2004ApJ...615L..89S

By obtaining integral field spectra of the interacting galaxy system NGC 6090, we have found a kiloparsec-scale region where active star formation is currently increasing the fraction of heavy elements. Young massive starbursts are occurring in regions offset from the galactic centers, highlighting the present epoch of metal enrichment over the previous ones usually seen at galactic centers. The short timescale of ∼10⁷ yr for the starbursts, inferred from the galactic rotation, provides a strong constraint on the origins of the metallicity/abundance enhancements. While oxygen is considered to originate in supernovae, the observed nitrogen enhancement is likely to be caused by winds/mass loss from massive stars rather than being a product of intermediate-mass stars.