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

TL;DR

This study uses deep JWST clustering data to analyze galaxy-halo relationships during cosmic dawn, revealing rapid evolution in halo masses and bias from redshift 11 to 5, with implications for early galaxy formation.

Contribution

It provides the first detailed clustering analysis of early galaxies at redshifts 5 to 11, revealing how galaxy-halo connections evolved during cosmic dawn.

Findings

Galaxies at z=10.6 reside in halos over ten times less massive than at z=5.5.

Effective galaxy bias increases significantly from z=11 to z=5.

Satellite galaxy fraction declines to less than 1% by z~5-6.

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.