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Overdensity of Lyman-break galaxy candidates around hot-dust-obscured galaxies
Journal article   Open access   Peer reviewed

Overdensity of Lyman-break galaxy candidates around hot-dust-obscured galaxies

Dejene Zewdie, Roberto J. Assef, Trystan Lambert, Chiara Mazzucchelli, S. Ilani Loubser, Manuel Aravena, Jorge Gonzalez-Lopez, Hyunsung D. Jun, Chao-Wei Tsai, Daniel Stern, …
Astronomy and astrophysics (Berlin), Vol.694, 121
02-11-2025

Abstract

Astronomy & Astrophysics Physical Sciences Science & Technology
Hot dust-obscured galaxies (hot DOGs) are a family of hyper-luminous, heavily obscured quasars. A number of studies based on the identification of companions at optical to far-infrared (FIR) wavelengths have shown that these objects reside in significantly overdense regions of the Universe. Here we present further characterisation of their environments by studying the surface density of Lyman break galaxy (LBG) candidates in the vicinity of three hot DOGs. For two of them, WISE J041010.60-091305.2 (W0410-0913) at z = 3.631 and WISE J083153.25+014010.8 (W0831+0140) at z = 3.912, we identify the candidate LBG companions using deep observations obtained with Baade/IMACS. For the third, WISE J224607.56-052634.9 (W2246-0526) at z = 4.601, we reanalyse previously published data obtained with Gemini-S/GMOS-S. We optimise the LBG photometric selection criteria at the redshift of each target using the COSMOS2020 catalog. When comparing the density of LBG candidates found in the vicinity of these hot DOGs with that in the COSMOS2020 catalog, we find overdensities of delta = 1.83 +/- 0.08 (delta ' = 7.49 +/- 0.68), delta = 4.67 +/- 0.21 (delta ' = 29.17 +/- 2.21), and delta = 2.36 +/- 0.25 (delta ' = 11.60 +/- 1.96) around W0410-0913, W0831+0140, and W2246-0526, respectively, without (with) contamination correction. Additionally, we find that the overdensities are centrally concentrated around each hot DOG. Our analysis also reveals that the overdensity of the fields surrounding W0410-0913 and W0831+0140 declines steeply beyond physical scales of similar to 2 Mpc. If these overdensities evolve into clusters by z = 0, the present results suggest that the hot DOG may correspond to the early formation stages of the brightest cluster galaxy. We were unable to determine whether or not this is also the case for W2246-0526 due to the smaller field of view (FOV) of the GMOS-S observations. Our results imply that hot DOGs may be excellent tracers of protoclusters.
url
http://arxiv.org/pdf/2412.04436View
Open
url
https://doi.org/10.1051/0004-6361/202451403View
Published (Version of record) Open

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