Extensive Lensing Survey of Optical and Near-infrared Dark Objects (El Sonido): HST H-faint Galaxies behind 101 Lensing Clusters
Journal article, 2021
We present a Spitzer/IRAC survey of H-faint (H-160 greater than or similar to 26.4, < 5 sigma) sources in 101 lensing cluster fields. Across a CANDELS/Wide-like survey area of similar to 648 arcmin(2) (effectively similar to 221 arcmin(2) in the source plane), we have securely discovered 53 sources in the IRAC Channel-2 band (CH2, 4.5 mu m; median CH2 = 22.46 +/- 0.11 AB mag) that lack robust HST/WFC3-IR F160W counterparts. The most remarkable source in our sample, namely ES-009 in the field of Abell 2813, is the brightest H-faint galaxy at 4.5 mu m known so far (CH2 = 20.48 +/- 0.03 AB mag). We show that the H-faint sources in our sample are massive (median M-star = 10 10.3 +/- 0.3 M-circle dot, star-forming (median star formation rate =1001 M-circle dot yr(-1)), and dust-obscured (A(v) = 2.6 +/- 0.3) galaxies around a median photometric redshift of z = 3.9 +/- 0.4. The stellar continua of 14 H-faint galaxies can be resolved in the CH2 band, suggesting a median circularized effective radius (R-e,R-circ; lensing corrected) of 1.9 +/- 0.2 kpc and <1.5 kpc for the resolved and whole samples, respectively. This is consistent with the sizes of massive unobscured galaxies at z similar to 4, indicating that H-faint galaxies represent the dusty tail of the distribution of a wider galaxy population. Comparing with the ALMA dust continuum sizes of similar galaxies reported previously, we conclude that the heavy dust obscuration in H-faint galaxies is related to the compactness of both stellar and dust continua (R-e,R-circ similar to 1 kpc). These H-faint galaxies make up 161 3 % of the galaxies in the stellar-mass range of 10(10) - 10(11.2) M-circle dot at z = 3 similar to 5, contributing to 8(-4)(+8)% of the cosmic star formation rate density in this epoch and likely tracing the early phase of massive galaxy formation.
Author
Fengwu Sun
University of Arizona
Eiichi Egami
University of Arizona
Pablo G. Perez-Gonzalez
Spanish National Research Council (CSIC)
Ian Smail
Durham University
Karina I. Caputi
University of Groningen
University of Copenhagen
Franz E. Bauer
Millennium Institute of Astrophysics
Pontificia Universidad Catolica de Chile
Timothy D. Rawle
Space Telescope Science Institute (STScI)
Seiji Fujimoto
University of Copenhagen
Kotaro Kohno
University of Tokyo
Ugne Dudzeviciute
Durham University
Hakim Atek
Sorbonne University
Matteo Bianconi
University of Birmingham
Scott C. Chapman
Eureka Scientific
Francoise Combes
Collège de France
Sorbonne University
Mathilde Jauzac
Durham University
University of KwaZulu-Natal
Jean Baptiste Jolly
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Anton M. Koekemoer
Space Telescope Science Institute (STScI)
Georgios E. Magdis
Technical University of Denmark (DTU)
University of Copenhagen
Giulia Rodighiero
University of Padua
Istituto nazionale di astrofisica (INAF)
Wiphu Rujopakarn
Chulalongkorn University
National Astronomical Research Institute of Thailand
University of Tokyo
Daniel Schaerer
University of Geneva
Charles L. Steinhardt
University of Copenhagen
Paul Van der Werf
Leiden University
Gregory L. Walth
Carnegie Observatories
John R. Weaver
University of Copenhagen
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 922 2 114Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Other Earth and Related Environmental Sciences
Geosciences, Multidisciplinary
DOI
10.3847/1538-4357/ac2578