The SAMI Galaxy Survey: the discovery of a luminous, low-metallicity H II complex in the dwarf galaxy GAMA J141103.98-003242.3

We present the discovery of a luminous unresolved H ii complex on the edge of dwarf galaxy GAMA J141103.98−003242.3 using data from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) Galaxy Survey. This dwarf galaxy is situated at a distance of ∼100 Mpc and contains an unresolved region of H ii emission that contributes ∼70 per cent of the galaxy's Hα luminosity, located at the top end of established H ii region luminosity functions. For the H ii complex, we measure a star formation rate of 0.147 ± 0.041 M⊙ yr−1and a metallicity of 12+log(O/H) = 8.01 ± 0.05 that is lower than the rest of the galaxy by ∼0.2 dex. Data from the H i Parkes All-Sky Survey (HIPASS) indicate the likely presence of neutral hydrogen in the galaxy to potentially fuel ongoing and future star-forming events. We discuss various triggering mechanisms for the intense star formation activity of this H ii complex, where the kinematics of the ionized gas are well described by a rotating disc and do not show any features indicative of interactions. We show that SAMI is an ideal instrument to identify similar systems to GAMA J141103.98−003242.3, and the SAMI Galaxy Survey is likely to find many more of these systems to aid in the understanding of their formation and evolution.