Dissecting a 30 kpc galactic outflow at z 1.7

We present the spatially resolved measurements of a cool galactic outflow in the gravitationally lensed galaxy RCS0327 at z approximate to 1.703 using VLT/MUSE IFU observations. We probe the cool outflowing gas, traced by blueshifted Mg ii and Fe ii absorption lines, in 15 distinct regions of the same galaxy in its image-plane. Different physical regions, 5 - 7 kpc apart within the galaxy, drive the outflows at different velocities (V-out similar to -161 to -240 km s(-1)), and mass outflow rates ((M) over dot(out) similar to 183 - 527 M-circle dot yr(-1)). The outflow velocities from different regions of the same galaxy vary by 80 km s(-1), which is comparable to the variation seen in a large sample of star-burst galaxies in the local universe. Using multiply lensed images of RCS0327, we probe the same star-forming region at different spatial scales (0.5-25 kpc(2)), we find that outflow velocities vary between similar to -120 and -242 km s(-1), and the mass outflow rates vary between similar to 37 and 254 M-circle dot yr(-1). The outflow momentum flux in this galaxy is >= 100% of the momentum flux provided by star formation in individual regions, and outflow energy flux is approximate to 10% of the total energy flux provided by star formation. These estimates suggest that the outflow in RCS0327 is energy driven. This work shows the importance of small scale variations of outflow properties due to the variations of local stellar properties of the host galaxy in the context of galaxy evolution.