The 4.2′′ × 3.7′′ regions centered on HAE229. Top left panel: a composite three-color image made by combining the Y-, H-, and K_s-band color images taken with HAWK-I on the ESO/VLT (see text and Table 2 for details). To show the rest-frame blue and red optical morphology, we show each color component of the composite separately, namely, Y-band (approximately rest-frame U-band, top right), H-band (approximately rest-frame B- or V-band, bottom left) and K_s-band (approximately rest-frame R-band, bottom right). The Y-band image has a morphology similar to that of the F814W image and no offset is detected between the rest-frame UV and rest-frame optical regions. With increasing wavelength, the emission becomes less clumpy, more regular, and a red nucleus is evident. The dynamical center of the CO(1–0) emission corresponds to the highest surface brightness region of the H- and K_s-band images suggesting this region is also the center of mass of the galaxy. The bright galaxy above HAE229 in all panels lies at z_phot ≈ 0.5 (Tanaka et al. 2010).