The clustering of typical Ly$\alpha$ emitters from $z\sim 2.5-6$: host halo masses depend on Ly$\alpha$ and UV luminosities

Abstract

We investigate the clustering and halo properties of $\sim 5000$ Ly$\alpha$-selected emission line galaxies (LAEs) from the Slicing COSMOS 4K (SC4K) and from archival NB497 imaging of SA22 split in 15 discrete redshift slices between $z\sim 2.5-6$. We measure clustering lengths of $r_0\sim 3-6h^{-1}$ Mpc and typical halo masses of $\sim 10^{11}$ M${}_{\odot }$ for our narrowband-selected LAEs with typical $L_{\mathrm{Ly}\alpha }\sim 10^{42-43}$ erg s${}^{-1}$. The intermediate band-selected LAEs are observed to have $r_0\sim 3.5-15h^{-1}$ Mpc with typical halo masses of $\sim 10^{11-12}$ M${}_{\odot }$ and typical $L_{\mathrm{Ly}\alpha }\sim 10^{43-43.6}$ erg s${}^{-1}$. We find a strong, redshift-independent correlation between halo mass and Ly$\alpha$ luminosity normalized by the characteristic Ly$\alpha$ luminosity, $L^{\star }(z)$. The faintest LAEs ($L\sim 0.1L^{\star }(z)$) typically identified by deep narrowband surveys are found in $10^{10}$ M${}_{\odot }$ halos and the brightest LAEs ($L\sim 7L^{\star }(z)$) are found in $\sim 5\times 10^{12}$ M${}_{\odot }$ halos. A dependency on the rest-frame 1500 Å~UV luminosity, M$_\rm{UV}$, is also observed where the halo masses increase from $10^{11}$ to $10^{13}$ M${}_{\odot }$ for M$_\rm{UV} \sim -19$ to $-23.5$ mag. Halo mass is also observed to increase from $10^{9.8}$ to $10^{12.3}$ M${}_{\odot }$ for dust-corrected UV star formation rates from $\sim 0.6$ to $10$ M${}_{\odot }$ yr${}^{-1}$ and continues to increase up to $10^{13.5}$ M${}_{\odot }$ in halo mass, where the majority of those sources are AGN. All the trends we observe are found to be redshift-independent. Our results reveal that LAEs are the likely progenitors of a wide range of galaxies depending on their luminosity, from dwarf-like, to Milky Way-type, to bright cluster galaxies. LAEs therefore provide unique insight into the early formation and evolution of the galaxies we observe in the local Universe.

19 pages, 13 figures, 3 tables, submitted to MNRAS. Comments are welcomed