SERENADE. II. An ALMA Multiband Dust Continuum Analysis of 28 Galaxies at 5 < z < 8 and the Physical Origin of the Dust Temperature Evolution
Artikel i vetenskaplig tidskrift, 2024

We present an analysis of the Atacama Large Millimeter-submillimeter Array (ALMA) multiband dust continuum observations for 28 spectroscopically confirmed bright Lyman break galaxies at 5 < z < 8. Our sample consists of 11 galaxies at z ∼ 6 newly observed in our ALMA program, which substantially increases the number of 5 < z < 8 galaxies with both rest-frame 88 and 158 μm continuum observations, allowing us to simultaneously measure the IR luminosity and dust temperature for a statistical sample of z ≳ 5 galaxies for the first time. We derive the relationship between the ultraviolet (UV) slope (β UV) and infrared excess (IRX) for the z ∼ 6 galaxies, and find a shallower IRX-β UV relation compared to the previous results at z ∼ 2-4. Based on the IRX-β UV relation consistent with our results and the β UV-M UV relation including fainter galaxies in the literature, we find a limited contribution of the dust-obscured star formation to the total star formation rate density, ∼30% at z ∼ 6. Our measurements of the dust temperature at z ∼ 6-7, T dust = 40.9 − 9.1 + 10.0 K on average, support a gentle increase of T dust from z = 0 to z ∼ 6-7. Using an analytic model with parameters consistent with recent James Webb Space Telescope results, we discuss that the observed redshift evolution of the dust temperature can be reproduced by an ∼0.6 dex decrease in the gas depletion timescale and ∼0.4 dex decrease in the metallicity. The variety of T dust observed at high redshifts can also be naturally explained by scatters around the star formation main sequence and average mass-metallicity relation including an extremely high dust temperature of T dust > 80 K observed in a galaxy at z = 8.3.

Författare

Ikki Mitsuhashi

University of Tokyo

National Astronomical Observatory of Japan

Waseda University

Yuichi Harikane

University of Tokyo

F. E. Bauer

Instituto Milenio de Astrofísica

Space Science Institute

Pontificia Universidad Catolica de Chile

Tom Bakx

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

Andrea Ferrara

Scuola Normale Superiore di Pisa

S. Fujimoto

The University of Texas at Austin

Takuya Hashimoto

University of Tsukuba

Akio K. Inoue

Waseda University

K. Iwasawa

Institucio Catalana de Recerca i Estudis Avancats

Universitat de Barcelona

Y. Nishimura

University of Tokyo

M. Imanishi

National Astronomical Observatory of Japan

Yoshiaki Ono

University of Tokyo

T. Saito

National Astronomical Observatory of Japan

Yuma Sugahara

Waseda University

National Astronomical Observatory of Japan

H. Umehata

California Institute of Technology (Caltech)

Nagoya University

L. Vallini

Istituto nazionale di astrofisica (INAF)

T. Wang

Nanjing University

J. A. Zavala

National Astronomical Observatory of Japan

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 971 2 161

Ämneskategorier

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

DOI

10.3847/1538-4357/ad5675

Mer information

Senast uppdaterat

2024-08-23