Apparent core position as a function of frequency. Circles represent data from this research. The measurement at 8 GHz (square) was taken from Pushkarev et al. (2012) and was not used in the fit. The blue curve indicates the best fit of the form r = aν^−1/k_r + b using 227 GHz as the reference frequency. The orange curve represents the fit adopting the power law index k_r = 1. The error bars include component position uncertainty as well as interpolation uncertainty at 15 and 43 GHz. R_{227 → BH} is the angular distance between the 227 GHz core and the central BH.