%0 Generic %1 smit2017gravitationallyboosted %A Smit, Renske %A Swinbank, A. M. %A Massey, Richard %A Richard, Johan %A Smail, Ian %A Kneib, J. P. %D 2017 %K Lya galaxies halos high-z %T A gravitationally-boosted MUSE survey for emission-line galaxies at z>~5 behind the massive cluster RCS 0224 %U http://arxiv.org/abs/1701.08160 %X We present a VLT/MUSE survey of lensed high-redshift galaxies behind the z=0.77 cluster RCS0224-0002. We study the detailed internal properties of a highly magnified (\mu~29) z=4.88 galaxy seen through the cluster. We detect wide-spread nebular CIVłambdałambda1548,1551\AA emission from this galaxy as well as a bright Ly\alpha halo with a spatially-uniform wind and absorption profile across 12 kpc in the image plane. Blueshifted high- and low-ionisation interstellar absorption indicate the presence of a high-velocity outflow (\Deltav~300 km/s) from the galaxy. Unlike similar observations of galaxies at z=2-3, the Ly\alpha 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 Ly\alpha photons. We also search for high-redshift Ly\alpha emitters and identify 14 candidates between z=4.8-6.6, including an over-density at z=4.88, of which only one has a detected counterpart in HST/ACS+WFC3 imaging.

@misc{smit2017gravitationallyboosted, abstract = {We present a VLT/MUSE survey of lensed high-redshift galaxies behind the z=0.77 cluster RCS0224-0002. We study the detailed internal properties of a highly magnified ({\mu}~29) z=4.88 galaxy seen through the cluster. We detect wide-spread nebular CIV{\lambda}{\lambda}1548,1551{\AA} emission from this galaxy as well as a bright Ly{\alpha} halo with a spatially-uniform wind and absorption profile across 12 kpc in the image plane. Blueshifted high- and low-ionisation interstellar absorption indicate the presence of a high-velocity outflow ({\Delta}v~300 km/s) from the galaxy. Unlike similar observations of galaxies at z=2-3, the Ly{\alpha} 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 Ly{\alpha} photons. We also search for high-redshift Ly{\alpha} emitters and identify 14 candidates between z=4.8-6.6, including an over-density at z=4.88, of which only one has a detected counterpart in HST/ACS+WFC3 imaging.}, added-at = {2017-01-31T09:52:29.000+0100}, author = {Smit, Renske and Swinbank, A. M. and Massey, Richard and Richard, Johan and Smail, Ian and Kneib, J. P.}, biburl = {https://www.bibsonomy.org/bibtex/2bfe5a265d40ec1be2127ba251fdb48f3/miki}, description = {[1701.08160] A gravitationally-boosted MUSE survey for emission-line galaxies at z>~5 behind the massive cluster RCS 0224}, interhash = {64131d13f5afcbbc21963f2d43d78f84}, intrahash = {bfe5a265d40ec1be2127ba251fdb48f3}, keywords = {Lya galaxies halos high-z}, note = {cite arxiv:1701.08160Comment: 21 pages, 16 figures, MNRAS, in press}, timestamp = {2017-01-31T09:52:29.000+0100}, title = {A gravitationally-boosted MUSE survey for emission-line galaxies at z>~5 behind the massive cluster RCS 0224}, url = {http://arxiv.org/abs/1701.08160}, year = 2017 }