Miguel F. Morales' Research

I am an observational cosmologist, and I lead the Radio Cosmology group at the University of Washington. I've also written a popular seven article series on Quantum Mechanics for arstechnica.com—more than 60,000 people have read the full series. These articles use no math and are accessible to broad audience, and if you'd like to use them in a class an accompanying teaching guide can be found here. I am also passionate about diversity and access in physics, and a more personal page about my background can be found here.

Epoch of Reionization Observations

The history of our Universe is written in hydrogen. After the Big Bang and the making of the elements, the universe was filled with a smooth hydrogen-helium plasma with conditions very similar to the outer parts of our Sun. As the universe cooled the hydrogen suddenly changed from an ionized plasma to a neutral gas—just like when water vapor condenses into a cloud. If you look far enough in any direction (and have the right observational tools) you see a wall of glowing plasma called the cosmic microwave background (CMB) that is a result of this phase transition in hydrogen.

After the hydrogen becomes neutral, gravity starts to inexorably pull the gas together, eventually creating the first stars and galaxies a little less than a billion years after the Big Bang. These primordial stars and galaxies emit ultraviolet light that reionizes the hydrogen. This burning off of the neutral hydrogen fog by the first stars and galaxies is called the Epoch of Reionization (EoR). Marcelo Alvarez has one of my favorite movies of the reionization process.

Observing the formation of the first stars and galaxies is scientifically compelling, but also very difficult.

My colleagues and I design and build state-of-the-art radio telescopes and the precision data analysis techniques needed to observe the Universe's first stars as they formed and ionized hydrogen 13 billion years ago. We have helped to build both the Murchison Widefield Array located in the Western Australian desert (MWA) and the Hydrogen Epoch of Reionization Array (HERA) in the Karoo desert of South Africa.

I currently help lead an international effort to analyze more than 9 PetaBytes of data from the MWA, and I'm the imaging power spectrum lead for HERA. Recent work includes some of the deepest limits to date Barry et al. 2019 & Li et al. 2019; advances in calibration Byrne et al. 2020 & 2019; mitigation of ultra-faint RFI Wilensky et al. 2020 & 2019; understanding the diversity of 21 cm cosmology analyses Morales et al. 2019; and a precise polarized map of the diffuse galactic emission across the southern cap (Byrne et al. 2021).

If you would like more information about our work, an invited review article on 21 cm Epoch of Reionization and dark energy observations can be found here, and an automated listing of our recent papers here. Please feel free to contact me about my research and opportunities in cosmology at the University of Washington.

-Miguel F. Morales