Probability maps in gradient-intercept space for linewidth-size relation (top) and mass-size relation (bottom), assuming a probability of one that the parameters are within the ranges of the plot. The original Larson (1981) fits are denoted by a grey star, and the fits from Fig. 3 are denoted by a blue circle. The 95% confidence intervals are encircled in red, and the 99.7% confidence intervals are presented in grey.