We present deep surface photometry of a volume–limited sample of 21 UM emission line galaxies in broadband optical UBVRI and near infra-red ( NIR ) HKs filters .
The sample comprises 19 blue compact galaxies ( BCGs ) and two spirals .
For some targets the exposure times are the deepest to date .
For the BCG UM462 we observe a previously undetected second disk component beyond a surface brightness level of \mu _ { B } = 26 mag arcsec ^ { -2 } .
This is a true low surface brightness component with central surface brightness \mu _ { 0 } = 24.1 mag arcsec ^ { -2 } and scale length h _ { r } = 1.5 kpc .
All BCGs are dwarfs , with M _ { B } \geq - 18 , and very compact , with an average scale length of h _ { r } \sim 1 kpc .
We separate the burst and host populations for each galaxy and compare them to stellar evolutionary models with and without nebular emission contribution .
We also measure the A _ { 180 } asymmetry in all filters and detect a shift from optical to NIR in the average asymmetry of the sample .
This shift seems to be correlated with the morphological class of the BCGs .
Using the color-asymmetry relation , we identify five BCGs in the sample as mergers , which is confirmed by their morphological class .
Though clearly separated from normal galaxies in the concentration–asymmetry parameter space , we find that it is not possible to distinguish luminous starbursting BCGs from the merely star forming low luminosity BCGs .