Search Publications
On the Neutron Star/Black Hole Mass Gap and Black Hole Searches
Shao, Yong
Mass distribution of black holes in low-mass X-ray binaries previously suggested the existence of a ~2-5 M ⊙ mass gap between the most massive neutron stars and the least massive black holes, while some recent evidence appears to support that this mass gap is being populated. Whether there is a mass gap or not can potentially shed light…
Discovery of Extended Structure Around Open Cluster COIN-Gaia 13 Based on Gaia EDR3
Chen, Li; Zhong, Jing; Li, Jing +2 more
COIN-Gaia 13 is a newly discovered open cluster revealed by Gaia DR2 data. It is a nearby open cluster with a distance of about 513 pc. Combined with the five-dimensional astrometric data of Gaia EDR3 with higher accuracy, we use the membership assignment algorithm (pyUPMASK) to determine the membership of COIN-Gaia 13 in a large extended spatial …
Candidate Eclipsing Binary Systems with a δ Scuti Star in Northern TESS Field
Kahraman Aliçavuş, F.; Aliçavuş, F.; Ekinci, Ö. +4 more
The existence of pulsating stars in eclipsing binaries has been known for decades. These types of objects are extremely valuable systems for astronomical studies as they exhibit both eclipse and pulsation variations. The eclipsing binaries are the only way to directly measure the mass and radius of stars with a good accuracy (≤1%), while the pulsa…
A Possible 250 s X-Ray Quasi-periodicity in the Fast Blue Optical Transient AT2018cow
Tao, Lian; Zhang, Liang; Shu, Xinwen +11 more
The fast blue optical transients (FBOTs) are a new population of extragalactic transients of unclear physical origin. A variety of mechanisms has been proposed including failed supernova explosion, shock interaction with a dense medium, young magnetar, accretion onto a compact object and stellar tidal disruption event, but none is conclusive. Here…
A New X-Ray Tidal Disruption Event Candidate with Fast Variability
Greiner, J.; Komossa, S.; Erben, T. +3 more
During a close encounter between a star and a supermassive black hole, the star can get disrupted by the black hole's tidal forces, resulting in a tidal disruption event (TDE). The accretion of the star's material onto the black hole produces strong emission in different wavelength regimes. Here we report the discovery with the Roentgen Satellite …
Super-resolution of Solar Magnetograms Using Deep Learning
Xu, Long; Zhao, Dong; Dou, Fengping +2 more
Currently, data-driven models of solar activity forecast are investigated extensively by using machine learning. For model training, it is highly demanded to establish a large database which may contain observations coming from different instruments with different spatio-temporal resolutions. In this paper, we employ deep learning models for super…
The Role of Magnetic Fields in Triggered Star Formation of RCW 120
Chen, Zhiwei; Sefako, Ramotholo; Jiang, Zhibo +3 more
We report on the near-infrared polarimetric observations of RCW 120 with the 1.4 m IRSF telescope. The starlight polarization of the background stars reveals for the first time the magnetic field of RCW 120. The global magnetic field of RCW 120 is along the direction of 20°, parallel to the Galactic plane. The field strength on the plane of the sk…
Precise Evolutionary Asteroseismology of High-Amplitude δ Scuti Star AE Ursae Majoris
Fu, Jian-Ning; Xue, Hui-Fang; Niu, Jia-Shu
Stellar structure and evolution theory is one of the bases in modern astronomy. Stellar inner structures and their evolutionary states can be precisely tested by asteroseismology, since the inner information is brought to the stellar surface by the global oscillating waves and becomes observable. For stellar evolutionary speed (i.e., how long time…
The Relative Orientation between Local Magnetic Field and Galactic Plane in Low Latitude Dark Clouds
Wolf, S.; Pandey, J. C.; Choudhury, Gulafsha B. +4 more
In this work, we study the magnetic field morphology of selected star-forming clouds spread over the galactic latitude (b) range -10° to 10°. The polarimetric observations of clouds CB24, CB27 and CB188 are conducted to study the magnetic field geometry of those clouds using the 104 cm Sampurnanand Telescope (ST) located at ARIES, Manora Peak, Nai…
Physical Properties of 29 sdB+dM Eclipsing Binaries in Zwicky Transient Facility
Wang, Shu; Deng, Li-Cai; Wang, Kun +3 more
The development of large-scale time-domain surveys provides an opportunity to study the physical properties as well as the evolutionary scenario of B-type subdwarfs (sdBs) and M-type dwarfs (dMs). Here, we obtained 33 sdB+dM eclipsing binaries based on the Zwicky Transient Facility (ZTF) light curves and Gaia Early Data Release 3 (EDR3) parallaxes…