Spectroscopically and spatially resolved optical line emission in the Superantennae (IRAS 19254-7245)
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Date
2009
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Abstract
We present Visible Multi-Object Spectrograph integral-field spectroscopic observations of the ultraluminous infrared galaxy (ULIRG) pair IRAS 19254-7245 (the Superantennae). We resolveH alpha, [N II], [O I] and [S II] 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 less than or similar to 10 per cent of the 24 mu m flux density originates from star formation, implying that most of the 24 mu m emission originates from the active galactic nuclei in the southern nucleus. We also measure a gas consumption time of similar to 1 Gyr, which is consistent with other measurements of ULIRGs.
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galaxies: active, galaxies: individual: IRAS 19254-7245, galaxies: ISM, galaxies: starburst, infrared: galaxies