HCO⁺(1 − 0) and H¹³CO⁺(1 − 0) spectra in black and red, respectively, toward the northwestern region A of DR20. The y-axis of the spectra shows the flux densities in units of Jy beam⁻¹. The color-scale in the bottom right panel shows the corresponding HCO⁺ first-moment map, in which the stars mark the positions of the presented spectra. The contours show the HCO⁺(1 − 0) integrated intensity map (from −7 to 3 km s⁻¹) from 5 to 95% of the peak emission in steps of 10%.