Research
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2023.04.19
Galaxy-Scale Strong Gravitational Lensing at High Angular Resolution
Anomalous flux ratios between lensed images can provide a key test of the dark matter sub-halo population, and hence the nature of dark matter. However, the observed anomalous flux ratios at radio frequencies can also be the result of systematics associated with our lack of knowledge about the source structure, source variability, propagation effects and microlensing of compact objects within t...
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2023.04.11
X-ray reflection spectroscopy on black hole X-ray binaries
Black hole X-ray binaries are bright accreting systems that can undergo apparent state changes on the reasonable timescales for human. These systems are good analogy to their supermassive counterparts: active galactic nuclei. X-ray reflection spectroscopy is a powerful tool to study the accretion geometry under different regimes. In this talk, I will present how we use X-ray reflection spectros...
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2023.06.30
Revealing the Recycled inflow of the massive galaxies at high redshift
The gas surrounding galaxies is known as the circumgalactic medium (CGM) which is considered to be deeply coupled with the evolution of galaxies. Although lots of works have been done, how galaxies co-evolve with the CGM is still poorly understood. To explore the CGM-galaxy ecosystem, especially the baryon cycle, we conduct observations on the high redshift CGM. First, we study the gas surroun...
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2023.06.16
Flow Annealed Kalman Filters: Gradient-free inference for expensive forward models
For many scientific applications the forward model consists of an expensive black-box simulator without easy access to gradients of the forward model. In such a situation, inference can be challenging, with standard gradient-free sampling algorithms requiring an intractably large number of serial model evaluations. In this talk I will introduce the flow annealed Kalman filter for approximate Ba...
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2023.06.09
3D Structure and Extinction of Nearby Molecular Clouds
The 3D structure and extinction law are studied for the Taurus, Orion, Perseus and California molecular clouds (MCs) based on the LAMOST and APOGEE spectroscopy. Extinctions are calculated from color excess derived from the Blue Edge methods. In combination with the distance from the Gaia, a 3D extinction map and the structure of these MCs can be retrieved and the clouds that overlap in the sk...
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