Koch, Andreas and Frank, Matthias J. and Pasquali, Anna and Rich, R. Michael and Rabitz, Andreas (2015) Major mergers with small galaxies : the discovery of a Magellanic-type galaxy at z=0.12. The Astrophysical Journal, 815 (2): 105. ISSN 0004-637X
1511.01499v1.pdf - Accepted Version
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Abstract
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⊙ yr−1 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 3 × 109 M⊙, which renders this object comparable to the Large Magellanic Cloud. Thus our finding provides a further piece of evidence of a major merger already acting on small, dwarf-galaxy-like scales.