2018ApJ...854L...7C

Himiko is one of the most luminous Lyα emitters at z = 6.595. It has three star-forming clumps detected in the rest-frame UV, with a total SFR = 20 M_☉ yr^–1. We report the Atacama Large Millimeter/submillimeter Array (ALMA) detection of the [C II]158 µm line emission in this Galaxy with a significance of 8σ. The total [C II] luminosity (L_[C II]_ = 1.2 x 10⁸ L_☉) is fully consistent with the local L_[C II]_-SFR relation. The ALMA high-angular resolution reveals that the [C II] emission is made of two distinct components. The brightest [C II] clump is extended over 4 kpc and is located on the peak of the Lyα nebula, which is spatially offset by 1 kpc relative to the brightest UV clump. The second [C II] component is spatially unresolved (size <2 kpc) and coincident with one of the three UV clumps. While the latter component is consistent with the local L_[C II]_-SFR relation, the other components are scattered above and below the local relation. We shortly discuss the possible origin of the [C II] components and their relation with the star-forming clumps traced by the UV emission.