Comparison of integrated intensities of our DCO⁺ models (contours, 3 and 5σ, σ = 15 mJy beam^-1 km s^-1) to the observations (image, colors show intensities from 3σ). Colors indicate the velocities included in constructing the zeroth moment maps. Clockwise from the upper left, small figures show: 1) decreasing T_low,DCO⁺ and T_high,DCO⁺ by 3 K, 2) raising T_low,DCO⁺ and T_high,DCO⁺ by 4 K, 3) broadening the temperature range from 2 K to 4 K, with χ_DCO⁺ halved to maintain the same total DCO⁺J = 5–4 line flux, 4) reduction of χ_DCO⁺ by a factor of 3, and 5) raising χ_DCO⁺ by a factor of 3.