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Discovery of a double ring in the dwarf galaxy Mrk409

A. Gil de Paz·B. F. Madore·K. Noeske·L. M. Cairos·P. Papaderos·S. A. Silich
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Abstract

We report the discovery of a double ring of emission-line regions around the nucleus of the Blue Compact Dwarf (BCD) galaxy Mrk409 as seen by deep, ground-based Halpha images. Echelle spectroscopy obtained at Magellan-I with MIKE shows the presence of ionized gas flowing out of the galaxy from a very massive (>7E6 Msun) nuclear starburst with projected expansion velocities of \~50 km/s. Different scenarios for the formation of these rings are discussed. While the innermost, nuclear ring is most probably formed by the interaction of a starburst-driven shock with the surrounding interstellar medium, the origin of the outer ring is less clear.

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A. Gil de Paz, B. F. Madore, K. Noeske, L. M. Cairos, P. Papaderos, S. A. Silich. 2003-09-05. Discovery of a double ring in the dwarf galaxy Mrk409. https://doi.org/10.1086/379601

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