• DOI:10.1093/mnras/stx245
• Corpus ID: 55214421

A gravitationally boosted MUSE survey for emission-line galaxies at z ≳ 5 behind the massive cluster RCS 0224.

@article{Smit2017AGB,
  title={A gravitationally boosted MUSE survey for emission-line galaxies at z ≳ 5 behind the massive cluster RCS 0224.},
  author={Renske Smit and A Mark Swinbank and Richard J. Massey and Johan Richard and Ian R. Smail and J.-P. Kneib Cea Durham and Icc Durham and crAl and Epfl and Lam},
  journal={Monthly Notices of the Royal Astronomical Society},
  year={2017},
  volume={467},
  pages={3306-3323}
}

• R. Smit, A. M. Swinbank, +7 authors Lam
• Published 27 January 2017
• Physics
• Monthly Notices of the Royal Astronomical Society

We present a Very Large Telescope/Multi Unit Spectroscopic Explorer (MUSE) survey of lensed high-redshift galaxies behind the z = 0.77 cluster RCS 0224−0002. We study the detailed internal properties of a highly magnified (μ ∼ 29) z = 4.88 galaxy seen through the cluster. We detect widespread nebular C iv λλ1548,1551 A emission from this galaxy as well as a bright Lyα halo with a spatially uniform wind and absorption profile across 12 kpc in the image plane. Blueshifted high- and low-ionization interstellar absorption indicate the presence of a high-velocity outflow (Δv ∼ 300 km s− 1) from the galaxy. Unlike similar observations of galaxies at z ∼ 2 − 3, the Lyα emission from the halo emerges close to the systemic velocity – an order of magnitude lower in velocity offset than predicted in ‘shell’-like outflow models. To explain these observations, we favour a model of an outflow with a strong velocity gradient, which changes the effective column density seen by the Lyα photons. We also search for high-redshift Lyα emitters and identify 14 candidates between z = 4.8 − 6.6, including an overdensity at z = 4.88, of which only one has a detected counterpart in Hubble Space Telescope/Advanced Camera for Surveys+Wide Field Camera 3 imaging.