SPURS: Insights into UV-luminous galaxies at z>9 from deep R~1000 spectroscopy

Thursday 15 Oct 2026, 14:00 → 15:00 Asia/Shanghai

Tsung-Dao Lee Institute/S4F-SW - Open Area (Tsung-Dao Lee Institute)

Zuyi Chen（陈祖诒）

Title: SPURS: Insights into UV-luminous galaxies at z>9 from deep R~1000 spectroscopy
Time: 14:00-15:00 (UTC+8), 15 October 2026, Thursday 
Host: Mengtao Tang
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Abstract：
JWST observations have provided an unprecedented view of cosmic dawn, revealing a high number density of UV-luminous galaxies, a shift to more extreme emission lines, and peculiar, globular-cluster-like nitrogen abundances. However, characterizing the stellar and ISM properties of individual galaxies at this epoch has remained challenging due to the low resolution and/or shallow depth of previous spectra, limiting our ability to interpret these discoveries. I will present results from SPURS, a 200 hr Cycle 4 Large NIRSpec program that obtained the first extremely deep (29 hr) medium-resolution (R~1000) rest-UV spectra of early galaxies. I will show new constraints on galaxy-scale outflows and stellar winds in two UV-luminous galaxies, SPURS-A2744-7 at z=9.3 and GN-z11 at z=10.6. In GN-z11, we detect rich stellar and gas features, including P-Cygni wind profiles, broad He II, N IV] and Lya emission, fluorescent O I* emission, and weak low-ionization absorption. I will discuss how these features may be providing our first view of a low-metallicity very massive star (VMS, >100 Msun) population at z>10, potentially building the dense nuclear region and the surrounding clusters in a burst of star formation. These spectra offer new insights into bursty star formation at such early epochs, with implications for nitrogen enrichment and the seeding of intermediate-mass black holes.

Biography:
Zuyi Chen (陈祖诒) is a postdoctoral researcher at the Cosmic Dawn Center (DAWN) / Niels Bohr Institute, University of Copenhagen. His research focuses on observational constraints on early galaxy formation and how best to use these galaxies as probes of cosmic reionization. He received his B.S. from the University of Science and Technology of China in 2019 and Ph.D. from the University of Arizona in 2025.