Title：The role of radiation and supernova feedback on Lyman continuum escape from star-forming galaxies

Speaker：Cody Carr (Zhejiang University)

Time: 10:00 am Apr.30 (Wednesday)

Location: 3rd floor Middle Conference Room.

Abstract：

 The Low-z Lyman Continuum Survey (LzLCS) is the largest systematic investigation to date of Lyman continuum (LyC) escape fractions (fesc) in local star-forming galaxies, increasing the total number of confirmed LyC leakers to approximately 35 at redshift ~ 0.3. One of the key conclusions of the survey is that no single diagnostic—such as the [O III]/[O II] ratio—can reliably predict fesc across a diverse galaxy population. This highlights the complex physical processes that govern the journey of LyC photons, from their production in massive stars to their escape through the surrounding interstellar and circumgalactic media (ISM/CGM).  In this talk, I will present new results that explore how stellar feedback regulates LyC escape in the LzLCS sample. By applying radiative transfer modeling to the Mg II 2800 Å doublet, we trace the properties of cool outflows and examine how they shape the CGM. Using stellar population synthesis models, we estimate the ages of the dominant stellar populations and identify the primary feedback mechanism—radiative or mechanical (e.g., supernova-driven)—in each system.  I will conclude by proposing a feedback-based timeline for LyC escape that reconciles the observed diversity in fesc, with implications for understanding reionization-era galaxies at high redshift.


CV:

Dr. Cody Carr is a postdoctoral researcher at Zhejiang University in Hangzhou, China, where he works with Professor Renyue Cen. He earned his Ph.D. in astronomy from the University of Minnesota in 2023 under the guidance of Professor Claudia Scarlata. His research centers on galaxy formation, with a particular emphasis on radiative transfer theory. He is the lead developer of the SALT model, a tool designed to predict the spectral signatures of galactic outflows and inflows. In 2024, he was awarded both the Talent Introduction Program Fund and the Research Fund for International Scientists, supported by the National Science Foundation of China (NSFC).