[3] Moreover, it belongs to the ultraluminous galaxy classification, because according to IRAS, its luminosity range Lir = 1012-1013 L⊙ is found to be approximated by the power law of Φ(L) ~ L-2.35[Mpc-3 mag-1].

[7] Evidence showed both galaxies have orbited each other several times before merging with each other; signs left included distinct loops of glowing gas around the quasar's host.

[8] Apart from the loop of gas, IRAS 13218+0552 has a tidal tail feature and possibly binary nucleus with its separation smaller than 1 kpc.

[12] This might be caused by OHM emission being pumped by infrared radiation from the galaxy's environment and also amplification of an intense radio continuum background.

Through the observation, IRAS 13218+0552 has an OH spectrum showing two prominent broad emission peaks, having a separation of 490 km s−1 in its rest frame, suggesting it is associated with multiple nuclei.