Abstract

BRAVO-ALFARO, H.; COZIOL, R.  and  BRINKS, E.. Multifrequency study of the blue compact dwarf haro 2: nir imaging and optical spectroscopy. Rev. mex. astron. astrofis [online]. 2006, vol.42, n.2, pp.261-272. ISSN 0185-1101.

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 H I 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 ×10⁸ yr. This age for the burst is consistent with the observed oxygen abundance and with the nitrogen to oxygen ratio. We reanalyze VLA H I 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 10⁸ years ago; this resulted in the accretion of a substantial amount of gas and the subsequent triggering of star formation.

Keywords : GALAXIES [DWARF]; GALAXIES [INDIVIDUAL (HARO 2)]; GALAXIES [KINEMATICS AND DYNAMICS]; TECHNIQUES [SPECTROSCOPIC].

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