Search Publications
Application of Random Forest Regressions on Stellar Parameters of A-type Stars and Feature Extraction
He, Ying; Chen, Shu-Xin; Sun, Wei-Min
Measuring the stellar parameters of A-type stars is more difficult than FGK stars because of the sparse features in their spectra and the degeneracy between effective temperature (T eff) and gravity (log g). Modeling the relationship between fundamental stellar parameters and features through machine learning is possible because we can …
Herschel Investigation of Cores and Filamentary Structures in the Perseus Molecular Cloud
Zhang, Guo-Yin; Zhang, Chang; Li, Jin-Zeng +1 more
Cores and filamentary structures are the prime birthplaces of stars, and play key roles in the process of star formation. Latest advances in the methods of multi-scale source and filament extraction, and in making high-resolution column density map from Herschel multi-wavelength observations enable us to detect the filamentary network structures i…
A Photometric Study of Two Contact Binaries: CRTS J025408.1+265957 and CRTS J012111.1+272933
Hu, Qingshun; Zhang, Yu; Ma, Shuo +2 more
We performed new photometric observations for two contact binaries (i.e., CRTS J025408.1+265957 and CRTS J012111.1+272933), which were observed by the 1.0 m telescope at Xingjiang Astronomical Observatory. From our light curves and several survey data, we derived several sets of photometric solutions. We found that CRTS J025408.1+265957 and CRTS J…
X-Ray and Radio Studies of the Candidate Millisecond Pulsar Binary 4FGL J0935.3+0901
Zheng, Dong; Wang, Zhong-Xiang; Xing, Yi +1 more
4FGL J0935.5+0901, a γ-ray source recently identified as a candidate redback-type millisecond pulsar (MSP) binary, shows an interesting feature of having double-peaked emission lines in its optical spectrum. This feature would further suggest the source is a transitional MSP system in the sub-luminous disk state. We have observed the source with X…
Photometric Investigation of Contact Binary DY Cet Based on TESS Data
Yıldırım, M. F.
We present a photometric analysis of the Transiting Exoplanet Survey Satellite (TESS) light curve of contact binary system DY Cet and the behavior of its orbital period variation. The light curve and published radial velocity data analysis was performed using the Wilson-Devinney code. As a result of simultaneous analysis of the light curve with ra…
Can Turbulent, High-density Gas Form Stars in Molecular Clouds: A Case Study in Ophiuchus
Tsai, Chao-Wei; Lin, Yuxin; Wu, Jingwen +3 more
Star formation is governed by the interplay between gravity and turbulence in most of molecular clouds. Recent theoretical works assume that dense gas, whose column density is above a critical value in the column density probability distribution function (N-PDF), where gravity starts to overcome turbulence, becomes star-forming gas and will collap…
The Distribution of UV Radiation Field in the Molecular Clouds of Gould Belt
Li, Di; Xie, Jinjin; Fuller, Gary A. +5 more
The distribution of ultraviolet (UV) radiation field provides critical constraints on the physical environments of molecular clouds. Within 1 kpc of our solar system and fostering protostars of different masses, the giant molecular clouds in the Gould Belt present an excellent opportunity to resolve the UV field structure in star-forming regions. …
Revisiting the Evidence for an Intermediate-mass Black Hole in the Center of NGC 6624 with Simulations
Wang, Li-Chun; Xie, Yi
The acceleration of LMXB 4U 1820-30 derived from its orbital-period derivative ${\dot{P}}_{{\rm{b}}}$ was supposed to be the evidence for an Intermediate-mass black hole (IMBH) in the Galactic globular cluster (GC) NGC 6624. However, we find that the anomalous ${\dot{P}}_{{\rm{b}}}$ is mainly due to the gravitational wave emission, rather than the…
Precise Positions of Triton in 2010-2014 based on Gaia-DR2
Yu, Yong; Tang, Kai; Zhang, Huiyan +2 more
With unique orbital and physical characteristics, Triton is a very important target because it may contain information of the origin and evolution of the solar system. Besides space explorations, ground-based observations over long time also play a key role on research of Triton. High-precision positions of Triton obtained from ground telescopes a…
New Massive Contact Twin Binary in a Radio-quiet H II Region Associated with the M17 Complex
Chen, Zhiwei; Jiang, Zhibo; Yin, Jia +3 more
Early-B stars, much less energetic than O stars, may create an H II region that appears as radio-quiet. We report the identification of new early-B stars associated with the radio-quiet H II region G014.645-00.606 in the M17 complex. The radio-quiet H II region G014.645-00.606 is adjacent to three radio-quiet WISE H II region candidates. The ioniz…