The Astrophysical Journal Supplement Series (Jan 2024)

ALMA Lensing Cluster Survey: Deep 1.2 mm Number Counts and Infrared Luminosity Functions at z ≃ 1–8

  • Seiji Fujimoto,
  • Kotaro Kohno,
  • Masami Ouchi,
  • Masamune Oguri,
  • Vasily Kokorev,
  • Gabriel Brammer,
  • Fengwu Sun,
  • Jorge González-López,
  • Franz E. Bauer,
  • Gabriel B. Caminha,
  • Bunyo Hatsukade,
  • Johan Richard,
  • Ian Smail,
  • Akiyoshi Tsujita,
  • Yoshihiro Ueda,
  • Ryosuke Uematsu,
  • Adi Zitrin,
  • Dan Coe,
  • Jean-Paul Kneib,
  • Marc Postman,
  • Keiichi Umetsu,
  • Claudia del P. Lagos,
  • Gergö Popping,
  • Yiping Ao,
  • Larry Bradley,
  • Karina Caputi,
  • Miroslava Dessauges-Zavadsky,
  • Eiichi Egami,
  • Daniel Espada,
  • R. J. Ivison,
  • Mathilde Jauzac,
  • Kirsten K. Knudsen,
  • Anton M. Koekemoer,
  • Georgios E. Magdis,
  • Guillaume Mahler,
  • A. M. Muñoz Arancibia,
  • Timothy Rawle,
  • Kazuhiro Shimasaku,
  • Sune Toft,
  • Hideki Umehata,
  • Francesco Valentino,
  • Tao Wang,
  • Wei-Hao Wang

DOI
https://doi.org/10.3847/1538-4365/ad5ae2
Journal volume & issue
Vol. 275, no. 2
p. 36

Abstract

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We present a statistical study of 180 dust continuum sources identified in 33 massive cluster fields by the Atacama Large Millimeter/submillimeter Array Lensing Cluster Survey (ALCS) over a total of 133 arcmin ^2 area, homogeneously observed at 1.2 mm. ALCS enables us to detect extremely faint millimeter sources by lensing magnification, including near-infrared (NIR) dark objects showing no counterparts in existing Hubble Space Telescope and Spitzer images. The dust continuum sources belong to a blind sample ( N = 141) with signal-to-noise ratio (S/N) ≳ 5.0 (a purity of >0.99) or a secondary sample ( N = 39) with S/N = 4.0–5.0 screened by priors. With the blind sample, we securely derive 1.2 mm number counts down to ∼7 μ Jy, and find that the total integrated 1.2 mm flux is ${20.7}_{-6.5}^{+8.5}$ Jy deg ^−2 , resolving ≃80% of the cosmic infrared background light. The resolved fraction varies by a factor of 0.6–1.1 due to the completeness correction depending on the spatial size of the millimeter emission. We also derive infrared (IR) luminosity functions (LFs) at z = 0.6–7.5 with the $1/{V}_{\max }$ method, finding the redshift evolution of IR LFs characterized by positive luminosity and negative density evolution. The total (= UV + IR) cosmic star formation rate density (SFRD) at z > 4 is estimated to be ${161}_{-21}^{+25}$ % of the Madau and Dickinson measurements mostly based on rest-frame UV surveys. Although our general understanding of the cosmic SFRD is unlikely to change beyond a factor of 2, these results add to the weight of evidence for an additional (≈60%) SFRD component contributed by the faint millimeter population, including NIR-dark objects.

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