ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
tokens: galaxies (Fig. 11 , upper right panel). Due to the relatively small range in redshift across the sample, this difference is not likely due to evolution. In the case of inner (r) and outer (R) rings, a small dependency is found (a p -value of 5.46 per cent). Both galaxies with outer and inner rings in the isolated sample are on average found at slightly larger distances than those without these features. We repeated the tests above to look for bias due to galaxy inclination (Fig. 12 ), but in all cases we found no apparent dependency, consistent with what we illustrated in Figs 6 – 8 . However, whether or not a spiral galaxy is identified as either grand design or flocculent is clearly dependent on both distance and inclination. This is illustrated in the top two panels of Fig. 16 . The sample grand design spirals seem to be more easily identified at lower inclinations and on average are more distant than the sample flocculent spirals. The dependence on inclination may not be unexpected because spiral arm contrast is lower the more inclined the disc galaxy. The dependence on distance could reflect the fact that grand design spirals tend to occur in more luminous systems than do flocculent spirals, and hence can be recognized to greater distances (Section 7). 8.2 Morphological features and isolation Using the same approach as above, we analysed whether the distributions of two environmental parameters: η k and Q Kar, p (Verley et al. 2007b ), were altered by restricting to subsamples of specific morphological features. η k is the logarithm of the local volume density of neighbouring galaxies, based on the projected separation to the k th neighbour and the distance estimate of the galaxy in question (Verley et al. 2007b ). Only neighbours that have diameters that are 0.25–4 times that of the target galaxy are considered, as larger (smaller) galaxies are assumed to be foreground (background) objects. However, this does leave open the possibility that some low-mass dwarf companions might be neglected. Typically k = 5, but in some cases the available optical field is too small to identify five neighbours and a lower value of k is used instead. Q Kar, p is a logarithmic and dimensionless measurement of the ratio of a galaxy’s internal gravitational binding force to external tidal forces, which assumes that galaxy diameter is a proxy for total mass (Verley et al. 2007b ). For CIG galaxies the mean values of η k and Q Kar, p are 1.4 and −2.7, and their standard deviations are 0.6 and 0.7, respectively. Figs 13 and 14 show the comparative histograms for stage, family, and inner and outer varieties versus η k and Q Kar, p ; the comparisons for AC are shown in the middle two panels of Fig. 16 . We find no dependency on the isolation parameters regarding the detection of inner or outer rings and bars, which could either be a sign of the minimal impact of the environment on the generation of these features, or could be indicating that the scatter in