Probing Infrared eXcess to Investigate Early-Universe Dust (PIXIEDust)
Authors
Tom J. L. C. Bakx
Hiddo S. B. Algera
Jean-Baptiste Jolly
Clarke Esmerian
Kirsten Knudsen
Laura Sommovigo
Joris Witstok
Stefano Carniani
Jianhang Chen
Stephen Eales
Andrea Ferrara
Yoshinobu Fudamoto
Masato Hagimoto
Takuya Hashimoto
Hanae Inami
Akio K. Inoue
Theo Khouri
Ikki Mitsuhashi
Gunnar Nyman
Gustav Olander
Stephen Serjeant
Renske Smit
Ilsang Yoon
Jorge Zavala
Susanne Aalto
Caitlin M. Casey
Yoichi Tamura
Wouter Vlemmings
Abstract
Despite the implied presence of dust through reddened UV emission in high-redshift galaxies, no dust emission has been detected in the (sub)millimetre regime beyond $z > 8.3$. This study combines around two hundred hours of Atacama Large Millimeter/submillimeter Array (ALMA) and Northern Extended Millimeter Array (NOEMA) observations on ten $z > 8$ galaxies, revealing no significant dust emission down to a $1 σ$ depth of $2.0$, $2.0$, and $1.5 \,μ$Jy at rest-frame 158, 88 $μ$m, and across all the data, respectively. This constrains average dust masses to be below $< 10^{5}$ M$_{\odot}$ at $3 σ$ and dust-to-stellar mass ratios to be below $3.7 \times{} 10^{-4}$ (assuming $T_{\rm dust} = 50$ K and $β_{\rm dust} = 2.0$). Binning by redshift ($8 < z < 9.5$ and $9.5 < z < 15$), UV-continuum slope ($β_{\rm UV} \lessgtr -2$) and stellar mass ($\log_{10} M_{\ast}/{\rm M_{\odot}} \lessgtr 9$) yields similarly stringent constraints. Combined with other studies, these results are consistent with inefficient dust build-up in the $z > 8$ Universe, likely due to inefficient supernova production, limited interstellar grain growth and/or ejection by outflows. We provide data and tools online to facilitate community-wide high-redshift dust searches.
