Vicinity of the first site of maser emission and the central region of the complex. The OH maser position isindicated by a red plus symbol. The orange arrow indicates the best candidate exciting star proposed by Vig et al. (2007). The red contours indicate the column density (levels of 1.0, 1.5, and 2.0 × 10²³ cm⁻²). Panel a: green contours indicate the NH₃ emission (Longmore et al. 2007, their Fig. 11); the underlying grey image is the Spitzer 8.0 μm image. Panel b: blue contours now indicate the radio-continuum emission at 24 GHz (Longmore et al. 2007). Panel c: composite JHK_s colour image (VISTA images) showing the dark absorption features and the exciting star proposed by Vig et al. (2007). A zoomed view of maser site at 2.2 μm (VISTA) and 4.5 μm (Spitzer) is shown in the bottom-left panel.