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arXiv · 2507.13160

Stochastic star formation activity of galaxies within the first billion years probed by JWST

C. Carvajal-Bohorquez·L. Ciesla·N. Laporte·M. Boquien·V. Buat·O. Ilbert·G. Aufort·M. Shuntov·C. Witten·P. A. Oesch·A. Covelo-Paz
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Abstract

In this work, we aim at characterizing the burstiness level of high-redshift galaxy SFHs and its evolution. We implement a stochastic SFH in CIGALE using PSD, to estimate the burstiness level of star formation in galaxies at 6 6 galaxies, while smoother assumptions introduce biases when applied to galaxies with bursty star-formation activity. The assumed stochasticity level of the SFH also affects the constraints on galaxies' physical properties, including the main sequence. Successively assuming different levels of burstiness, we determined the best-suited SFH for each 6 10. Our results add further evidence that a combination with other mechanisms is likely responsible for the high-z UVLF. The stochastic SFH module is public as part of CIGALE version 2025.1.

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C. Carvajal-Bohorquez, L. Ciesla, N. Laporte, M. Boquien, V. Buat, O. Ilbert, G. Aufort, M. Shuntov, C. Witten, P. A. Oesch, A. Covelo-Paz. 2025-07-17. Stochastic star formation activity of galaxies within the first billion years probed by JWST. https://doi.org/10.1051/0004-6361%2F202556471

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