SMA CH₃OH 4(2, 2)–3(1, 2)-E, SO, HNCO and SiO emission. Contours are –5, 5, 8, 12, 16 and 20× the rms noise values for each line given in Table 1, for a spectral resolution of 5 km s^-1. A synthesised beam of 4.3′′ × 2.9′′, PA = 0° is shown in the bottom left corner. The plus sign marks the position of the water maser reported by Lis et al. (1994) and the crosses mark (from north to south, respectively) the positions of the 1.3 cm sources VLA 4 and 5 from Rodríguez & Zapata (2013). The dashed grey contour shows the combined dust continuum emission at a level of 0.024 mJy beam^-1, the lowest solid black contour shown in Fig. 4.