TY - JOUR
T1 - Uncovering the stellar structure of the dusty star-forming galaxy GN20 at z?=?4.055 with MIRI/JWST
AU - Colina, L.
AU - Crespo Gómez, A.
AU - Álvarez-Márquez, J.
AU - Bik, A.
AU - Walter, F.
AU - Boogaard, L.
AU - Labiano, A.
AU - Peissker, F.
AU - Pérez-González, P.
AU - Östlin, G.
AU - Greve, T. R.
AU - Nørgaard-Nielsen, H. U.
AU - Wright, G.
AU - Alonso-Herrero, A.
AU - Azollini, R.
AU - Caputi, K. I.
AU - Dicken, D.
AU - García-Marín, M.
AU - Hjorth, J.
AU - Ilbert, O.
AU - Kendrew, S.
AU - Pye, J. P.
AU - Tikkanen, T.
AU - Van Der Werf, P.
AU - Costantin, L.
AU - Iani, E.
AU - Gillman, S.
AU - Jermann, I.
AU - Langeroodi, D.
AU - Moutard, T.
AU - Rinaldi, P.
AU - Topinka, M.
AU - Van Dishoeck, E. F.
AU - Güdel, M.
AU - Henning, Th
AU - Lagage, P. O.
AU - Ray, T.
AU - Vandenbussche, B.
N1 - Publisher Copyright:
© 2023 - IOS Press. All rights reserved.
PY - 2023
Y1 - 2023
N2 - Luminous infrared galaxies at high redshifts (z > 4) include
extreme starbursts that build their stellar mass over short periods of
time, that is, of 100 Myr or less. These galaxies are considered to be
the progenitors of massive quiescent galaxies at intermediate redshifts (z ∼ 2)
but their stellar structure and buildup is unknown. Here, we present
the first spatially resolved near-infrared (rest-frame 1.1 μm) imaging
of GN20, one of the most luminous dusty star-forming galaxies known to
date, observed at an epoch when the Universe was only 1.5 Gyr old. The
5.6 μm image taken with the JWST Mid-Infrared Instrument (MIRI/JWST)
shows that GN20 is a very luminous galaxy (M1.1 μm, AB = −25.01,
uncorrected for internal extinction), with a stellar structure composed
of a conspicuous central source and an extended envelope. The central
source is an unresolved nucleus that carries 9% of the total flux. The
nucleus is co-aligned with the peak of the cold dust emission, and
offset by 3.9 kpc from the ultraviolet stellar emission. The diffuse
stellar envelope is similar in size (3.6 kpc effective radius) to the
clumpy CO molecular gas distribution. The centroid of the stellar
envelope is offset by 1 kpc from the unresolved nucleus, suggesting GN20
is involved in an interaction or merger event supported by its location
as the brightest galaxy in a proto-cluster. Additional faint stellar
clumps appear to be associated with some of the UV- and CO-clumps. The
stellar size of GN20 is larger by a factor of about 3 to 5 than known
spheroids, disks, and irregulars at z ∼ 4, while its size and low
Sérsic index are similar to those measured in dusty, infrared luminous
galaxies at redshift 2 of the same mass (∼1011 M⊙).
GN20 has all the ingredients necessary for evolving into a massive
spheroidal quiescent galaxy at intermediate redshift: it is a large,
luminous galaxy at z = 4.05 involved in a short and massive
starburst centred in the stellar nucleus and extended over the entire
galaxy, out to radii of 4 kpc, and likely induced by the interaction or
merger with a member of the proto-cluster.
AB - Luminous infrared galaxies at high redshifts (z > 4) include
extreme starbursts that build their stellar mass over short periods of
time, that is, of 100 Myr or less. These galaxies are considered to be
the progenitors of massive quiescent galaxies at intermediate redshifts (z ∼ 2)
but their stellar structure and buildup is unknown. Here, we present
the first spatially resolved near-infrared (rest-frame 1.1 μm) imaging
of GN20, one of the most luminous dusty star-forming galaxies known to
date, observed at an epoch when the Universe was only 1.5 Gyr old. The
5.6 μm image taken with the JWST Mid-Infrared Instrument (MIRI/JWST)
shows that GN20 is a very luminous galaxy (M1.1 μm, AB = −25.01,
uncorrected for internal extinction), with a stellar structure composed
of a conspicuous central source and an extended envelope. The central
source is an unresolved nucleus that carries 9% of the total flux. The
nucleus is co-aligned with the peak of the cold dust emission, and
offset by 3.9 kpc from the ultraviolet stellar emission. The diffuse
stellar envelope is similar in size (3.6 kpc effective radius) to the
clumpy CO molecular gas distribution. The centroid of the stellar
envelope is offset by 1 kpc from the unresolved nucleus, suggesting GN20
is involved in an interaction or merger event supported by its location
as the brightest galaxy in a proto-cluster. Additional faint stellar
clumps appear to be associated with some of the UV- and CO-clumps. The
stellar size of GN20 is larger by a factor of about 3 to 5 than known
spheroids, disks, and irregulars at z ∼ 4, while its size and low
Sérsic index are similar to those measured in dusty, infrared luminous
galaxies at redshift 2 of the same mass (∼1011 M⊙).
GN20 has all the ingredients necessary for evolving into a massive
spheroidal quiescent galaxy at intermediate redshift: it is a large,
luminous galaxy at z = 4.05 involved in a short and massive
starburst centred in the stellar nucleus and extended over the entire
galaxy, out to radii of 4 kpc, and likely induced by the interaction or
merger with a member of the proto-cluster.
KW - Galaxies: high-redshift
KW - Galaxies: individual: GN20
KW - Galaxies: starburst
KW - Infrared: galaxies
U2 - 10.1051/0004-6361/202346535
DO - 10.1051/0004-6361/202346535
M3 - Journal article
AN - SCOPUS:85159767463
SN - 0004-6361
VL - 673
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - L6
ER -