Revealing the Nature of a Ly? Halo in a Strongly Lensed Interacting System at z = 2.92

Abstract Spatially extended halos of H i Ly ? emission are now ubiquitously found around high-redshift star-forming galaxies. But our understanding the nature and powering mechanisms these is still hampered by complex radiative transfer effects line limited angular resolution. In this paper, we present resolved Multi Unit Spectroscopic Explorer (MUSE) observations SGAS J122651.3+215220, a strongly lensed pair L * galaxies at z = 2.92 embedded in halo (6.2 ± 1.3) × 10 42 erg s ?1 . Globally, system shows profile that markedly asymmetric redshifted, but its width peak shift vary significantly across halo. By fitting spatially binned spectra with collection galactic wind models, infer mean outflow expansion velocity ?211 km , higher values preferentially on both sides system’s major axis. The validated blueshift low-ionization metal absorption lines central We also identify faint ( M 1500 ? ?16.7) companion detected continuum, whose properties agreement predicted population satellite contribute to emission. Finally, briefly discuss impact interaction between possibility situ fluorescent production.