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Frontiers Of Science 2024

Exploring Scientific
Progress Over Time

“Surprises at the Dawn of Time from James Webb: A First Look at the First Stars, Galaxies, and Black Holes”

Presented by Joel Leja
Assistant professor of astronomy and astrophysics and Institute for Computational and Data Sciences Faculty Fellow at Penn State

February 3, 2024
100 Huck Life Sciences Building (Berg Auditorium)
11:00 a.m. to 12:30 p.m.


Joel Leja.

The James Webb Space Telescope is the culmination of thirty years of planning, twenty years of construction, and eleven billion dollars of funding. It is the most expensive and complex astronomical observatory ever built and it was designed specifically to perform the first systematic exploration of stars, galaxies, and black holes in the early universe. Luckily for us, this first systematic exploration is happening right now --- in our lives. Leja will provide an overview of this flagship telescope and discuss some of the stunning early, and sometimes tentative, discoveries that have been made in Webb's first deep fields from the first light of galaxies and black holes, which has travelled many billions of years through empty space before being captured by Webb.

Joel Leja, assistant professor of astronomy and astrophysics and Institute for Computational and Data Sciences Faculty Fellow at Penn State tries to understand how galaxies form using big telescopes, large surveys, and fast computers. He specializes in modeling observations of distant galaxies and in astrophysical computing. Recently, Leja has been analyzing the first very deep surveys with the James Webb Space Telescope, discovering and characterizing galaxies formed in the first few billion years of the Universe. Joel has authored or coauthored over a hundred scientific papers in journals such as The Astrophysical Journal, Monthly Notices of the Royal Astronomical Society, and Nature, and named a Clarivate Highly Cited Researcher in 2023 (top 1% of cited researchers in astrophysics). He was awarded the Yale University's Brouwer Prize in 2019 for a Ph.D thesis of unusual merit. Prior to joining the faculty at Penn State, Joel was a postdoctoral researcher at the Center for Astrophysics | Harvard & Smithsonian. He earned a doctoral degree in astronomy at Yale University in 2016 and a bachelor’s degree in physics and astrophysics at the University of California, Berkeley, in 2010.

Michael Eracleous.

In 2009, the theme of the lecture series was “Our Universe: From the Big Bang to Life.” That year, Professor of Astronomy and Astrophysics Michael Eracleous presented a lecture titled “Galaxies and their supermassive blackholes." 

Eracleous will present a brief update on the research topic and an introduction before Leja's lecture.

The main theme underlying his research is accretion power, how the accumulation of particles through the gravitational pull of massive objects can be a source of energy in active galactic nuclei, but he works on a wide variety of topics spanning binary stars, quasars, galaxy evolution, and the astrophysics of gravitational wave sources. He earned a doctoral degree in physics from Columbia University in 1992 and has been a member of the faculty in the Department of Astronomy and Astrophysics at Penn State since 1998.