_version_ 1866915235618619392
author Yang, Lilan
Kartaltepe, Jeyhan S.
Franco, Maximilien
Ding, Xuheng
Achenbach, Mark J.
Arango-Toro, Rafael C.
Casey, Caitlin M.
Drakos, Nicole E.
Faisst, Andreas L.
Gillman, Steven
Gozaliasl, Ghassem
Huertas-Company, Marc
Jin, Shuowen
Liu, Daizhong
Magdis, Georgios
Massey, Richard
Silverman, John D.
Tanaka, Takumi S.
Yu, Si-Yue
Akins, Hollis B.
Allen, Natalie
Ilbert, Olivier
Koekemoer, Anton M.
McCracken, Henry Joy
Paquereau, Louise
Rhodes, Jason
Robertson, Brant E.
Shuntov, Marko
Toft, Sune
author_facet Yang, Lilan
Kartaltepe, Jeyhan S.
Franco, Maximilien
Ding, Xuheng
Achenbach, Mark J.
Arango-Toro, Rafael C.
Casey, Caitlin M.
Drakos, Nicole E.
Faisst, Andreas L.
Gillman, Steven
Gozaliasl, Ghassem
Huertas-Company, Marc
Jin, Shuowen
Liu, Daizhong
Magdis, Georgios
Massey, Richard
Silverman, John D.
Tanaka, Takumi S.
Yu, Si-Yue
Akins, Hollis B.
Allen, Natalie
Ilbert, Olivier
Koekemoer, Anton M.
McCracken, Henry Joy
Paquereau, Louise
Rhodes, Jason
Robertson, Brant E.
Shuntov, Marko
Toft, Sune
contents We measure galaxy sizes from $2 < z < 10$ using COSMOS-Web, the largest-area JWST imaging survey to date, covering $\sim$0.54 deg$^2$. We analyze the rest-frame optical (~5000A) size evolution and its scaling relation with stellar mass ($R_e\propto M_*^α$) for star-forming and quiescent galaxies. For star-forming galaxies, the slope $α$ remains approximately 0.20 at $2 < z < 8$, showing no significant evolution over this redshift range. At higher redshifts, the slopes are $-0.13 \pm 0.15$ and $0.37 \pm 0.36$ for $8 < z < 9$ and $9 < z < 10$, respectively. At fixed galaxy mass, the size evolution for star-forming galaxies follows $R_e \propto (1+z)^{-β}$, with $β= 1.21 \pm 0.05$. For quiescent galaxies, the slope is steeper $α\sim 0.5$-$0.8$ at $2 < z < 5$, and $β=0.81\pm0.26$. We find that the size-mass relation is consistent between UV and optical at $z < 8$ for star-forming galaxies. However, we observe a decrease in the slope from UV to optical at $z > 8$, with a tentative negative slope in the optical at $8 < z < 9$, suggesting a complex interplay between intrinsic galaxy properties and observational effects such as dust attenuation. We discuss the ratio between galaxies' half-light radius, and underlying halos' virial radius, $R_{vir}$, and find the median value of $R_e/R_{vir}=2.7\%$. The star formation rate surface density evolves as $\logΣ_\text{SFR} = (0.20\pm0.08)\,z+(-0.65\pm0.51)$, and the $Σ_\text{SFR}$-$M_*$ relation remains flat at $2<z<10$. Lastly, we identify a threshold in stellar mass surface density $\logΣ_e\sim9.5$-$10\, M_{\odot}/kpc^2$ marking the transition to compact, quenched galaxies from extended, star-forming progenitors. In summary, our findings show that the extensive COSMOS-Web dataset at $z > 3$ provides new insights into galaxy size and related properties in the rest-frame optical.
format Preprint
id arxiv_https___arxiv_org_abs_2504_07185
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle COSMOS-Web: Unraveling the Evolution of Galaxy Size and Related Properties at $2<z<10$
Yang, Lilan
Kartaltepe, Jeyhan S.
Franco, Maximilien
Ding, Xuheng
Achenbach, Mark J.
Arango-Toro, Rafael C.
Casey, Caitlin M.
Drakos, Nicole E.
Faisst, Andreas L.
Gillman, Steven
Gozaliasl, Ghassem
Huertas-Company, Marc
Jin, Shuowen
Liu, Daizhong
Magdis, Georgios
Massey, Richard
Silverman, John D.
Tanaka, Takumi S.
Yu, Si-Yue
Akins, Hollis B.
Allen, Natalie
Ilbert, Olivier
Koekemoer, Anton M.
McCracken, Henry Joy
Paquereau, Louise
Rhodes, Jason
Robertson, Brant E.
Shuntov, Marko
Toft, Sune
Astrophysics of Galaxies
We measure galaxy sizes from $2 < z < 10$ using COSMOS-Web, the largest-area JWST imaging survey to date, covering $\sim$0.54 deg$^2$. We analyze the rest-frame optical (~5000A) size evolution and its scaling relation with stellar mass ($R_e\propto M_*^α$) for star-forming and quiescent galaxies. For star-forming galaxies, the slope $α$ remains approximately 0.20 at $2 < z < 8$, showing no significant evolution over this redshift range. At higher redshifts, the slopes are $-0.13 \pm 0.15$ and $0.37 \pm 0.36$ for $8 < z < 9$ and $9 < z < 10$, respectively. At fixed galaxy mass, the size evolution for star-forming galaxies follows $R_e \propto (1+z)^{-β}$, with $β= 1.21 \pm 0.05$. For quiescent galaxies, the slope is steeper $α\sim 0.5$-$0.8$ at $2 < z < 5$, and $β=0.81\pm0.26$. We find that the size-mass relation is consistent between UV and optical at $z < 8$ for star-forming galaxies. However, we observe a decrease in the slope from UV to optical at $z > 8$, with a tentative negative slope in the optical at $8 < z < 9$, suggesting a complex interplay between intrinsic galaxy properties and observational effects such as dust attenuation. We discuss the ratio between galaxies' half-light radius, and underlying halos' virial radius, $R_{vir}$, and find the median value of $R_e/R_{vir}=2.7\%$. The star formation rate surface density evolves as $\logΣ_\text{SFR} = (0.20\pm0.08)\,z+(-0.65\pm0.51)$, and the $Σ_\text{SFR}$-$M_*$ relation remains flat at $2<z<10$. Lastly, we identify a threshold in stellar mass surface density $\logΣ_e\sim9.5$-$10\, M_{\odot}/kpc^2$ marking the transition to compact, quenched galaxies from extended, star-forming progenitors. In summary, our findings show that the extensive COSMOS-Web dataset at $z > 3$ provides new insights into galaxy size and related properties in the rest-frame optical.
title COSMOS-Web: Unraveling the Evolution of Galaxy Size and Related Properties at $2<z<10$
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2504.07185