2009MNRAS.399L..29B

We present Visible Multi-Object Spectrograph integral-field spectroscopic observations of the ultraluminous infrared galaxy (ULIRG) pair IRAS 19254-7245 (the Superantennae). We resolve Hα, [Nii], [Oi] and [Sii] emission both spatially and spectroscopically, and separate the emission into multiple velocity components. We identify spectral line emission characteristic of star formation associated with both galaxies, broad spectral line emission from the nucleus of the southern progenitor and potential outflows with shock-excited spectral features near both nuclei. We estimate that ≲10 per cent of the 24 µm flux density originates from star formation, implying that most of the 24 µm emission originates from the active galactic nuclei in the southern nucleus. We also measure a gas consumption time of ∼1 Gyr, which is consistent with other measurements of ULIRGs.