Left panel: map of the 218.9 GHz or 1.37 mm continuum emission observed with the SMA. Contours are –5, 5, 6, 8, 10, 12, 16 and 20 × rms noise = 2.5 mJy beam^-1. Greyscale: –2 to 50 mJy beam^-1. The synthesised beam is shown in the bottom left corner: 4.3′′ × 2.9′′, PA = –1.1°. Right panel: map of the 230.9 GHz or 1.30 mm continuum emission observed with the SMA. The contours and stretch are the same as in the left panel. The synthesised beam is shown in the bottom left corner: 4.3′′ × 2.7′′, PA = 4.0°. In both panels 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 to 6 from Rodríguez & Zapata (2013).