A core in a star-forming disc as evidence of inside-out growth in the early Universe
View/
Author
Baker, William M.
Tacchella, Sandro
Johnson, Benjamin D.
Nelson, Erica
Suess, Katherine A.
D’Eugenio, Francesco
Curti, Mirko
de Graaff, Anna
Ji, Zhiyuan
Maiolino, Roberto
Robertson, Brant
Scholtz, Jan
Alberts, Stacey
Arribas, Santiago
Boyett, Kristan
Bunker, Andrew J.
Carniani, Stefano
Charlot, Stephane
Chen, Zuyi
Chevallard, Jacopo
Curtis-Lake, Emma
Danhaive, A. Lola
DeCoursey, Christa
Egami, Eiichi
Eisenstein, Daniel J.
Endsley, Ryan
Hausen, Ryan
Helton, Jakob M.
Kumari, Nimisha
Looser, Tobias J.
Maseda, Michael V.
Puskás, Dávid
Rieke, Marcia
Sandles, Lester
Sun, Fengwu
Übler, Hannah
Williams, Christina C.
Willmer, Christopher N. A.
Witstok, Joris
Attention
2299/28520
Abstract
The physical processes that establish the morphological evolution and the structural diversity of galaxies are key unknowns in extragalactic astrophysics. Here we report the finding of the morphologically mature galaxy JADES-GS+53.18343−27.79097, which existed within the first 700 million years of the Universe’s history. This star-forming galaxy with a stellar mass of 400 million solar masses consists of three components: a highly compact core with a half-light radius of less than 100 pc, an actively star-forming disc with a radius of about 400 pc and a star-forming clump, all of which show distinctive star-formation histories. The central stellar mass density of this galaxy is within a factor of 2 of the most massive present-day ellipticals, while being globally 1,000 times less massive. The radial profile of the specific star-formation rate is rising towards the outskirts. This evidence suggests a detection of the inside-out growth of a galaxy as a proto-bulge and a star-forming disc in the epoch of reionization.