Evolution of the bar pattern speed with redshift

In a recent published study we have analysed the evolution of the bar pattern speed with redshift using morphological measurements of a sample of low-inclination ringed galaxies from the SDSS and the COSMOS survey. In this paper we summarise the results obtained in that work. The sample covers a redshift range 0 < z < 0.8. We have obtained morphological ratios between the deprojected outer ring radius (Rring) and the bar size (Rbar). This quantity is related to the parameter R = RCR/Rbar used for classifiying bars in slow and fast rotators, and allows us to investigate possible differences with redshift. We do not see any change of the R parameter with redshift. These results are compatible with most of the sample (∼ 70%) being fast-rotators and with no evolution of either the pattern speed or the bar size with redshift.