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2024.04.18

Illuminating the Cosmic Web and the Circumgalactic Medium with the help of quasars

<p>Our standard cosmological model predicts that most of the matter in the universe is distributed into a network of filaments - the Cosmic Web - in which galaxies form and evolve. Because most of this material is too diffuse to form stars, its direct detection in emission has remained elusive for several decades leaving fundamental questions still open, including: How are galaxies linked to each ...</p>

2024.04.11

The impact of massive stars and black holes on the dynamical evolution of star clusters

<p>Massive stars have a significant impact on the dynamical evolution of star clusters. They play a crucial role during star formation, as their radiation can push surrounding gas away and inhibit further star formation. Additionally, strong mass loss from massive stars via strong winds can rapidly reduce the gravitational potential of star clusters and trigger their fast expansion. Once these mas...</p>

2024.03.28

A polarized view of the pulsar wind nebulae with IXPE

<p>Pulsar wind nebulae (PWNe) are powerful sources of non-thermal X-ray radiation, which is intrinsically polarized due to synchrotron emission. The magnetic field strength and structure in these sources play a crucial role in shaping their dynamics, energetics and evolution, as well as in accelerating particles to very high energies. X-ray polarimetry can provide unique insights into understandin...</p>

2024.03.21

Interstellar X-ray Dust Scattering: Current Research and Future Prospects

<p>Our Universe is pervaded with X-ray sources. When X-ray photons traverse through interstellar space, they can be scattered by dust particles floating in space, producing scattering rings and halos around X-ray sources. This scattering effect can be used to study the distribution of interstellar dust, as well as the size distribution, composition and structure of dust grains. It also affects the...</p>

2024.03.14

A hydrodynamic study of the atmospheric escape of the hot Jupiter WASP-121b

<p>The escape of the atmosphere plays a crucial role in planetary evolution. Recent advancements in high spectral resolution transmission spectrum observation have provided an exceptional opportunity to investigate the structure of exoplanet upper atmospheres and their escape processes. In this talk, I will introduce a sophisticated forward model by expanding the capability of a one-dimensional mo...</p>

2024.03.07

Galaxy-halo connection and near-field cosmology with numerical and semi-analytic methods

<p>In our modern understanding of the Universe, dark matter (DM) constitutes ~85% of the total mass and forms gravitationally bound halos which are the sites for galaxy formation. Galaxies contain information of their host halos, and halos react to the baryonic processes of the inhabitant galaxies — their connections are essential for understanding galaxy formation, and enable us to derive fundam...</p>

2024.01.12

Ultra-compact dwarf galaxies caught in the act of transformation

<p>In the past two decades, systematic studies have revealed hundreds of ultra-compact dwarf galaxies (UCDs) in the nearby Universe. While similar in appearance to massive globular clusters, the detection of extended stellar envelopes, complex star formation histories, elevated mass-to-light ratio, and supermassive black holes suggest that some UCDs are remnant nuclear star clusters of tidally-str...</p>

2024.01.09

Exploring the new high-redshift frontier with the James Webb Space Telescope

<p>The advent of the James Webb Space Telescope (JWST) has brought the study of early galaxy formation to a new level. Shortly after it began its scientific operation, JWST revealed a large number of candidate galaxies at redshift (z) greater than 11 when the universe was less than ~420 million years old, some of which could even be at z ~ 20 (age of the universe ~180 million years). This was comp...</p>

2024.01.05

The circumnuclear gas in M81: a unique testbed for AGN and stellar photoionization

<p>The origin of the low-ionization nuclear emission-line region (LINER) prevalent in local galaxies and its relationship with supermassive black holes are debated for decades. We preform a comprehensive evaluation of traditional photoionization models against the circumnuclear ionized gas in M81, for which recent CAHA/PPAK integral-field spectroscopic observations reveal a LINER characteristic ou...</p>

2024.01.02

Expanding our perspective to the distant universe through Intensity Mapping of HI and CII

<p>As a prevalent and widely distributed component of galactic gas, neutral atomic hydrogen (HI) and Carbon lines (CO, CII) play a crucial role in comprehending various astrophysical processes, including star formation histories, galaxy interactions, and the tracing of cosmic large-scale structures. However, the sensitivity limitations of telescopes pose challenges to directly measuring line signa...</p>