1 research outputs found
Early Results from GLASS-JWST. XXI: Rapid assembly of a galaxy at z=6.23 revealed by its C/O abundance
The abundance of carbon relative to oxygen (C/O) is a promising probe of star
formation history in the early universe, as the ratio changes with time due to
production of these elements by different nucleosynthesis pathways. We present
a measurement of (stat) (sys)
in a galaxy observed as part of the GLASS-JWST Early Release Science
Program. Notably, we achieve good precision thanks to the detection of the
rest-frame ultraviolet O III], C III], and C IV emission lines delivered by
JWST/NIRSpec. The C/O abundance is 0.8 dex lower than the solar value and
is consistent with the expected yield from core-collapse supernovae, indicating
that longer-lived intermediate mass stars have not fully contributed to carbon
enrichment. This in turn implies rapid buildup of a young stellar population
with age Myr in a galaxy seen 900 million years after the
Big Bang. Our chemical abundance analysis is consistent with spectral energy
distribution modeling of JWST/NIRCam photometric data, which indicates a
current stellar mass and specific star formation rate sSFR
Gyr. These results showcase the value of chemical abundances and C/O in
particular to study the earliest stages of galaxy assembly.Comment: 16 pages, 4 figures, 2 tables. Accepted for publication in ApJ