Cosmic reionization is the last major phase transition that our Universe goes through. In this milestone, the intergalactic medium transitions from primarily neutral, dark, and cold into mainly ionized, more luminous, and warmer. However, as exciting as the reionization process surely was, many aspects remain unknown, e.g. what are the sources of the ionizing photons? or what is the timeline of...
Most galaxies comparable to or larger than the mass of the Milky Way host hot, X-ray emitting atmospheres and central radio sources. Hot atmospheres and radio jets and lobes are the ingredients of radio-mechanical active galactic nucleus (AGN) feedback. About half of the most massive early type galaxies harbour multi-phase filamentary gas, which appears to result from the thermally unstable coo...
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...
Modern cosmology is an observational driven science. Two dark components, dark matter and dark energy, are introduced to explain the invisible mass inferred from various astrophysical observations and the accelerated expansion of the Universe. They represent around 95% of the total mass-energy budget of the Universe today. However, little is known about their nature.As a result of the competiti...
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 ...