Faint LAEs near z>4.7 CIV absorbers revealed by MUSE

Abstract

We present the results from the search for Lyman Alpha emitters (LAEs) in the proximity of 11 CIV absorption systems at $z>4.7$ in the spectrum of the QSO J1030+0524, using data from MUSE. We have found multiple LAE candidates close to four CIV systems at $z_{CIV}=4.94$-5.74 with log${}_{10}$(N CIV[cm${}^{-2}$])$>\mathrm{13.5.}$ At z = 5-6, CIV systems with W0(CIV) $>0.2$ à seem more likely to have galaxies with Ly$\hat{I}\pm$ emission within $\ddot{I}<200$ proper kpc (4/5 cases), than the CIV systems with W0(CIV)$<0.2$ à (0/6 cases). The impact parameter of LAE-CIV systems with equivalent widths W0(CIV)$>0.5$ à is in the range 11 $<\ddot{I}<$ 200 proper kpc (pkpc). Furthermore, all candidates are in the luminosity range 0.18-1.15 L*$(Ly\hat{I}\pm ,z=5.7)$ indicating that the environment of CIV systems within 200 pkpc is populated by the faint end of the Ly$\hat{I}\pm$ luminosity function. We report a 0.28 L*$(Ly\hat{I}\pm )$ galaxy at a separation of $\ddot{I}=10$ pkpc from a strong CIV absorption (log10(NCIV[cm${}^{-2}$]) = 14.52) at $z_{CIV}=5.72419$. The prevalence of sub-L*(Ly$\hat{I}\pm$) galaxies in the proximity of z $>4.9$ CIV systems suggest that the absorbing material is rather young, likely ejected in the recent past of the galaxies at these redshifts. 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.

21 pages, 23 figures, 3 tables. Submitted to MNRAS