TY - JOUR
T1 - Massive galaxy formation caught in action at z ∼ 5 with JWST
AU - Jin, Shuowen
AU - Sillassen, Nikolaj B.
AU - Magdis, Georgios E.
AU - Vijayan, Aswin P.
AU - Brammer, Gabriel B.
AU - Kokorev, Vasily
AU - Weaver, John R.
AU - Gobat, Raphael
AU - Giménez-Arteaga, Clara
AU - Valentino, Francesco
AU - Brinch, Malte
AU - Gómez-Guijarro, Carlos
AU - Shuntov, Marko
AU - Toft, Sune
AU - Greve, Thomas R.
AU - Blanquez Sese, David
N1 - Publisher Copyright:
© The Authors 2023.
PY - 2023
Y1 - 2023
N2 - We report the discovery of a compact group of galaxies, CGG-z5, at z ∼ 5.2 in the EGS field covered by the JWST/CEERS survey. CGG-z5 was selected as the highest overdensity of galaxies at z >
2 in recent JWST public surveys and it consists of six candidate
members lying within a projected area of 1.5″ × 3″ (10×20 kpc2).
All group members are HST/F435W and HST/F606W dropouts while securely
detected in the JWST/NIRCam bands, yielding a narrow range of robust
photometric redshifts 5.0 < z < 5.3. The most massive galaxy in the group has a stellar mass log(M*/M⊙)≈9.8, while the rest are low-mass satellites (log(M*/M⊙)≈8.4–9.2).
While several group members were already detected in the HST and IRAC
bands, the low stellar masses and the compactness of the structure
required the sensitivity and resolution of JWST for its identification.
To assess the nature and evolutionary path of CGG-z5, we searched for
similar compact structures in the EAGLE simulations and followed their evolution with time. We find that all the identified structures merge into a single galaxy by z = 3 and form a massive galaxy (log(M*/M⊙)> 11) at z ∼ 1.
This implies that CGG-z5 could be a “proto-massive galaxy” captured
during a short-lived phase of massive galaxy formation.
AB - We report the discovery of a compact group of galaxies, CGG-z5, at z ∼ 5.2 in the EGS field covered by the JWST/CEERS survey. CGG-z5 was selected as the highest overdensity of galaxies at z >
2 in recent JWST public surveys and it consists of six candidate
members lying within a projected area of 1.5″ × 3″ (10×20 kpc2).
All group members are HST/F435W and HST/F606W dropouts while securely
detected in the JWST/NIRCam bands, yielding a narrow range of robust
photometric redshifts 5.0 < z < 5.3. The most massive galaxy in the group has a stellar mass log(M*/M⊙)≈9.8, while the rest are low-mass satellites (log(M*/M⊙)≈8.4–9.2).
While several group members were already detected in the HST and IRAC
bands, the low stellar masses and the compactness of the structure
required the sensitivity and resolution of JWST for its identification.
To assess the nature and evolutionary path of CGG-z5, we searched for
similar compact structures in the EAGLE simulations and followed their evolution with time. We find that all the identified structures merge into a single galaxy by z = 3 and form a massive galaxy (log(M*/M⊙)> 11) at z ∼ 1.
This implies that CGG-z5 could be a “proto-massive galaxy” captured
during a short-lived phase of massive galaxy formation.
KW - Galaxies: groups: individual: CGG-z5
KW - Galaxies: high-redshift
KW - Galaxy: evolution
KW - Galaxy: formation
KW - Infrared: galaxies
U2 - 10.1051/0004-6361/202245724
DO - 10.1051/0004-6361/202245724
M3 - Journal article
AN - SCOPUS:85147649983
SN - 0004-6361
VL - 670
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - L11
ER -