MATs (Monday Afternoon Talks), 04/24/2023 – Speakers: Xiurui Zhao (CfA) & Sebastian Von Hausegger (Oxford)

Monday April 24, 2023 3:00 pm

MATs (Monday Afternoon Talks)

3:00pm  – Xiurui, CfA

Active Galactic Nuclei in the NuSTAR Era
Active galactic nuclei (AGN), which represent the rapidly growing phase of the supermassive black holes (SMBH), radiate across the whole electromagnetic spectrum from radio to Gamma-rays. X-rays, which are seen in most AGN, are an important tool to study the physics of AGN. Thanks to the launch of NuSTAR in 2012, we are able to probe AGN properties in the hard X-ray regime for the first time. In this presentation, I will introduce our recent progress on different aspects of AGN, including the properties of the AGN dusty tori, X-ray emitting corona and AGN demographics.


3:30pm  – Sebastian von Hausegger 

The cosmic matter dipole
The ever-growing quantity and quality of astronomical data today has underpinned both the LCDM model of cosmology and general relativity as effective working theories.  Yet also tensions between theoretical prediction and observation, and even between different observations arose.  I will centre my presentation on one such discrepancy — the excess amplitude of the cosmic matter dipole in the number density of high-redshift galaxies.  This observation represents a significant challenge to the Cosmological Principle, upon which the LCDM model is built, evocative of inhomogeneous and anisotropic cosmological models.  I will present details of this analysis, and also provide an overview of the relevant literature and elaborate on consequences as well as future research directions.

Host: Josh Borrow


  • Xiurui Zhao, CfA
  • Sebastian von Hausegger, Oxford

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