Abstract
We carried out near infrared (NIR) imaging of the BCD Haro 2 in J and H bands which confirms that the J-H color is typical of a slightly blue S0 galaxy. The absence of asymmetries in the central NIR light distribution is similar to what is seen in unperturbed early-type galaxies, in spite of being a gas rich galaxy (in both HI and CO), with a high SFR. To better understand this peculiar object we obtained medium-resolution optical spectroscopy, which suggests continuous star formation over the past few ×10^8 yr. This age for the burst is consistent with the observed oxygen abundance and with the nitrogen to oxygen ratio. We reanalyze VLA HI data which, compared with the NIR images and CO(1-0) maps, confirm a major gas accretion event, most likely the result of an interaction with a gas rich companion. Our observations indicate that Haro 2 is likely a dwarf elliptical which suffered a fly-by interaction a few times 10^8 years ago; this resulted in the accretion of a substantial amount of gas and the subsequent triggering of star formation.
