Faint LAEs near z > 4.7 C iv absorbers revealed by MUSE

Abstract

We present the results from the search for Lyman alpha emitters (LAEs) in the proximity of 11 C iv absorption systems at z > 4.7 in the spectrum of the QSO J1030+0524, using data from Multi-Unit Spectroscopic Explorer. We have found multiple LAE candidates close to four C iv systems at z CIV=4.94-5.74 with log 10(N CIV[cm-2]) > 13.5. At z = 5-6, C iv systems with W 0(C IV)> 0.2 Å seem more likely to have galaxies with Ly α emission within ρ < 200 proper kpc (4/5 cases) than the C iv systems with W 0(C IV)< 0.2 Å (0/6 cases). The impact parameter of LAE-C iv systems with equivalent widths W0(C iv) > 0.5 Å is in the range 11\, ≲, ρ, ≲, 200 proper kpc (pkpc). Furthermore, all candidates are in the luminosity range 0.18-1.15 L☆ Lyα(z=5.7), indicating that the environment of C iv systems within 200 pkpc is populated by the faint end of the Ly α luminosity function. We report a 0.28 L∗ Lyα galaxy at a separation of ρ = 11 pkpc from a strong C iv absorption (log 10(N C IV[$cm-2]) = 14.52) at zC IV=5.72419. The prevalence of sub-L∗ Lyα galaxies in the proximity of z > 4.9 C iv systems suggest that the absorbing material is rather young, likely ejected in the recent past of the identified galaxies. The connection between faint LAEs and high-ionization absorption systems reported in this work is potentially a consequence of the role of low-mass galaxies in the early evolution of the circum-galactic and intergalactic media.