Miguel F. Morales' Research

My research focus is observational cosmology, and I lead the Radio Cosmology group at the University of Washington. Our particular expertise is state-of-the art data analysis and the design and construction of next generation radio interferometers. We are best known for 21 cm observations of the Epoch of Reionization, and we have projects measuring the expansion history of the universe (dark energy), searching for axions, and developing new cosmology signatures. 

The UW RadCos group currently includes postdocs Bryna Hazelton, Ian Sullivan, and Jonathan Pober; graduate students Adam Beardsley (physics) and Patricia Carroll (astronomy); and undergraduates Jessica Murray, Zac Martinot, Zac Banks, Nancy Sackman, and Orlala Wentink. Most of our present effort is analyzing deep Epoch of Reionization data from the Murchison Widefield Array (MWA; Facebook) and PAPER instruments, commissioning the GASE experiment, designing the Hydrogen Epoch of Reionization Array (HERA), and developing the MOFF correlator. 

Epoch of Reionization Observations

Many of the milestone events in the history of the universe are written in the phases of hydrogen. After the Big Bang and nucleosynthesis (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, this hydrogen suddenly changed from a plasma into a neutral gas. This ‘phase change’ is analogous to water vapor condensing 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. 

The next major milestone in the history of the universe is the lighting up of the first stars and galaxies a little less than a billion years after the release of the CMB. These primordial stars and galaxies emitted ultraviolet light that reionized the hydrogen, melting the gas back into a plasma. 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 build and use special purpose radio telescopes such as the MWA, PAPER and HERA that are tuned to detect the faint 21 cm radio line emitted by neutral hydrogen. Observing the 21 cm EoR signal was rated the top priority in radio astronomy by the Astro2010 decadal survey.

The UW RadCos group plays a leading role in the analysis of MWA and PAPER data, and has pushed the frontier of precision data analysis and foreground subtraction. This work includes the development of Fast Holographic Deconvolution, understanding of mode-mixing and the origin of the EoR Window, and developing a direct imaging power spectrum pipeline. 

Other cosmology observations

The RadCos group is also involved in a number of other cosmology projects. The undergraduate and community college students are commissioning the GASE (pronounced ‘gaze’) instrument on the roof of Sieg Hall (group photos in above slideshow). GASE is one of the only teaching interferometers in the country. If there are 30 MHz radio bursts in association with Gamma Ray Bursts, GASE would pioneer a new way of measuring dark energy. In addition we are looking for axions using MWA observations and ADMX (dark matter), understanding instrumental systematics with LSST weak lensing observations (dark energy), and developing velocity resolved weak lensing measurements (dark energy & dark matter) and high speed digital hardware for next generation radio instruments (MOFF correlator).

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

P.S. A long time ago, I developed movies of extensive air showers that became popular in the astroparticle community. If you are looking for them, please visit the Milagro Animations web site.