Rest-frame UV and [C II] line maps of the galaxy COS2987 and its surroundings. Left: HST F160W-band image in the background shows the rest-UV emission in a 1.3″ × 1.3″ region around the galaxy. The [C II] integrated map (moment-0) is overlaid as black contours shown at 2-, 4- and 6-σ, where σ is the rms noise level of the moment-0 map. The region containing the foreground galaxy identified by Laporte et al. (2017) is highlighted by the purple line. Middle: zoom-out version of the [C II] moment-0 map toward COS2987 (6″ × 6″). The region shown in the left panel is represented by the dashed white line. We marked the locations of the central source (C), north-east emission (N1), north-west arm (N2), west emission (W1), and south-west emission (W2). The black contours represent the integrated [C II] line emission at 2-, 3-, 4-, 5-, and 6-σ levels and the dashed white contour represents the -2-σ level. The white star corresponds to a galaxy observed in the F160W-band map at z_phot = 1.73 (Laigle et al. 2016). Right: [C II] line integrated map tapered to a 1″ beam size, showing the same region as in the central panel. The black contours represent the 2-, 4-, 6-, 8-, and 10-σ levels and the dashed white contour represents the -2-σ level.