CLASH-VLT: spectroscopic confirmation of a z = 6.11 quintuply lensed galaxy in the Frontier Fields Cluster RXC J2248.7-4431 (Corrigendum)

Abstract

We present VIsible Multi-Object Spectrograph (VIMOS) observations of a z ∼ 6 galaxy quintuply imaged by the Frontier Fields galaxy cluster RXC J2248.7-4431 (z = 0.348). This sub-L * , high-z galaxy has been recently discovered by Monna et al. (2013) using dropout techniques with the 16-band HST photometry acquired as part of the Cluster Lensing And Supernova survey with Hubble (CLASH). Obtained as part of the CLASH-VLT survey, the VIMOS medium-resolution spectra of this source show a very faint continuum between ∼ 8700Å and ∼ 9300Å and a prominent emission line at 8643Å, which can be readily identified with Lyman-α at z = 6.110 ± 0.002. The emission line exhibits an asymmetric profile, with a more pronounced red wing. The rest-frame equivalent width of the line is EW = 79 ± 10 Å, relatively well constrained thanks to the detection of the UV continuum, which is rarely achieved for a sub-L * galaxy at this redshift. After correcting for magnification, the star formation rate (SFR) estimated from the Lyα line is SFR(Lyα) = 11 M ⊙ yr −1 and that estimated from the UV data is SFR(UV) = 3 M ⊙ yr −1 . We estimate that the effective radius of the source is R e 0.4 kpc, which implies a star formation surface mass density Σ S FR > 6 M ⊙ yr −1 kpc −2 and, using the Kennicutt-Schmidt relation, a gas surface mass density Σ gas > 10 3 M ⊙ pc −2 . Our results support the idea that this magnified, distant galaxy is a young and compact object with luminosity 0.4 L * at z = 6, when the Universe was just 1 Gyr old, with a similar amount of mass in gas and stars. In the spirit of the Frontier Fields initiative, we also publish the redshifts of several multiply imaged sources and other background objects, which will help improving the strong-lensing model of this galaxy cluster.

The Kormendy relation of early-type galaxies as a function of wavelength in Abell S1063, MACS J0416.1-2403, and MACS J1149.5+2223

“…Lotz, Lotz et al 2017), aiming at combining the power of HST and Spitzer with the natural gravitational telescope effect of massive highmagnification clusters of galaxies. These datasets allow us, for instance, to test predictions of the ΛCDM model (Annunziatella et al 2017;Sartoris et al 2020), to measure the Hubble constant value (Grillo et al 2018(Grillo et al , 2020, to refine weak and strong lensing models to map the total mass distribution in clusters (Gruen et al 2013;Caminha et al 2016;Bergamini et al 2019;Granata et al 2022) and to serendipitously discover very distant lensed galaxies up to z ∼ 6 (Vanzella et al 2016;Balestra et al 2018).…”