Black hole X-ray binaries are bright accreting systems that can undergo apparent state changes on the reasonable timescales for human. These systems are good analogy to their supermassive counterparts: active galactic nuclei. X-ray reflection spectroscopy is a powerful tool to study the accretion geometry under different regimes. In this talk, I will present how we use X-ray reflection spectros...
Understanding the physics of the interstellar medium is critical for understanding star formation and AGN feedback. Line ratio diagnostics diagrams, such as BPT diagrams, have been extensively used to study the ISM. However, their limitations hide inaccuracies of photoionization models, leading to a number of discrepant results in the literature on metallicity, abundance pattern, and correlatio...
We develop a novel semi-analytic spectral fitting approach to quantify the star-formation histories (SFHs) and chemical enrichment histories (ChEHs) of individual galaxies. We construct simple yet general chemical evolution models that account for gas inflow and outflow processes as well as star formation, to investigate the evolution of merger-free star-forming systems. These models are fitted...
The halo stars on highly radial orbits should inevitably pass the center regions of the Milky Way, although they are hard to be detected from the crowded bulge/bar. Under the assumption that the stell...
Astrometry opened the era of modern astronomy/physics and plays a crucial role in contemporary astronomy, including the measurement of the three-dimensional structure of the Milky Way, black hole dete...