Dust and infrared imaging of polar ring galaxies

We have derived surface photometry for a sample of five polar ring (PR) galaxies in the optical (B and R bands) and in the near-IR (K band). Our preliminary results show that the morphology of these objects is heavily perturbed by dart, which sometimes completely hides the real distribution of the older stellar population. The analysis of the colour profiles and of the integrated colours of the host galaxy and polar ring in these systems indicates that (1) the ring and the central galaxy appear to have different stellar populations, which supports the accretion /merging scenario for these objects, and (2) although the host galaxies have an early-type morphology, their integrated colours are close to those of spirals, with a strong blueward colour gradient from the centre outward.