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$^{-2}$])$ > 13.5.$ At z = 5-6, CIV systems with W0(CIV) $> 0.2$ {\AA} seem more likely to have galaxies with Ly${\alpha}$ emission within $\rho < 200$ proper kpc (4/5 cases), than the CIV systems with W0(CIV)$ < 0.2$ {\AA} (0/6 cases). The impact parameter of LAE-CIV systems with equivalent widths W0(CIV)$ > 0.5 $ {\AA} is in the range 11 $ < \rho <$ 200 proper kpc (pkpc). Furthermore, all candidates are in the luminosity range 0.18-1.15 L*$(Ly{ \alpha }, z = 5.7)$ indicating that the environment of CIV systems within 200 pkpc is populated by the faint end of the Ly${\alpha}$ luminosity function. We report a 0.28 L*$(Ly{\alpha})$ galaxy at a separation of $\rho = 10$ pkpc from a strong CIV absorption (log10(NCIV[cm$^{-2}$]) = 14.52) at $z_{CIV} = 5.72419$. The prevalence of sub-L*(Ly$\alpha$) 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.