A warm ultraluminous infrared galaxy just 600 million years after the big bang

Bakx, TJLC, Sommovigo, L, Tamura, Y, Smit, R ORCID: 0000-0001-8034-7802, Ferrara, A, Algera, H, Aalto, S, Bossion, D, Carniani, S, Esmerian, C, Hagimoto, M, Hashimoto, T, Hatsukade, B, Ibar, E, Inami, H, Inoue, AK, Knudsen, K, Laporte, N, Mawatari, K, Molina, J et al (2025) A warm ultraluminous infrared galaxy just 600 million years after the big bang. Monthly Notices of the Royal Astronomical Society, 544 (2). pp. 1502-1513. ISSN 0035-8711

Preview

Text A warm ultraluminous infrared galaxy just 600 million years after the big bang.pdf - Published Version Available under License Creative Commons Attribution. Download (2MB) | Preview

Abstract

We present an Atacama Large Millimeter/submillimeter Array (ALMA) Band 9 continuum detection () of MACS0416_Y1 that confirms the suspected warm dust (91 K) of this Lyman-Break Galaxy (LBG) at with M. A modified blackbody fit to the ALMA Bands 3 through 9 data of MACS0416_Y1 finds an intrinsic infrared luminosity of 1.0, placing this UV-selected LBG in the regime of Ultra Luminous Infrared Galaxies. Its luminous but modest dust reservoir (1.4) is cospatial to regions with a UV-continuum slope as seen by James Webb Space Telescope (JWST) imaging. Although this implies some dust obscuration, the JWST photometry implies less obscured star formation than seen in the complete characterization by ALMA, implying some spatial separation of dust and stars on scales below 200 pc, i.e. smaller than those probed by JWST and ALMA. This source is an extreme example of dust-obscured star formation contributing strongly to the cosmic build-up of stellar mass, which can only be revealed through direct and comprehensive observations in the (sub)mm regime.

Item Type:	Article
Uncontrolled Keywords:	5109 Space Sciences; 51 Physical Sciences; 5101 Astronomical Sciences; 0201 Astronomical and Space Sciences; Astronomy & Astrophysics; 5101 Astronomical sciences; 5107 Particle and high energy physics; 5109 Space sciences
Subjects:	Q Science > QB Astronomy Q Science > QC Physics
Divisions:	Astrophysics Research Institute
Publisher:	Oxford University Press
Date of acceptance:	4 October 2025
Date of first compliant Open Access:	27 February 2026
Date Deposited:	27 Feb 2026 13:42
Last Modified:	27 Feb 2026 13:42
DOI or ID number:	10.1093/mnras/staf1714
URI:	https://researchonline.ljmu.ac.uk/id/eprint/28154

View Item