Search Publications
The spiral structure of the Milky Way
Xu, Ye; Hou, Li-Gang; Wu, Yuan-Wei
The morphology and kinematics of the spiral structure of the Milky Way are long-standing problems in astrophysics. In this review we firstly summarize various methods with different tracers used to solve this puzzle. The astrometry of Galactic sources is gradually alleviating this difficult situation caused mainly by large distance uncertainties, …
The SAGE photometric survey: technical description
Tan, Ke-Feng; Zhao, Gang; Fan, Zhou +4 more
To investigate a huge sample of data related to the Stellar Abundance and Galactic Evolution (SAGE) survey in more detail, we are performing a northern sky photometric survey named SAGES with the SAGE photometric system. This system consists of eight filters: Strӧmgren-u, SAGE-v, SDSS g, r, i, DDO-51, Hα wide and Hα narrow, i…
Machine learning classification of Gaia Data Release 2
Bai, Yu; Wang, Song; Liu, Ji-Feng
Machine learning has increasingly gained more popularity with its incredibly powerful ability to make predictions or calculate suggestions for large amounts of data. We apply machine learning classification to 85 613 922 objects in the Gaia Data Release 2, based on a combination of Pan-STARRS 1 and AllWISE data. The classification results are cros…
Physical and geometrical parameters of VCBS XIII: HIP 105947
Masda, Suhail Gumaan; Al-Wardat, Mashhoor Ahmed; Pathan, Jiyaulla Khan Moula Khan
The best physical and geometrical parameters of the main sequence close visual binary system (CVBS), HIP 105947, are presented. These parameters have been constructed conclusively using Al-Wardat’s complex method for analyzing CVBSs, which is a method for constructing a synthetic spectral energy distribution (SED) for the entire binary system usin…
The simplest way to get a cluster’s parameters in the Gaia era (Dolidze 41)
Tadross, Ashraf Latif
The astro-photometric parameters of the open star cluster Dolidze 41, which is located in the constellation Cygnus, have been investigated using the Gaia DR2 large survey that is merged with the near infrared Two Micron All Sky Survey (2MASS) database. The radial density distribution (limited, core and tidal radii), color-magnitude diagrams, galac…
High amplitude δ Scuti star BO Lyn with evidence of a late A-type companion in an elliptical orbit
Li, Lin-Jia; Qian, Sheng-Bang; Zhu, Li-Ying +2 more
We present 145 times of light maximum for high amplitude δ Scuti star BO Lyn based on several sky surveys (CRTS, DASCH, NSVS, OMC and SuperWASP) and our photometric observations. Combining with the data in literature, a total of 179 times of light maximum are used to analyze the O - C diagram of BO Lyn. We find that it can be described by an upwar…
A statistical study towards high-mass BGPS clumps with the MALT90 survey
Zhang, Chuan-Peng; Xu, Jin-Long; Liu, Xiao-Lan +2 more
In this work, we perform a statistical investigation towards 50 high-mass clumps using data from the Bolocam Galactic Plane Survey (BGPS) and Millimetre Astronomy Legacy Team 90-GHz survey (MALT90). Eleven dense molecular lines (N2H+(1-0), HNC(1-0), HCO+(1-0), HCN(1-0), HN13C(1-0), H13CO+…
The optical/UV excess of X-ray-dim isolated neutron star II. Nonuniformity of plasma on a strangeon star surface
Chen, Xuelei; Xu, Ren-Xin; Feng, Yi +4 more
Several X-ray-dim isolated neutron stars (XDINSs), also known as the Magnificent Seven, exhibit a Planck-like soft X-ray spectrum. In the optical/ultraviolet (UV) band, there is an excess of radiation compared to an extrapolation from the X-ray spectrum. However, the majority exhibits “spectral deviations”: the fact that there is more flux at long…
Global photometric analysis of Galactic HII regions
Kirsanova, Maria S.; Topchieva, Anastasiia; Wiebe, Dmitri
Total infrared fluxes are estimated for 99 HII regions around massive stars. The following wavebands have been used for the analysis: 8 and 24 µm, based on data from the Spitzer Space Telescope (IRAC and MIPS, respectively); 70, 160, 250, 350 and 500 µm, based on data from the Herschel Space Observatory (PACS and SPIRE). The estimated …
Manifestations of bright points observed in G-band and Ca II H by Hinode/SOT
Lin, Jun; Wu, Ning; Liu, Yan-Xiao
An algorithm was developed for identifying and tracking a magnetic bright point, or bright point (BP) for short, observed in both the photosphere (G-band) and chromosphere (Ca II H), as well as for pairing a photospheric BP (PBP) with its conjugate chromospheric BP (CBP). Two sets of data observed by Hinode/SOT in the quiet Sun near the disk cente…