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2022.12.01

Unveiling the astrophysics of cosmic reionization in the post-reionization era

<p>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...</p>

2022.11.24

Multi-phase gas, accretion, and mechanical AGN feedback in early-type galaxies

<p>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...</p>

2022.11.03

"brown dwarfs, are we stupid or you are just different?"

<p>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...</p>

2022.11.17

Cosmology with spectroscopic surveys

<p>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...</p>

2022.11.10

Space-based Wide-field Slitless Spectroscopy and Near-Ultraviolet Imaging

<p>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 ...</p>

2022.10.27

Towards precise calibrations of wide-field surveys in the era of LAMOST and Gaia

<p>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)&nbsp; 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...</p>

2022.10.20

Multi-faceted Views of Planetary Systems

<p>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 ...</p>

2022.10.13

Cosmology with Massive Neutrinos

<p>Ghostly neutrino particles continue to bring surprises to fundamental physics, from their existence to the phenomenon of neutrino oscillation, which implies their nonzero masses. Their exact masses, among the most curious unknowns beyond the Standard Model of particle physics, can soon be probed by the joint analysis of upcoming cosmological surveys including the CSST, Rubin Observatory LSST, P...</p>

2022.09.29

Computational Imaging for Astronomy: from Exoplanets to Black Holes

<p>Recent development in computational imaging has led to a series of great discoveries in astronomy. Integrated with advanced computational tools, modern telescopes continue pushing the boundaries of astronomical imaging, making it possible to observe many scientific phenomena in extreme conditions. In this talk, I will introduce a series of innovative computational imaging tools we have develope...</p>

2022.09.22

Black Hole and Magnetar Studies with the Imaging X-ray Polarimetry Explorer

<p>The Imaging X-ray Polarimetry Explorer (IXPE) mission was launched on December 9, 2021 and has observed a number of galactic and extragalactic X-ray sources. I report here on the IXPE observations of the High Mass X-Ray Binary Cyg X-1. IXPE detected a strong 2-8 keV polarization signal constraining the origin of the X-ray emission and the configuration of matter close to the Cyg X-1 black hole....</p>