Figure 8 Global H i emission profile of NGC 6907 and 6908 Figure 8 Global H i emission profile of NGC 6907 and 6908. The bottom dotted lines limit the noise level while the top dotted line indicates the maximum emission h. Inside the distribution, two horizontal dashed lines are used to mark the H i line-widths estimated at 20 per cent (w<sub>20</sub>) and at 50 per cent (w<sub>50</sub>) of the peak intensities; v is the central weighted mean velocity distribution. From: H i aperture synthesis and optical observations of the pair of galaxies NGC 6907 and 6908 Mon Not R Astron Soc. 2008;386(2):963-972. doi:10.1111/j.1365-2966.2008.13079.x Mon Not R Astron Soc | © 2008 The Authors. Journal compilation © 2008 RAS 1