1999A&A...347...55P

In this paper we investigate the nuclear activity and stellar population in a sample of 27 physical galaxy pairs. Equivalent widths of absorption features are used to characterise the nuclear stellar population according to templates: most galaxies of the sample have important flux contributions from stars younger than 10⁸ years. According to classical diagnostic-diagrams the galaxies in our sample are either classified as HII regions or have emission line ratios near the transition zone between HII regions and LINERs. Based on the observed spectra, only 4 galaxies show LINER properties and 1 nucleus is a Seyfert2. We found that the spectrum of a transition object (38% of the sample) can be described by a combination of an AGN with an HII region. As a result, 20 galaxies of the present sample may host a low-luminosity active nucleus.