A study of a tidally interacting BCD pair, ESO 435-IG20 and ESO 435-IG16

Blue Compact Dwarf galaxies (BCDs) are systems that recently have experienced the burst of star formation. As one of the causes for active star formation in BCDs, tidal interaction (fly-by or merger) has been suggested. A pair of BCDs, ESO 435-IG20 and ESO 435-IG16 are separated by only ~80 kpc in projection at a similar redshift (at a ~9 Mpc distance), and hence suspected to be a good example of such case. Intergalactic atomic hydrogen gas found in HIPASS survey is also suggestive of this hypothesis. In this study, we probe the HI morphology and kinematics of this BCD pair using ATCA HI data to study detailed interaction history. We investigate various star formation tracers of the pair to study how responsible tidal interaction is for triggering star formation in these galaxies.