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2023.05.11

Physical Mechanisms Regulating Gas Supply to Galaxies

<p>I will first present an overview of the problem of galaxy formation. I will then turn my attention to some important and robust physical mechanisms that regulate the supply of cold gas to galaxies. I will in the end try to convey the message that the field of galaxy formation simulation would benefit by turning to more physics, rather than parameter, based approach, through exploring additional...</p>

2023.04.27

Formation of hot Jupiters in star clusters

<p>It has been suggested that the occurrence rate of hot Jupiters (HJs) in&nbsp;some open clusters might reach several per cent, significantly higher&nbsp;than that of the field. Several models have been proposed to solve this&nbsp;problem but none has been satisfactory. In a binary-rich cluster, the&nbsp;von Zeipel-Lidov-Kozai (ZKL) mechanism may cause the observed high&nbsp;occurrence rate. For planets formed around a s...</p>

2023.04.20

The gas environment of galaxies across 10 billion years

<p>The evolution of galaxies is closely connected to the gas environment in which galaxies reside. Traditionally, this tenuous gas that cycles in and out of galaxies has been studied primarily in absorption using quasar spectroscopy. The deployment of large integral field spectrographs at 8 meter telescopes, and in particular MUSE at VLT, has transformed our view of the interplay between the ambie...</p>

2023.04.13

Coronal magnetic field Measurements

<p>Coronal magnetic fields are at the heart of most of the unsolved problems in solar physics and of the solar–terrestrial relationship. However, no routine measurements have been carried out for the magnetic field measurement in the solar corona, due to the weakness of its signature. In the past several decades, a number of techniques have been developed for coronal magnetic field diagnostics. I...</p>

2023.04.06

Solving the Mystery of Small Exoplanets through Holistic Characterization

<p>The first detection of another planet around a Sun-like star marked the beginning of a new era in which our understanding of how planets typically form and the uniqueness of our Solar System were radically upended. We now know that planet formation is incredibly resilient, and produces a diverse myriad of planets around a wide range of stellar types. These remarkable findings tell us that the S...</p>

2023.03.30

Not only astrophysics: fundamental physics studies with high energy missions

<p>There are no doubts that high energy astrophysics has opened new views on the Universe and on the many classes of sources that populates the hot and energetic sky. However, in the near future, spectral, timing, and polarimetric observations at high energies are expected to address key scientific questions in fundamental physics.In this seminar, I will first briefly summarise the potential of hi...</p>

2023.03.23

Active Galactic Nuclei: Monsters to Scale or Puzzles to Solve?

<p>Active Galactic Nuclei (AGNs) are the brightest sources of electromagnetic radiation in the&nbsp;universe, enabling us to observe them across the cosmos. AGNs are the central parts of galaxies.Most of their brightness results from the accretion of matter by a supermassive black hole&nbsp;(SMBH) at their center. Studying the AGNs informs us about the role of SMBHs in the&nbsp;formation and evolution of galaxie...</p>

2023.03.09

Re-investigating A Puzzle in Kepler Planets

<p>super-Earths and mini-Neptunes (shortened as &#39;kepler planets&#39;) are the most abundant type of planets known to us. Currently, their formation channel is under debate.In this talk, I will discuss our attempt to solve a small puzzle in the observations of these planets. We were led to claim that, after formation, each of these planets have scattered and digested a few Mars-massed objects. The smal...</p>

2023.03.16

Microphysical and non-thermal processes in the circumgalactic medium: turbulence, magnetic fields and cosmic rays

<p>Multiphase gas structure is ubiquitous in our universe. Recent observations suggest that large quantities of cool (10^4 K) gas are detected in the circumgalactic medium (CGM) of galaxy halos, which extends up to a few times of galactic virial radius. In addition, warm gas at a few 10^5 K is found to be tightly associated with the star-forming galaxies, but not the quenched ones. However, the or...</p>

2023.03.02

The variation of the stellar initial mass function (IMF) with metallicity and time

<p>The stellar IMF is one of the most important astrophysical distributions and plays vital role in galactic astronomy. Both constant and variable IMFs across different environments have been claimed despite a large number of theoretical and observational efforts. However, the measurement of the IMF in Galactic stellar populations has been limited by the relatively small number of photometrically ...</p>