Comparison plot of the absorption column density values derived from the atomic and molecular gas and from the X-rays using XMM-Newton observations. The X-ray columns derived toward the rims of the RX J0852.0−4622 SNR, PSR J0855 − 4644 and the PWN are represented by black circles, a blue square, and a green square. The errors on the X-ray N_H are 1σ error bars. The label over each point corresponds to regions where the values were measured as defined in Fig. 7.