_version_ 1866908480779059200
author Franco, Maximilien
Casey, Caitlin M.
Akins, Hollis B.
Ilbert, Olivier
Shuntov, Marko
Finkelstein, Steven L.
Paquereau, Louise
Faisst, Andreas L.
Koekemoer, Anton M.
Hirschmann, Michaela
Cantarella, Sebastiano
Drakos, Nicole E.
Wilkins, Stephen M.
McCracken, Henry Joy
Kartaltepe, Jeyhan S.
Maraston, Claudia
Abedini, Fatemeh
Achenbach, Mark J.
Arango-Toro, Rafael C.
Gentile, Fabrizio
Gozaliasl, Ghassem
Inayoshi, Kohei
Kakkad, Darshan
Kalantari, Atousa
Khostovan, Ali Ahmad
Kokorev, Vasily
Lambrides, Erini
Leroy, Gavin
Massey, Richard
Mobasher, Bahram
Newman, Sophie L.
Rhodes, Jason
Rich, R. Michael
Robertson, Brant E.
Sanders, David B.
Tanaka, Takumi S.
Vijayan, Aswin P.
Weaver, John R.
Yang, Lilan
Yu, Si-Yue
author_facet Franco, Maximilien
Casey, Caitlin M.
Akins, Hollis B.
Ilbert, Olivier
Shuntov, Marko
Finkelstein, Steven L.
Paquereau, Louise
Faisst, Andreas L.
Koekemoer, Anton M.
Hirschmann, Michaela
Cantarella, Sebastiano
Drakos, Nicole E.
Wilkins, Stephen M.
McCracken, Henry Joy
Kartaltepe, Jeyhan S.
Maraston, Claudia
Abedini, Fatemeh
Achenbach, Mark J.
Arango-Toro, Rafael C.
Gentile, Fabrizio
Gozaliasl, Ghassem
Inayoshi, Kohei
Kakkad, Darshan
Kalantari, Atousa
Khostovan, Ali Ahmad
Kokorev, Vasily
Lambrides, Erini
Leroy, Gavin
Massey, Richard
Mobasher, Bahram
Newman, Sophie L.
Rhodes, Jason
Rich, R. Michael
Robertson, Brant E.
Sanders, David B.
Tanaka, Takumi S.
Vijayan, Aswin P.
Weaver, John R.
Yang, Lilan
Yu, Si-Yue
contents We present measurements of the rest-frame ultraviolet luminosity function (UVLF) in three redshift bins over $z\sim5.5$-14 from the JWST COSMOS-Web survey. Our samples, selected using the dropout technique in the HST/ACS F814W, JWST/NIRCam F115W, and F150W filters, contain a total of 3099 galaxies spanning a wide luminosity range from faint ($M_{\rm UV}\sim-19$ mag) to bright ($M_{\rm UV}\sim-22.5$ mag). The galaxies are undergoing rapid star formation, with blue stellar populations. Surprisingly, their median UV spectral slope $β$ does not evolve at $z>8$, suggesting minimal dust, or physical separation of dust and star formation at early epochs. The measured UVLF exhibits an excess at the bright-end ($M_{\rm UV}<-21$ mag) compared to pre-JWST empirical results and theoretical predictions of an evolving Schechter function, with the excess beginning at $z\sim9$ and becoming increasingly prominent toward $z\sim12$. Our analysis suggests that reproducing the observed abundance of UV-bright galaxies at high redshift requires a combination of physical processes, including elevated star formation efficiencies, moderate levels of stochasticity in galaxy luminosities, and minimal dust attenuation.
format Preprint
id arxiv_https___arxiv_org_abs_2508_04791
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Physical properties of galaxies and the UV Luminosity Function from $z\sim6$ to $z\sim14$ in COSMOS-Web
Franco, Maximilien
Casey, Caitlin M.
Akins, Hollis B.
Ilbert, Olivier
Shuntov, Marko
Finkelstein, Steven L.
Paquereau, Louise
Faisst, Andreas L.
Koekemoer, Anton M.
Hirschmann, Michaela
Cantarella, Sebastiano
Drakos, Nicole E.
Wilkins, Stephen M.
McCracken, Henry Joy
Kartaltepe, Jeyhan S.
Maraston, Claudia
Abedini, Fatemeh
Achenbach, Mark J.
Arango-Toro, Rafael C.
Gentile, Fabrizio
Gozaliasl, Ghassem
Inayoshi, Kohei
Kakkad, Darshan
Kalantari, Atousa
Khostovan, Ali Ahmad
Kokorev, Vasily
Lambrides, Erini
Leroy, Gavin
Massey, Richard
Mobasher, Bahram
Newman, Sophie L.
Rhodes, Jason
Rich, R. Michael
Robertson, Brant E.
Sanders, David B.
Tanaka, Takumi S.
Vijayan, Aswin P.
Weaver, John R.
Yang, Lilan
Yu, Si-Yue
Astrophysics of Galaxies
We present measurements of the rest-frame ultraviolet luminosity function (UVLF) in three redshift bins over $z\sim5.5$-14 from the JWST COSMOS-Web survey. Our samples, selected using the dropout technique in the HST/ACS F814W, JWST/NIRCam F115W, and F150W filters, contain a total of 3099 galaxies spanning a wide luminosity range from faint ($M_{\rm UV}\sim-19$ mag) to bright ($M_{\rm UV}\sim-22.5$ mag). The galaxies are undergoing rapid star formation, with blue stellar populations. Surprisingly, their median UV spectral slope $β$ does not evolve at $z>8$, suggesting minimal dust, or physical separation of dust and star formation at early epochs. The measured UVLF exhibits an excess at the bright-end ($M_{\rm UV}<-21$ mag) compared to pre-JWST empirical results and theoretical predictions of an evolving Schechter function, with the excess beginning at $z\sim9$ and becoming increasingly prominent toward $z\sim12$. Our analysis suggests that reproducing the observed abundance of UV-bright galaxies at high redshift requires a combination of physical processes, including elevated star formation efficiencies, moderate levels of stochasticity in galaxy luminosities, and minimal dust attenuation.
title Physical properties of galaxies and the UV Luminosity Function from $z\sim6$ to $z\sim14$ in COSMOS-Web
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2508.04791