Results of 168 GHz observations towards NGC 1377. (a) The velocity-integrated line emission maps of H₂S 1_1, 0 − 1_0, 1. Black contours: −70 km s⁻¹ to 70 km s⁻¹ (3, 9, 27, and 36σ, where σ_core = 6.94 × 10⁻³ Jy beam⁻¹ km s⁻¹); blue: −200 km s⁻¹ to −100 km s⁻¹; red: 100 km s⁻¹ to 200 km s⁻¹ (3, 4, and 6σ, where σ_red = 9.35 × 10⁻³ Jy beam⁻¹ km s⁻¹ and σ_blue = 9.38 × 10⁻³ Jy beam⁻¹ km s⁻¹, respectively). The beam size is shown in the bottom left by a grey-filled circle. The blue and red line segments indicate the position angle (PA) of the disc. The PA of the nuclear continuum is 90° (scales of r = 2 pc), and the orientation of the dynamics of the nuclear disk is also close to 90° (Aalto et al. 2020). Aalto et al. (2020) noted that this is different from the 104° found for the major axis on larger scales of r = 10 pc (Aalto et al. 2016). The direction of the molecular outflows detected in CO 3−2 (PA ∼ 11°, Fig. 4, Aalto et al. 2016) is indicated with a black dotted line. (b) The continuum emission at 168 GHz is shown in greyscale and contours (3, 9, 15, and 17σ, where σ_cont = 1.1 × 10⁻⁵ Jy beam⁻¹). (c) Spectrum in the unit of the flux density within the emitting region (over 3σ in moment-0 image) against the line velocity offset at the systemic velocity. The black histogram shows the observation result. The red dotted line indicates the 1σ rms level. The black dashed line shows the narrow line component, the dotted line indicates the broad line component, and the solid line shows two components combined. (d) Spectrum in units of the mean brightness at the peak intensity pixel against the line velocity.