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Physics and Astronomy


Aims. We take advantage of the NIRCam photometric observations available as part of the Cosmic Evolution Early Release Science survey (CEERS) to identify and analyse very red sources in an effort to discover very dusty star forming galaxies. Methods. We select red galaxies as objects with a S / N > 3 at 4.4 μm and a S / N < 2 in all JWST and HST filters at λ ≤ 2 μm, which corresponds to [ F 200 W ]−[ F 444 W ]> 1.2 considering CEERS depths. This selection is ideal to identify very dusty ( A V > 1 mag) galaxies with stellar masses between 10 6 and 10 10 M ⊙ at z < 5, more massive dusty galaxies at z = 5 − 18 and galaxies at z > 18 due to the Lyman absorption, independently of their dust extinction. Results. Our sample of F 200 W -dropouts contains no strong candidates at z > 6.5, instead it consists almost completely (∼81%) of z < 2 low-mass galaxies, with a median stellar mass of 10 7.3 M ⊙ . These galaxies show an exceptional dust extinction with median value of A V = 4.9 mag, completely unexpected given their low stellar mass. The remaining galaxies, which are at z < 6.5, show similar large dust extinction ( A V > 1), but they are generally more massive > 10 7.5 M ⊙ .


© The Authors 2023

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Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Original Publication Information

"Delving deep: A population of extremely dusty dwarfs observed by JWST." L. Bisigello, G. Gandolfi, A. Grazian, G. Rodighiero, L. Costantin, A. R. Cooray, A. Feltre, C. Gruppioni, N. P. Hathi, B. W. Holwerda, A. M. Koekemoer, R. A. Lucas, J. A. Newman, P. G. Pérez-González, L. Y. A. Yung, A. de la Vega, P. Arrabal Haro, M. B. Bagley, M. Dickinson, S. L. Finkelstein, J. S. Kartaltepe, C. Papovich, N. Pirzkal, S. Wilkins, A&A 676 A76 (2023).