Emission signatures from galactic winds provide an opportunity to directly map the outflowing gas , but this is traditionally challenging because of the low surface brightness .
Using very deep observations ( 27 hours ) of the Hubble Deep Field South with the Multi Unit Spectroscopic Explorer ( MUSE ) instrument , we identify signatures of an outflow in both emission and absorption from a spatially resolved galaxy at z = 1.29 with a stellar mass M _ { \star } = 8 \times 10 ^ { 9 } M _ { \odot } , star formation rate \text { SFR } = 77 ^ { +40 } _ { -25 } M _ { \odot } yr ^ { -1 } , and star formation rate surface brightness \Sigma _ { SFR } = 1.6 M _ { \odot } kpc ^ { -2 } within the [ O ii ] \lambda \lambda 3727 , 3729 half-light radius R _ { 1 / 2 , [ \hbox { { O } \kern 1.0 pt { \sc ii } } ] } = 2.76 \pm 0.17 kpc .
From a component of the strong resonant Mg II and Fe II absorptions at -350 km s ^ { -1 } , we infer a mass outflow rate that is comparable to the star formation rate .
We detect non-resonant Fe II * emission , at \lambda 2626 , \lambda 2612 , \lambda 2396 , and \lambda 2365 , at 1.2 - 2.4 - 1.5 - 2.7 \times 10 ^ { -18 } egs s ^ { -1 } cm ^ { -2 } respectively .
These flux ratios are consistent with the expectations for optically thick gas .
By combining the four non-resonant Fe II * emission lines , we spatially map the Fe II * emission from an individual galaxy for the first time .
The Fe II * emission has an elliptical morphology that is roughly aligned with the galaxy minor kinematic axis , and its integrated half-light radius , R _ { 1 / 2 , { Fe \textsc { II } } * } = 4.1 \pm 0.4 kpc , is 50 % larger than the stellar continuum ( R _ { 1 / 2 , \star } \simeq 2.34 \pm 0.17 ) or the [ O ii ] nebular line .
Moreover , the Fe II * emission shows a blue wing extending up to -400 km s ^ { -1 } , which is more pronounced along the galaxy minor kinematic axis and reveals a C-shaped pattern in a p - v diagram along that axis .
These features are consistent with a bi-conical outflow .