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...
In this talk, the speaker will briefly review the observing modes of wide-field slitless spectroscopy and near-ultraviolet (NUV) imaging, enabled by the cutting-edge instruments on board current space telescopes, i.e. the Hubble Space Telescope (HST) and the James Webb Space Telescope (JWST). He will first introduce the multiple observing programs that acquired deep near-infrared grism and NUV ...
Brown dwarfs are the latest discovered population on the HR diagram. They formed like stars but appearing like gaseous planets, thus bridging the gap between stars and planets. I will briefly introduce the research history of brown dwarfs and summarize the properties of known brown dwarfs. Then, I will explain the new discovered substellar transition zone formed by transitional brown dwarfs, an...
Uniform and precise calibration plays an important role in the current and next-generation surveys. In this talk, I will discuss challenges and opportunities of 1) photometric calibration of wide-field photometric surveys, 2) wavelength calibration of spectroscopic surveys, and 3) flux calibration of slitless spectroscopic surveys in the era of LAMOST and Gaia.BIO2015-Present: Associated Profe...
Over the past couple decades, thousands of extra-solar planets have been discovered orbiting other stars. The exoplanets discovered to date exhibit a wide variety of orbital and compositional properties; most are dramatically different from the planets in our own Solar System. Our classical theories for the origins of planetary systems fail to account for the diversity of planets now known. In ...