Lyman continuum leaking galaxies- Search strategies and local candidates?

Context. Star-forming dwarf galaxies leaking Lyman-continuum (LyC) radiation may have played an important role in the reionization of the Universe. Local galaxies exhibiting LyC leakage could shed light on the escape mechanisms, but so far only two such cases have been identified. Here, we argue that this meager harvest may be caused by unsuitable selection criteria, one of which is a high equivalent width in Hα emission. Such a criterion will guarantee a high production of LyC photons but also indicates a high column density in the neutral gas, effectively ruling out LyC escape. Aims. We want to investigate whether the lack of local LyC emitters can be caused in part by biased selection criteria, and we present a novel method of selecting targets with high escape fractions. By applying these criteria, we assemble a sample of observation targets to study their basic properties. Methods. We introduce a new selection strategy where the potential LyC leakers are selected by their blue colours and weak emission lines. We also take a closer look at the properties of 8 LyC leaking candidates at z ∼ 0.03, selected from the Sloan Digital Sky Survey (SDSS) which we observe with ESO/NTT in broadband B and Hα. Results. We find that 7 of the 8 target galaxies are involved in interaction with neighbours or show signs of mergers. In 7 cases the young stellar population is clearly displaced relative to the main body of these galaxies. In about half of our targets the absorption spectra show young post-starburst signatures. The scale lengths in Hα are typically 30 % smaller than those of the stellar continua