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arXiv · 2302.10934

COSMOS2020: Exploring the dawn of quenching for massive galaxies at 3 < z < 5 with a new colour selection method

Katriona M. L. Gould·Gabriel Brammer·Francesco Valentino·Katherine E. Whitaker·John R. Weaver·Claudia del P. Lagos·Francesca Rizzo·Maximilien Franco·Bau-Ching Hseih·Olivier Ilbert·Shuowen Jin·Georgios Magdis·Henry J. McCracken·Bahram Mobasher·Marko Shuntov·Charles L. Steinhardt·Victoria Strait·Sune Toft
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Abstract

We select and characterise a sample of massive (log(M$_{*}/$M$_{\odot})>10.6$) quiescent galaxies (QGs) at $3 3$. We compute median rest-frame SEDs for our sample and find the median quiescent galaxy at $3<z<5$ has a strong Balmer/4000 Angstrom break, and residual $NUV$ flux indicating recent quenching. We find the number densities of the entire quiescent population (including post-starbursts) more than doubles from $3.5\pm2.2\times10^{-6}$ Mpc$^{-3}$ at $4<z<5$ to $1.4\pm0.4\times10^{-5}$ Mpc$^{-3}$ at $3<z<4$, confirming that the onset of massive galaxy quenching occurs as early as $3<z<5$.

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Katriona M. L. Gould, Gabriel Brammer, Francesco Valentino, Katherine E. Whitaker, John R. Weaver, Claudia del P. Lagos, Francesca Rizzo, Maximilien Franco, Bau-Ching Hseih, Olivier Ilbert, Shuowen Jin, Georgios Magdis, Henry J. McCracken, Bahram Mobasher, Marko Shuntov, Charles L. Steinhardt, Victoria Strait, Sune Toft. 2023-02-21. COSMOS2020: Exploring the dawn of quenching for massive galaxies at 3 < z < 5 with a new colour selection method. https://doi.org/10.3847/1538-3881%2Faccadc

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