科学研究
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2023.12.05
Reconstruction of Cosmological Initial Density Field with Observations from the Epoch of Reionization
Initial density distribution provides a basis for understanding the complete evolution of cosmological density fluctuations. While reconstruction in our local Universe exploits the observations of galaxy surveys with large volumes, observations of high-redshift galaxies are performed with a small field of view and therefore can hardly be used for reconstruction. Here we propose to reconstruct t...
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2023.11.21
A two-phase model of galaxy formation: the growth of galaxies and supermassive black holes
I will describe a model for galaxy formation and the growth of supermassive black holes (SMBHs), based on the fact that cold dark matter halos form their gravitational potential wells through a fast phase with rapid change in the potential, and that the high universal baryon fraction makes cooled gas in halos self-gravitating and turbulent before it can form rotation-supported disks. Gas fragme...
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2023.11.14
The star formation, dust, and abundance of galaxies with CIB cross-correlations
The cosmic infrared background (CIB) is the accumulated infrared radiation mainly generated from dust emissions in star-forming galaxies. It bears rich information about star formation history, dust thermodynamics, and galaxy abundance in the distant Universe. The CIB auto- and cross-correlations with other large-scale structure (LSS) tracers have been used to probe the star formation, dust, an...
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2023.10.31
Surveying galaxy clusters in the X-ray Universe: New results from eROSITA
The eROSITA X-ray telescope has performed four X-ray all-sky surveys since its launch in July 2019. In this talk, I will briefly overview eROSITA's early results on galaxy clusters, with an emphasis on the eFEDS PV-phase program. I will also report the latest progress on clusters and superclusters from the first eROSITA All-Sky Survey.BIODr. Ang Liu is a postdoc researcher at Max Planck Institu...
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2023.10.30
Cluster Intrinsic Alignment in DES Y1
Clusters of galaxies trace the most non-linear peaks in the cosmic density field. The weak gravitational lensing of background galaxies by clusters can allow us to infer their masses. However, galaxies associated with the local environment of the cluster can also be intrinsically aligned due to the local tidal gradient, contaminating any cosmology derived from the lensing signal. In this talk, ...
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