(a) TeV gamma-ray excess map of RX J1713.7−3946 in equational coordinates obtained by H.E.S.S. (H.E.S.S. Collaboration et al. 2018). Superposed contours indicate the ISM proton column density (Fukui et al. 2012). The contour levels are 6, 7, 8, 10, 12, 14, 16, 18, 20, and 22 × 10²¹ cm⁻². Green rectangles represents the ALMA observed area (small rectangle) and to be presented area in Figure 1(b). The positions of CO peaks C, D, and L are shown. (b) ALMA CO map toward the northwest of RX J1713.7−3946. Superposed contours indicate the X-ray intensity obtained with Chandra (Uchiyama et al. 2007). The lowest contour and contour intervals are 9.5 × 10⁻⁸ and 9.5 × 10⁻⁹ photons cm⁻² s⁻¹ pixel⁻¹, respectively. The colored image in the top left indicates Chandra X-ray map in the same region as shown in Figure 1(b).