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arXiv · 2601.01697

Accelerated evolution of galaxy host halo masses during Cosmic Dawn from deep JWST clustering

Nicolò Dalmasso·Giovanni Ferrami·Nicha Leethochawalit·Emanuele M. Ventura·Michele Trenti
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Abstract

We present the deepest clustering analysis of early galaxies to date, analyzing $N_{\rm{g}} \simeq 6500$ photometrically-selected Lyman Break Galaxies from JWST's Advanced Deep Extragalactic Survey (JADES) to reveal how galaxies and dark matter evolved during cosmic dawn ($5 \leq z < 11$). Using halo occupation distribution (HOD) modeling of the two-point angular correlation function, we trace the galaxy-halo relationships across the first billion years of cosmic history. Our analysis reveals that galaxies at $z = 10.6$ reside in dark matter halos over an order of magnitude less massive ($M_{\rm{h}} \sim 10^{10.12} M_{\odot}$) than their counterparts at $z = 5.5$ ($M_{\rm{h}} \sim 10^{11.45} M_{\odot}$), while exhibiting correspondingly higher effective bias values ($b_{\rm{g}}^{\rm{eff}} = 8.13^{+0.04}_{-0.02}$ compared to $5.64^{+0.10}_{-0.13}$). Correspondingly, the satellite galaxy fraction hints at a declining trend with decreasing redshift, reaching $<1\%$ by $z \sim 5-6$. However, the significant systematic and random uncertainties in the data-model comparison prevent us from drawing robust conclusions on the evolution - if any - of the satellite fraction during the epoch of reionization. These results provide the first view of the coevolution between galaxies and dark matter evolved at redshift $\gtrsim 10$, offering additional and independent constraints on early galaxy formation models tuned to reproducing luminosity function evolution.

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Nicolò Dalmasso, Giovanni Ferrami, Nicha Leethochawalit, Emanuele M. Ventura, Michele Trenti. 2026-01-05. Accelerated evolution of galaxy host halo masses during Cosmic Dawn from deep JWST clustering. https://doi.org/10.1093/mnras/stag001

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