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The clustering of typical Ly α emitters from z ∼ 2.5–6: host halo masses depend on Ly α and UV luminosities

A. A. Khostovan, D. Sobral, B. Mobasher, J. Matthee, R. K. Cochrane, N. Chartab, M. Jafariyazani, A. Paulino-Afonso, S. Santos, J. Calhau

We investigate the clustering and halo properties of ∼5000 Ly α-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 ∼ 2.5 and 6. We measure clustering lengths of r0 ∼ 3–6 h−1 Mpc and typical halo masses of ∼1011 M⊙ for our narrowband-selected LAEs with typical LLy α ∼ 1042–43 erg s−1. The intermediate-band-selected LAEs are observed to have r0 ∼ 3.5–15 h−1 Mpc with typical halo masses of ∼1011–12 M and typical LLy α ∼ 1043–43.6 erg s−1. We find a strong, redshift-independent correlation between halo mass and Ly α luminosity normalized by the characteristic Ly α luminosity, L⋆(z). The faintest LAEs (L ∼ 0.1 L⋆(z)) typically identified by deep narrowband surveys are found in 1010 M haloes and the brightest LAEs (L ∼ 7 L⋆(z)) are found in ∼5 × 1012 M haloes. A dependency on the rest-frame 1500 Å UV luminosity, MUV, is also observed where the halo masses increase from 1011 to 1013 M for MUV ∼ −19 to −23.5 mag. Halo mass is also observed to increase from 109.8 to 1012 M for dust-corrected UV star formation rates from ∼0.6 to 10 M yr−1 and continues to increase up to 1013 M in halo mass, where the majority of those sources are active galactic nuclei. 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.

galaxies: evolution; galaxies: haloes; galaxies: high-redshift; galaxies: star formation; cosmology: observations; large-scale structure of Universe; Astrophysics - Astrophysics of Galaxies

Monthly Notices of the Royal Astronomical Society
Volume 489, Issue 1, Page 555
2019 October

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Instituto de Astrofísica e Ciências do Espaço Universidade do Porto Faculdade de Ciências da Universidade de Lisboa
Fundação para a Ciência e a Tecnologia COMPETE 2020 PORTUGAL 2020 União Europeia