ALMA Lensing Cluster Survey: Physical Characterization of Near-infrared-dark Intrinsically Faint ALMA Sources at z = 2-4
Artikel i vetenskaplig tidskrift, 2025

We present results from Atacama Large Millimeter/submillimeter Array (ALMA) spectral line-scan observations at 3 mm and 2 mm bands of three near-infrared-dark (NIR-dark) galaxies behind two massive lensing clusters MACS J0417.5-1154 and RXC J0032.1+1808. Each of these three sources is a (sub)millimeter faint (delensed S1.2 mm < 1 mJy) triply lensed system originally discovered in the ALMA Lensing Cluster Survey. We have successfully detected CO and [C i] emission lines and confirmed that their spectroscopic redshifts are z = 3.652, 2.391, and 2.985. By utilizing a rich multiwavelength data set, we find that the NIR-dark galaxies are located on the star formation main sequence in the intrinsic stellar mass range of log (M*/M⊙) = 9.8-10.4, which is about 1 order of magnitude lower than that of typical submillimeter galaxies (SMGs). These NIR-dark galaxies show a variety in gas depletion times and spatial extent of dust emission. One of the three is a normal star-forming galaxy with gas depletion time consistent with a scaling relation, and its infrared surface brightness is an order of magnitude smaller than that of typical SMGs. Since this galaxy has an elongated axis ratio of ∼0.17, we argue that normal star-forming galaxies in an edge-on configuration can be heavily dust-obscured. This implies that existing deep WFC3/F160W surveys may miss a fraction of typical star-forming main-sequence galaxies due to their edge-on orientation.

Författare

Akiyoshi Tsujita

University of Tokyo

Kotaro Kohno

Research Center for the Early Universe

University of Tokyo

Shuo Huang

Nagoya University

National Astronomical Observatory of Japan

M. Oguri

Chiba University

Ken Ichi Tadaki

Hokkai Gakuen University

I. Smail

Durham University

H. Umehata

Nagoya University

California Institute of Technology (Caltech)

Zhen Kai Gao

National Central University

Academia Sinica

Wei Hao Wang

Academia Sinica

Fengwu Sun

University of Arizona

Harvard-Smithsonian Center for Astrophysics

S. Fujimoto

Cosmic Dawn Center (DAWN)

University of Texas

Niels Bohr Institute

T. Wang

Nanjing University

Ryosuke Uematsu

Kyoto University

D. Espada

Universidad de Granada

F. Valentino

Cosmic Dawn Center (DAWN)

European Southern Observatory (ESO)

Y. Ao

University of Science and Technology of China

Chinese Academy of Sciences

F. E. Bauer

Pontificia Universidad Catolica de Chile

Instituto Milenio de Astrofísica

B. Hatsukade

National Astronomical Observatory of Japan

University of Tokyo

The Graduate University for Advanced Studies (SOKENDAI)

Fumi Egusa

University of Tokyo

Y. Nishimura

University of Tokyo

Anton M. Koekemoer

Space Telescope Science Institute (STScI)

D. Schaerer

Université de Genève

Institut de Recherche en Astrophysique et Planétologie (IRAP)

C. D. P. Lagos

University of Western Australia

Cosmic Dawn Center (DAWN)

ARC Centre of Excellence for All-sky Astrophysics

M. Dessauges-Zavadsky

Université de Genève

G. Brammer

Niels Bohr Institute

Cosmic Dawn Center (DAWN)

Karina I. Caputi

Rijksuniversiteit Groningen

Cosmic Dawn Center (DAWN)

Eiichi Egami

University of Arizona

J. González-López

Universidad Diego Portales

Las Campanas Observatory

Jean Baptiste Jolly

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

Max-Planck-Gesellschaft

Kirsten Knudsen

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

V. Kokorev

Cosmic Dawn Center (DAWN)

Niels Bohr Institute

Rijksuniversiteit Groningen

Georgios E. Magdis

Niels Bohr Institute

Cosmic Dawn Center (DAWN)

Danmarks Tekniske Universitet (DTU)

Masami Ouchi

University of Tokyo

National Astronomical Observatory of Japan

Sune Toft

Cosmic Dawn Center (DAWN)

Niels Bohr Institute

John F. Wu

Space Telescope Science Institute (STScI)

Johns Hopkins University

A. Zitrin

Ben-Gurion University of the Negev

Astrophysical Journal

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

Vol. 989 1 115

Ämneskategorier (SSIF 2025)

Atom- och molekylfysik och optik

Annan fysik

Astronomi, astrofysik och kosmologi

DOI

10.3847/1538-4357/adb41d

Mer information

Senast uppdaterat

2026-01-07