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2025.02.18

面向天文观测和深空探测的光电探测技术 [中文报告]

<p>天文及深空科学是主要由实测驱动的学科。观测设备的实测精度和能力的显著提高会大大促进人类对宇宙的认知，包括21世纪所面临的几个重大挑战包括暗物质、暗能量研究，高红移宇宙，以及外行星和生命起源。这些重大科学问题的攻克、前沿研究的突破性进展，已经越来越依赖于观测设备能力的不断提升，包括提高观测的灵敏度、谱分辨率、时间分辨率、角分辨率以及拓展波段覆盖区域。这些观测设备就需要功能强大性能卓越的焦面仪器系统...</p>

2025.03.06

Galaxy quenching from the perspective of semi-analytic model GAEA

<p>Galaxy quenching is a crucial phase of galaxy evolution. For years the over-quenching problem has posed a big challenge to galaxy evolution models at low redshift. In this talk, I will introduce how we improve the semi-analytic model GAEA step-by-step to reproduce the observed quenched fractions, and the lessons we learned. Then we apply this model to high redshift to understand the galaxy quen...</p>

2025.01.06

Decoding binary neutron stars with the next-generation gravitational wave detectors: localization, parameter estimation, and equations of state

<p>Gravitational waves (GWs) from binary neutron stars (BNSs) offer valuable understanding of the nature of compact objects and hadronic matter. However, the analyses accompanied require massive computational power due to the difficulties in Bayesian stochastic sampling. The third-generation (3G) GW detectors are expected to detect BNS signals with significantly extended signal duration, detection...</p>

2024.12.24

Uncovering Early Galaxy Formation with JWST: A Modeling Perspective

<p>The James Webb Space Telescope (JWST) is transforming our understanding on galaxy formation and evolution, revealing distant galaxies deep into the epoch of reionization and uncovering red sources that were simply unknown pre-JWST. In this talk, I will discuss two key areas, with a focus on the challenges in modeling the spectral energy distributions in the JWST era. First, a central science go...</p>

2024.11.21

On the Formation, Evolution and the Environment of Low Surface Brightness Galaxies [EN]

<p>The variations in the size of galaxies, and consequently, the formation of Low Surface Brighntess Galaxies (LSBGs) could be followed from one of two different effects: variations in the spin parameter of the halo (λ) or variations in the density of dark matter halos (McGaugh 2021). We test both scenarios by employing a simulated sample of galaxies drawn from the TNG100 run of the IllustrisTNG ...</p>

2024.11.20

[PDS seminar] The instability mechanism of compact multiplanet systems [EN]

<p>Numerical integrations of Kepler-like tightly packed planetary systems show that they are chaotic, with fairly short Lyapunov times, but that they can be stable against planet-planet or planet-star collisions for billions of years. Recent work by Petit et al. showed that this behavior was due to the overlap of three-body mean motion resonances. Caleb Lammers, Sam Hadden and I recently showed th...</p>

2024.10.22

Mapping the 3D Universe: From the Past to the Future, Bridging Theories and Observations

<p>This collaborative talk introduces the recent work in COSMO-3D group at EPFL’s Laboratory of Astrophysics (LASTRO). Jiaxi Yu (PhD student) will begin with a historical review of cosmology. The Universe started from a Big Bang, followed by inflation. The emission of the first light of the Universe, cosmic microwave background (CMB), happened in an opaque and dark era of the Universe afterwards....</p>

2024.09.04

Comprehensive population synthesis predictions for massive binary stars in the Small Magellanic Cloud

<p>The past and ongoing gravitational wave detections have fostered a wide interest in understanding the formation of binary black holes (BBHs). Several formation scenarios have been proposed, including the evolution of isolated massive binaries. While most of the observed merging black holes are at cosmological distances, and thus likely at low metallicity, the Small Magellanic Cloud (SMC) provid...</p>

2024.09.05

A precise measurement of the supermassive black hole mass in the galaxy NGC 383 using molecular gas kinematics down to the circumnuclear disc

<p>I will present a measurement of the supermassive black hole (SMBH) mass in NGC 383, a nearby lenticular galaxy hosting a low-power radio jet, based on ALMA observations of the CO(2-1) emission line with an angular resolution of 0.′′050 × 0.′′024 (≈ 16 pc × 8 pc). These observations spatially resolve the nuclear molecular gas disc down to ≈ 41300 Schwarzschild radii and the SMBH sphere of...</p>

2024.09.05

Deep Synoptic Array and FRB

<p>Fast radio bursts (FRBs) are typically milli-second-duration luminous radio transients whose source remain debatable. &nbsp;Caltech/ OVRO&#39;s Deep Synoptic Array-110 (DSA-110) is the only radio interferometer designed specifically for FRB searching and localization. &nbsp;By mid-2023, DSA-110 has doubled the number of localized FRBs. &nbsp;First, I will highlight the high-resolution burst morphology of a sample...</p>