Northwestern astrophysicists snag early time on James Webb Space Telescope

• Link to: Northwestern Now Story

After releasing its first full-color images from the James Webb Space Telescope (JWST) this morning, NASA officially has transitioned its new telescope to scientific operations. Two Northwestern University astrophysicists have gained coveted early access to the telescope, beginning observations this summer.

Starting within the next month, Northwestern’s Allison Strom will lead the CECILIA (Chemical Evolution Constrained using Ionized Lines in Interstellar Aurorae) Survey, which will study the chemistry of distant galaxies.

From Aug. 5 through Sept. 25, 2022, Northwestern’s Farhad Yusef-Zadeh will contribute to a team studying star formation at the heart of the Milky Way galaxy. This project is led by Nadeen Sabha at the University of Innsbruck in Austria. Next year, Yusef-Zadeh also will lead a project using JWST to examine Sagittarius A*, our galaxy’s central supermassive black hole.

About CECILIA

Named after Cecilia Payne-Gaposchkin, one of the first women to earn a Ph.D. in astronomy, the CECILIA Survey will observe the spectra (or amount of light across different wavelengths) from distant galaxies in order to decipher the galaxies’ chemical compositions. With these observations, Strom and the CECILIA team aim to determine the amount of key elements, such as oxygen and sulfur, present in young galaxies that formed more than 10 billion years ago. The abundance of these elements will give insight into the formation of stars, which is crucial for understanding how galaxies — including our own Milky Way — form and evolve.

“One of the principal goals of modern astronomy — and one of the main scientific drivers for JWST — is to understand how galaxies formed and evolved in the early universe,” Strom said. “A key piece of evidence is what those galaxies are made of. With CECILIA, we have a chance to directly measure the chemistry of distant galaxies, using an incredibly powerful method that is only possible with JWST. CECILIA will be the cipher, similar to the Rosetta Stone, that enables astronomers to crack the code and accurately interpret the thousands of other spectra of distant galaxies that JWST will observe throughout its lifetime.” 

Strom joined Northwestern on July 1, 2022, as an assistant professor of physics and astronomy in the Weinberg College of Arts and Sciences and a key member of Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA).

Previously, Strom was a Carnegie-Princeton Postdoctoral Fellow at Princeton University. One of her primary goals is to understand what causes galaxies to end up the way they are today — a longstanding open question in the astronomy field. Throughout her career, Strom has used some of the world’s largest telescopes to address this question, leveraging their enormous technological power to observe “adolescent” galaxies in the very distant universe.

About star formation in the inner Milky Way

Yusef-Zadeh is a member of a European collaboration that will use the JWST to examine faint mid-infrared sources located just half a parsec away from Sagittarius A*. Even though these sources are dangerously close to the supermassive black hole, astrophysicists believe they potentially could be low-mass stars. If the team is able to confirm that the sources are stars, that would imply that planets, too, could form in stressed environments near galaxies’ central supermassive black holes.

Yusef-Zadeh is a professor of physics and astronomy in the Weinberg College and member of CIERA. In Spring 2023, he will lead a group to study flares from Sagittarius A* to better understand how flares behave and the mechanisms behind them. A radio astronomer, Yusef-Zadeh has spent nearly 40 years studying the Milky Way’s center. His work has led to several ground-breaking discoveries, including the mysterious filaments and giant bubbles at the center of our galaxy.