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Appendix A: Notes on individual objects

• HRS2. Our photometry in the SDSS bands may be affected by the presence of a bright star  ~1 arcmin south-west from the target.

• HRS3 & HRS4. Interacting system (Arp 94). Photometry is uncertain due to the overlap between the two objects.

• HRS20. Interacting system (Arp 270). Photometry is uncertain due to the overlap with the companion galaxy.

• HRS42. The point spread function (PSF) of the NUV image is significantly asymmetric and elongated towards North-West. However, this does not affect our integrated photometry and should not significantly influence the estimate of the structural parameters.

• HRS55. The i-band frame could not be used due to the presence of large artifacts created by a nearby foreground bright star.

• HRS60. The i-band photometry is mildly affected by the presence of a satellite track.

• HRS68. The effective radius for this object is significantly smaller than the spatial resolution adopted in this analysis (~6 arcsec). Thus, no effective radius and surface brightness are provided.

• HRS74. The PSF of the NUV image is significantly asymmetric and elongated towards North-East. However, this does not affect our integrated photometry and should not significantly influence the estimate of the structural parameters.

• HRS81. The GALEX images suggest the presence of very low surface brightness loops/tidal features associated to this object, not clearly visible in SDSS. However, the data currently available are not deep enough to determine if these features are real.

• HRS105. This galaxy has an extended UV ring, with ellipticity and position angle (0.5, +34 deg) significantly different from the ones determined from the i-band images (see also Cortese & Hughes 2009; Bettoni et al. 2010). However, the integrated magnitudes do not significantly change if these values are used for the profile fitting.

• HRS177. The GALEX NUV image suggests the presence of a tail of star-forming knots departing from the galaxy towards the north (see also Arrigoni Battaia et al. 2012).

• HRS202. This galaxy has a typical FUV surface brightness fainter than 28 mag arcsec^-2, making impossible to estimate its isophotal radius.

• HRS211. The galaxy center is saturated in the i-band, affecting our photometry.

• HRS213. This edge-on galaxy has a significant bulge component in the optical, which is not visible in the GALEX images. Thus the ellipticity adopted here is not a fair representation of the UV light distribution and could affect our estimate of the UV structural parameters.

• HRS215 & HRS216. Interacting system. Photometry is uncertain due to the overlap between the two objects.

• HRS244 & HRS245. Interacting system. Photometry is uncertain due to the overlap between the two objects.

• HRS265. The PSF of the NUV image is significantly asymmetric and elongated towards North-West. However, this does not affect our integrated photometry and should not significantly influence the estimate of the structural parameters.

© ESO, 2012