Accelerated Formation of Ultra-Massive Galaxies in the First Billion Years
Abstract
Recent JWST observations have revealed an unexpected abundance of massive galaxy candidates in the early Universe, extending further in redshift and to lower luminosity than what had previously been found by sub-millimeter surveys. These JWST candidates have been interpreted as challenging the CDM cosmology, but, so far, they have mostly relied only on rest-frame ultraviolet data and lacked spectroscopic confirmation of their redshifts. Here we report a systematic study of 36 massive dust-obscured galaxies with spectroscopic redshifts between from the JWST FRESCO survey. We find no tension with the CDM model in our sample. However, three ultra-massive galaxies (log ) require an exceptional fraction of 50% of baryons converted into stars -- two to three times higher than even the most efficient galaxies at later epochs. The contribution from an active nucleus is unlikely because of their extended emission. Ultra-massive galaxies account for as much as 17% of the total cosmic star formation rate density at .
Keywords
Cite
@article{arxiv.2309.02492,
title = {Accelerated Formation of Ultra-Massive Galaxies in the First Billion Years},
author = {Mengyuan Xiao and Pascal Oesch and David Elbaz and Longji Bing and Erica Nelson and Andrea Weibel and Garth Illingworth and Pieter van Dokkum and Rohan Naidu and Emanuele Daddi and Rychard Bouwens and Jorryt Matthee and Stijn Wuyts and John Chisholm and Gabriel Brammer and Mark Dickinson and Benjamin Magnelli and Lucas Leroy and Daniel Schaerer and Thomas Herard-Demanche and Seunghwan Lim and Laia Barrufet and Ryan Endsley and Yoshinobu Fudamoto and Carlos Gómez-Guijarro and Rashmi Gottumukkala and Ivo Labbe and Daniel Magee and Danilo Marchesini and Michael Maseda and Yuxiang Qin and Naveen Reddy and Alice Shapley and Irene Shivaei and Marko Shuntov and Mauro Stefanon and Katherine Whitaker and J. Stuart Wyithe},
journal= {arXiv preprint arXiv:2309.02492},
year = {2024}
}
Comments
Nature in press. Updated to the accepted version. 24 pages, 4 main figures, 7 supplementary figures, 3 supplementary tables