Astroseminar - Jennifer Chan - IN PERSON | Waterloo Centre for Astrophysics

Jennifer Chan is a postdoctoral fellow at the Canadian Institute for Theoretical Astrophysics (CITA) and the Dunlap Institute for Astronomy & Astrophysics at the University of Toronto, supported by joint CITA and University of Toronto Faculty of Arts & Science fellowships. She earned her Ph.D. and M.Sc. in Astrophysics from University College London, and a Bachelor's in Physics from the University of Oxford. Her research focuses on investigating the origins, evolution, and properties of large-scale magnetic fields in the Universe, essential for understanding their impact on cosmic structures. She also studies cosmological reionization, the transition of the Universe from a neutral state to a highly ionized intergalactic medium, which shaped the vast cosmic web connecting galaxies. To advance these studies, she develops tools that bridge theory and observation in the fields of cosmic magnetism and reionization, such as covariant cosmological radiative transfer formalisms, which accurately model the propagation of electromagnetic radiation through different astrophysical environments in an expanding, evolving Universe.

Title: Charting the Evolving Universe: Insights into Cosmic Reionization and Magnetism through Cosmological Radiative Transfer

Abstract: Astrophysics is entering a new era, with cutting-edge research methods allowing us to explore the vast scales of cosmic reionisation and magnetic fields in unprecedented detail. This seminar will examine cutting-edge progress on these topics, presenting a covariant cosmological radiative transfer (CRT) framework that effectively bridges theoretical predictions and observational insights.

Specifically, through the CRT of the 21-cm line of neutral hydrogen, we can accurately track key epochs, from the Dark Ages to the Epoch of Reionisation — central focuses of observational projects like HERA and SKA. I will discuss recent findings (Chan et al. 2024; Wu, Han, Chan 2024) that reveal about 5-10% errors in signal predictions within redshift range 5.5 < z < 35, even in simple scenarios with smoothly-varying reionization histories, challenging standard optical-depth parameterizations and enhancing our interpretive capabilities. Additionally, I will discuss how CRT applied to polarised continuum radiation, combined with cosmological MHD simulations, allows for the generation of detailed polarisation maps—crucial for intercepting observations from GBT, LOFAR, ASKAP, and SKA.

This seminar will conclude by demonstrating CRT's unique capacity to connect simulation and observational data, providing a transformative approach for understanding cosmic reionisation and magnetic fields in the evolving Universe.

Astroseminar - Jennifer Chan - IN PERSON

Join Us!