Hierarchical triple star systems towards the Galactic Bulge through OGLE's eye.

We report the result of eclipse timing variation (ETV) analyses of OGLE-IV eclipsing binaries (EBs). We have identified around 1000 potential triple (or multiple) system candidates and, in addition, we determined the orbital parameters and we carried out statistical analyses of the properties of the candidates. We found that (i) the distribution of the outer eccentricity has a maximum around e(2) = 0.3; (ii) in most cases the estimated outer mass ratio is lower than q(2) similar to 0.5. Besides, we also present some systems that deserve special attention.