SDSS, FIRST catalogs and XMM-Newton archives. A sample of radio-quiet SDSS quasars without FIRST radio detection is also assembled for comparison. We construct the optical and X-ray composite spectra normalized at rest frame 4…
LAMOST/HRS spectroscopic analysis of two new Li-rich giants
Pan, Kaike; Gao, Qi; Yan, Hong-Liang +9 more
Two Li-rich candidates, TYC 1338-1410-1 and TYC 2825-596-1, were observed by the new high-resolution echelle spectrograph, LAMOST/HRS. Based on their high-resolution and high-signal-to-noise ratio (SNR) spectra, we derived stellar parameters and abundances of 14 important elements for the two candidates. The stellar parameters and lithium abundanc…