Major mergers with small galaxies - the discovery of a Magellanic-type galaxy at z=0.12

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We report on the serendipitous discovery of a star-forming galaxy at redshift z=0.116 with morphological features that indicate an ongoing merger. This object exhibits two clearly separated components with significantly different colors, plus a possible tidal stream. Follow-up spectroscopy of the bluer component revealed a low star-forming activity of 0.09 M/year and a high metallicity of 12+log(O/H)=8.6. Based on comparison with mass-star-formation-rate and mass-metallicity relations, and on fitting of spectral energy distributions, we obtain a stellar mass of 3x10⁹ M, which renders this object comparable to the Large Magellanic Cloud (LMC). Thus our finding provides a further piece of evidence of a major merger already acting on small, dwarf galaxy-like scales.