Evolution and Impact of Stellar Bars out to z ~4 with JWST

Tuesday 3 Feb 2026, 21:20 → 21:40 Asia/Shanghai

Tsung-Dao Lee Institute

Speaker: Yuchen Guo（University of Texas）
Time:  21:20-21:40 (UTC+8), 3 February 2026, Tuesday
Host: Dong Lai
Location: Online
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Meeting ID: 777306620 (no password）

Abstract:

Studying barred galaxies at early cosmic epochs provides key insights into the formation of stellar bars and their role in driving the secular evolution of galaxies, as well as into the evolutionary pathways of our own Milky Way. Over the past two decades, studies based on Hubble Space Telescope data have primarily probed barred galaxies out to z ∼1.5.  The advent of the James Webb Space Telescope (JWST) is now transforming this field.  Using JWST CEERS data, we present the first exploration of barred galaxies in the young Universe out to z∼4, when the Universe was only ~11% of its current age (Guo+2023, Guo+2025). Our results reveal the early emergence of stellar bars at z∼3-4, and highlight the increasing importance of bar-driven secular evolution from z∼4 to the present day. To further investigate barred galaxies at z>1, we perform spatially resolved SED-fitting analysis on selected barred galaxies at z ~1-2 (Guo+2026, in prep.), examining the spatial distribution and variations of physical properties such as stellar mass, star formation rates, stellar populations, and dust. Together, these studies address some of the key big-picture questions about stellar bars in the JWST era.

Biography:

Yuchen Guo is a PhD candidate in Astronomy at the University of Texas at Austin, working with Prof. Shardha Jogee. Yuchen's research focuses on galaxy evolution over the past 12 billion years, particularly the role of stellar bars in driving secular evolution. Using JWST and HST observations, she led one of the first explorations of the emergence, evolution, and impact of stellar bars out to z~4.