Past Event

New Probes of Astrophysics and Cosmology with Line-Intensity Mapping

April 26, 2023
4:05 PM - 5:05 PM
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Pupin 1402

Colloquium by Adrian Liu, McGill

Line-Intensity Mapping (LIM) is a technique that is poised to dramatically increase the reach of cosmological surveys. With LIM, one creates a map of the sky by averaging the total line emission over coarse pixels rather than by resolving individual astrophysical objects. This enables highly efficient 3D surveys of our Universe that cover unprecedentedly large volumes and open up new portions of our cosmic timeline to observations. In this talk, I will highlight several recent results in LIM as well as some future opportunities for the technique. I will begin with an overview of 21cm LIM at high redshifts and explain recent results from the Hydrogen Epoch of Reionization Array (HERA). HERA is a low-frequency radio interferometer in the South African Karoo Desert that is designed to target Cosmic Dawn and Reionization, when first-generation stars and galaxies were born. Our results represent some of the first 21cm constraints on the era and suggest that today's galaxies are likely different in nature than their ancestors. Looking to the future, I will show how machine learning can be used to extract additional information from 21cm observations amidst contaminating influences. I will also highlight ways in which LIM of different lines can complement each other as well as Cosmic Microwave Background experiments, potentially enabling model-independent constraints on our Universe's ionization history in addition to precision constraints on cosmology at z~5.

Followed by wine and cheese.

Host: Zoltan Haiman