Deep multiband surface photometry on a sample of 24 blue compact galaxies

II. A volume-limited sample of 21 emission line galaxies^⋆

¹ Stockholm Observatory, Department of Astronomy, Stockholm University, 10691 Stockholm, Sweden
e-mail: genoveva@astro.su.se
² Oskar Klein Centre for Cosmoparticle Physics, Department of Astronomy, Stockholm University, 10691 Stockholm, Sweden
³ Division of Astronomy & Space Physics, Uppsala University, 75120 Uppsala, Sweden
⁴ Instituto Astrofisica Andalucia (IAA), CSIC, 18008 Granada, Spain
⁵ Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, 43994 Onsala, Sweden
⁶ UPMC – CNRS, UMR 7095, Institut d’Astrophysique de Paris, 75014 Paris, France

Received: 2 October 2012
Accepted: 26 April 2013

Abstract

Aims. We present deep surface photometry of a volume-limited sample of 21 UM emission line galaxies in broadband optical UBVRI and near infrared (NIR) HKs filters. The sample comprises 19 blue compact galaxies (BCGs) and two spirals.

Methods. We separated the burst and host populations for each galaxy and compared them to stellar evolutionary models with and without nebular emission contribution. We measured and analyzed the A₁₈₀ asymmetry in all filters, the concentration index C, the scale length, and the central surface brightness of the host galaxy.

Results. A shift in the average A₁₈₀ asymmetry is detected from optical to NIR. This shift seems 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.