<p>In this project, we aim to understand structures in galaxies from a deconstructive perspective. In a series of papers, we have developed an accurate, efficient, and unsupervised way that extracts structures of simulated galaxies in kinematics. We successfully identify kinematically-derived bulge, disk, and halo structures that have clear physical formation mechanisms in the IllustrisTNG simulat...</p>
<p>As the witnesses of the early Universe, dwarf galaxies, especially the low-mass ones (total mass ≤ 10^9 M⊙), carry the imprint of essential physical processes, from the formation of the first stars to the formation of the first galaxies, which shaped the universe into the one we observe today. I will show the power of searching dwarf galaxy debris in the low-metallicity Milky Way, and how the...</p>
<p>One commonly accepted idea for the origin of the large-scale structure in the Universe is that the minute quantum fluctuations were stretched to macroscopic scales as a consequence of nearly exponential expansion of spacetime during the “cosmic inflation”. Cosmic inflation predicts primordial density fluctuations that are consistent with the observed CMB temperature fluctuations. It also pred...</p>
<p>Dark matter — established via various cosmological and astronomical observations — is a significant constituent of our Universe and remains one of the most outstanding mysteries of modern physics. The mass range of potential dark matter candidates covers more than 30 orders of magnitude. In the past, researchers have primarily focused on searching for GeV-TeV dark matter (WIMP) via nuclear re...</p>
<p>As fuel feeding supermassive black hole and star formation, cold molecular gas is the key to many fundamental processes in galaxy evolution. In the last decade and especially with the advent of Atacama Large Millimeter/submillimeter Array (ALMA), it has become feasible to spatially resolve giant molecular clouds (GMCs) in a large number and a wide variety of galaxies. Here, I summarise my work ...</p>
<p>The distance-inclination degeneracy limits gravitational-wave parameter estimation of compact binary mergers. Such a degeneracy can be partially broken by including higher-order modes or precession when modeling the waveform of a binary that contains a black hole. But what about binary neutron stars, for which these effects are suppressed? In this talk, I will introduce a new parameterization o...</p>
<p>As an important tracer of star formations and chemical enrichment in galaxies, HII regions play a fundamental role in our understanding of galaxy evolution. To infer the physical conditions of HII regions in galaxies, many diagnostic methods based on the emission-line spectra of the ionized gas have been proposed. Meanwhile, people have constructed theoretical models to describe the ionization ...</p>
<p>We present the results of a Damped Lyman α (DLA) system survey in the Dark Energy Spectroscopic Instrument (DESI) Survey Data release 1. The concordance DLA catalog combines the prediction from two fully automated techniques: the convolutional neural network (CNN) model and the Gaussian Process (GP) model. For each absorber, we obtain an accurate measurement of the redshift, the HI column dens...</p>
<p>Evolutions of stars, black hole accretion as well as interactions between stars and black holes play an important role in various astrophysical systems, such as supernova, X-ray binaries, AGNs as well as various transient phenomena. I will discuss some long standing issues related to massive star and black hole systems. Then I will describe some examples on how we can make progress on some of ...</p>
<p>LCDM is the standard model of modern cosmology with two dark components, dark matter and dark energy. The nature of dark energy and the dark matter structure growth rate can be probed via the large-scale structure (LSS). For this purpose, we observe millions of spectra of galaxies and quasars (QSOs) with spectroscopic galaxy surveys to explore the 3D map of the Universe. Meanwhile, high-resolut...</p>