Packard Fellowship Will Help Cosmologist Probe What the Universe is Made Of

Woman at night in front of telescope

Elisabeth Krause at the Cerro Tololo Inter-American Observatory in Chile in front of the Víctor M. Blanco Telescope as it collects Dark Energy Survey data.

Elisabeth Krause

Elisabeth Krause

Elisabeth Krause

University of Arizona assistant professor Elisabeth Krause has received a highly competitive and prestigious fellowship from the David and Lucile Packard Foundation that will help her tackle some of the biggest questions in modern science.

Krause, who has joint appointments in the Department of Astronomy and Department of Physics, is one of 20 early-career scientists and engineers selected for this year's Packard Fellowships for Science and Engineering, an honor that comes with $875,000 awarded over five years. The award will allow Krause to expand her work studying the structure of the universe on the largest scales.

"I'm a cosmologist," she says, "I want to figure out what the universe is made of."

Krause's work bridges the space between astronomical observations and theory. As telescopes and their instruments become ever-more sophisticated and produce a deluge of data, it becomes increasingly difficult, if not impossible, for any particular research team to make sense of it all, Krause said. An important piece of her work is dedicated to developing algorithms for observations, which she describes as the glue that is needed to connect data to theory.

"We have different ways of probing different aspects of the universe, and my research aims at figuring out how to put all those pieces together. It's very similar to one big puzzle," she said.

Currently, Krause's focus is on data from the Dark Energy Survey, or DES, aimed at measuring properties of dark energy – a mysterious force that cosmologists have inferred from the fact that the universe has been expanding faster and faster over time, but that nobody has ever been able to observe.

As science co-chair of the international DES collaboration, she is in the process of finishing the analysis of data taken with the National Science Foundation's Victor M. Blanco Telescope in Chile, which measured the shape and position of more than 100 million galaxies to generate a map that will reveal structures in the cosmos that are extremely difficult to tease out from observational data. 

"On very large scales, we can use basic physics to relate the distribution of dark matter to galaxies," Krause said, "but once you zoom in, math alone no longer works."

One method Krause uses to uncover structures on smaller scales – which to most people who aren't cosmologists still are unimaginably large – is analyzing observations of individual galaxies and studying how they cluster together.

"By analyzing galaxy clustering, we want to relate the distribution of light from those galaxies to the distribution of matter – most importantly, dark matter," Krause said. "You can think of it a little bit like looking at satellite images of Earth by night: You can see the distribution of cities and continents, and from that you can infer things like, 'Oh, there must be land, and over there must be ocean.'"

Krause has excelled at helping to create and manage the large multinational collaborations required to pursue her scientific aspirations. As part of the Dark Energy Survey, she works closely with a team of about 70 scientists. She also advises two doctoral students at UArizona. She says the fellowship will allow her to work beyond individual collaborations, which often are funded by partner agencies for a particular instrument.

"The Packard Fellowship will allow me to work across those boundaries and put together the much bigger puzzle," she said. "Now I can synthesize observations in many different wavelengths, made with different telescopes and instruments, and put all those together in one coherent analysis."

The Packard Fellowships in Science and Engineering are among the nation’s largest nongovernmental fellowships, designed to allow maximum flexibility in how the funding is used. Since 1988, the program has supported the blue-sky thinking of scientists and engineers whose research over time has led to new discoveries that improve people’s lives and enhance understanding of the universe. Packard Fellows are at the cutting edge of research on crucial issues like COVID-19 and climate change, and have gone on to receive the highest accolades, including Nobel Prizes in chemistry and physics, the Fields Medal, the Alan T. Waterman Award, the Breakthrough Prize, the Kavli Prize, and elections to the National Academies of Science, Engineering and Medicine. Notably, all three U.S. women who won the Nobel Prize in the past three years are Packard Fellows: Frances Arnold, Jennifer Doudna and Andrea Ghez.

The program was inspired by David Packard's commitment to strengthen university-based science and engineering programs in the United States. He recognized that the success of the Hewlett-Packard Company, which he co-founded, was derived in large measure from research and development in university laboratories. Since 1988, the foundation has awarded $447 million to support scientists and engineers from 54 national universities.

Krause says she chose UArizona to pursue her work because of its unique combination of a highly diverse landscape of world-class facilities and experts in astronomy, physics, optics and engineering.

"To understand cosmology, I need to understand what is going on with galaxies and pixels, and Steward Observatory is a fantastic environment that brings together so many people from astronomy with whom I can talk about the subtleties of observing, but also engineers on the instrumentation side," she said. "And, in the end, you also want to be able to do hardcore physics, like at the Large Hadron Collider at CERN, but through galaxies, and there is a lot of astrophysics in between."

Krause says she is particular excited about the Vera C. Rubin Observatory coming online around 2022. It was previously known as the Large Synoptic Survey Telescope and is run by the National Science Foundation and the U.S. Department of Energy. With its huge wide-field camera, the telescope will be the first to continuously scan the night sky over vast stretches of the universe, generating a "movie of the cosmos." All data will be made available to the public as it is generated. The telescope's unique primary and tertiary mirrors were manufactured at the Richard F. Caris Mirror Lab, which is part of Steward Observatory.

"The statistical power of all these experiments will be mind-blowing," Krause said. "We will have these very, very precise measurements, but that means we also will have very accurate analysis that requires astrophysics in addition to cosmology."

"Astrophysics and cosmology used to be their own subfields," she added, "but to get the best out of the Vera C. Rubin Observatory and other surveys, we have to synthesize knowledge across scientific communities, develop a common language and stand on equal footing. The fellowship will allow me to bring experts to the University of Arizona, and it will give me and my students the freedom to think beyond survey boundaries."

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