The faint outskirts of the blue compact galaxy Haro 11: is there a red excess?


E-mail: (GM); (EZ); (GÖ); (NB); (TP)


Previous studies of the low surface brightness host of the blue compact galaxy (BCG) Haro 11 have suggested an abnormally red colour of VK= 4.2 ± 0.8 for the host galaxy. This colour is inconsistent with any normal stellar population over a wide range of stellar metallicities (Z= 0.0010.02). Similar though less extreme host colours have been measured for other BCGs and may be reconciled with population synthesis models, provided that the stellar metallicity of the host is higher than that of the ionized gas in the central starburst. We present the deepest V- and K-band observations to date of Haro 11 and derive a new VK colour for the host galaxy. Our new data suggest a far less extreme colour of VK= 2.3 ± 0.2, which is perfectly consistent with the expectations for an old host galaxy with the same metallicty as that derived from nebular emission lines in the star-forming centre.