Moment 0 maps of three CO isotopologues in the W5 region. The integrated local standard of rest velocity range is from V_LSR = –50 to –30 km s⁻¹. The first three figures are ¹²CO, ¹³CO, and C¹⁸O moment 0 maps of integrated intensity. The last one is a comparison of the three isotopologues superimposed, where the background color is the ¹²CO intensity, the contour line is the ¹³CO intensity, and the grey areas refer to positions with notable C¹⁸O emission. The yellow stars, black crosses, and small green and red dots in each map mark OB stars, HMYSOs (Lumsden et al. 2013), and blue and red lobes identified as CO outflows by Li et al. (2019), respectively.