Search Publications

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…

Evaluating Helium Variations By Modeling Red Giant Branch Bump of Large Magellanic Cluster NGC 1978

Li, Cheng-Yuan; Ji, Xin; Deng, Li-Cai

Many evidences show that the Multiple Population (MP) features exist not only in old clusters but also in intermediate-age clusters in the Megallanic Clouds (MCs), which are characterized by star-to-star abundance scatter of several elements, including helium (He). The red giant branch bump (RGBB)'s photometric properties are proved to be related …