Mapping UV properties throughout the cosmic horseshoe: Lessons from VLT-MUSE

20 Apr 2018

We present the first spatially-resolved rest-frame UV study of the gravitationally lensed galaxy, the 'Cosmic Horseshoe' (J1148+1930) at z=2.38. Our gravitational lens model shows that the system is made up of four star-forming regions, each ~4-8 kpc^2 in size, from which we extract four spatially exclusive regional spectra. We study the interstellar and wind absorption lines, along with CIII] doublet emission lines, in each region to investigate any variation in emission/absorption line properties. The mapped CIII] emission shows distinct kinematical structure, with velocity offsets of ~+/-50 km/s between regions suggestive of a merging system, and a variation in equivalent width that indicates a change in ionisation parameter and/or metallicity between the regions. Absorption line velocities reveal a range of outflow strengths, with gas outflowing between -200