SBPs of Arp 220 computed from simulated V, I, and H images (from top to bottom) in the range 0 ≤ z ≤ 2.6. The central part of the galaxy suffers with increasing redshift a strong dimming in the optical (by ∼6 V mag at z = 1.6) whereas the effect is modest in H (∼0.7 mag at z = 1.6 and ∼1.6 mag at z = 2.6). It can be appreciated that, as the optical SED moves at a higher z into the NIR, the H surface brightness of the less attenuated periphery of the ULIRG gets slightly enhanced, in agreement with the evidence from Fig. 2.