Large Molecular and Dust Reservoir of a Gravitationally Lensed Submillimeter Galaxy behind the Lupus I Molecular Cloud
Journal article, 2025
We report the Australian Telescope Compact Array and Nobeyama 45 m telescope detection of a remarkably bright (S1.1mm = 44 mJy) submillimeter galaxy MM J154506.4−344318 in emission lines at 48.5 and 97.0 GHz, respectively. We also identify part of an emission line at ≈218.3 GHz using the Atacama Large Millimeter/submillimeter Array (ALMA). Together with photometric redshift estimates and the ratio between the line and infrared luminosities, we conclude that the emission lines are most likely to be the J = 2-1, 4-3, and 9-8 transitions of 12CO at redshift z = 3.753 ± 0.001. ALMA 1.3 mm continuum imaging reveals an arc and a spot separated by an angular distance of 1 . ″ 6 , indicative of a strongly lensed dusty star-forming galaxy with respective molecular and dust masses of log M mol / M ⊙ ≈ 11.5 and log M dust / M ⊙ ≈ 9.4 after being corrected for ≈6.6× gravitational magnification. The inferred dust-to-gas mass ratio is found to be high (≈0.0083) among coeval dusty star-forming galaxies, implying the presence of a massive, chemically enriched reservoir of cool interstellar medium at z ≈ 4, or 1.6 Gyr after the Big Bang.
Author
Y. Tamura
Nagoya University
Akio Taniguchi
Nagoya University
Kitami Institute of Technology
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
I. de Gregorio-Monsalvo
European Southern Observatory Santiago
Masato Hagimoto
Nagoya University
S. Ikarashi
Fukuoka Institute of Technology
National Astronomical Observatory of Japan
Nihon University
Ryohei Kawabe
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Kotaro Kohno
University of Tokyo
Research Center for the Early Universe
Kouichiro Nakanishi
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Tatsuya Takekoshi
Kitami Institute of Technology
Yoshito Shimajiri
Kyushu Kyoritsu Univ
Takashi Tsukagoshi
Ashikaga University
B. Hatsukade
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
D. Iono
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
Hideo Matsuhara
JAXA Institute of Space and Astronautical Science
The Graduate University for Advanced Studies (SOKENDAI)
Kazuya Saigo
Kagoshima University
Masao Saito
National Astronomical Observatory of Japan
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 981 1 51Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/1538-4357/adb1b9