1 research outputs found
RIOJA I. The core of the highest redshift galaxy overdensity at confirmed by NIRSpec/JWST
The proto-clusters in the epoch of reionization, traced by galaxies
overdensity regions, are ideal laboratories to study the process of stellar
assembly and cosmic reionization. We present the spectroscopic confirmation of
the core of the most distant proto-cluster at , A2744-z7p9OD, with
the James Webb Space Telescope NIRSpec integral field unit spectroscopy. The
core region includes as many as 4 galaxies detected in [O III] 4960 A and 5008
A in a small area of , corresponding to 11 kpc
11 kpc. Three member galaxies are also tentatively detected in dust
continuum in ALMA Band 6, which is consistent with their red ultraviolet
continuum slopes, . The member galaxies have stellar masses in
the range of log() and star formation rates
of yr, showing a diversity in their
properties. FirstLight cosmological simulations reproduce the physical
properties of the member galaxies including the stellar mass, [OIII]
luminosity, and dust-to-stellar mass ratio, and predict that the member
galaxies are on the verge of merging in a few to several tens Myr to become a
large galaxy with . The presence of
a multiple merger and evolved galaxies in the core region of A2744-z7p9OD
indicates that environmental effects are already at work 650 Myr after the Big
Bang.Comment: 10 pages, 4 figures, 1 table, submitted to ApJ