Paper

ALMA Lensing Cluster Survey: Deep 1.2 mm Number Counts and Infrared Luminosity Functions at \\(z\\simeq1-8\\)

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

2024

Overview

We present a statistical study of 180 dust continuum sources identified in 33 massive cluster fields by the ALMA 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 mm sources by lensing magnification, including near-infrared (NIR) dark objects showing no counterparts in existing {\\it Hubble Space Telescope} and {\\it Spitzer} images. The dust continuum sources belong to a blind sample (\\(N=141\\)) with S/N \\(\\gtrsim\\) 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 \\(\\sim7\\) \\(\\mu\\)Jy, and find that the total integrated 1.2mm flux is 20.7\\(^{+8.5}_{-6.5}\\) Jy deg\\(^{-2}\\), resolving \\(\\simeq\\) 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 mm emission. We also derive infrared (IR) luminosity functions (LFs) at \\(z=0.6-7.5\\) with the \\(1/V_{\\rm 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^{+25}_{-21}\\) % of the established measurements, which were almost exclusively based on optical\\(-\\)NIR 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 (\\(\\approx 60\\) %) SFRD component contributed by the faint-mm population, including NIR dark objects.

• Publisher: Cornell University Library, arXiv.org
• Subject: Clusters / Density / Dust / Evolution / Hubble Space Telescope / Luminosity / Near infrared radiation / Red shift / Space telescopes / Star formation