HC H II region. Upper panel: ALMA 2019 data: intensity-weighted velocity (color map) of the H30α emission, obtained from averaging the channel maps produced with a natural weighting of the uv -data. The beam (FWHM 0.′′080 × 0.′′062, with PA = 75°) is shown in the lower left corner. The black contours represent the velocity-integrated intensity of the H30α line, showinglevels from 0.26 to 1.3 in steps of 0.13 Jy beam⁻¹ km s⁻¹. The dashedblack rectangle delimits the field of view shown in the lower panel. Lower panel: ALMA 2015, VLA, and Very Long Baseline Interferometry (VLBI) data. The grayscale image represents the VLA A-Array 7 mm continuum observed by Beltrán et al. (2007). The white triangles and yellow squares mark the VLBI positions of the H₂O 22 GHz (Moscadelli et al. 2007) and CH₃OH 6.7 GHz masers (Moscadelli et al. 2018), respectively; the area of the symbol is proportional to the logarithm of the maser intensity. The white arrows show the proper motions of the H₂O masers, which were first reported and analyzed in Moscadelli et al. (2007). The colored dots give the channel peak positions of the H30α line emissionobtained by Moscadelli et al. (2018) from ALMA data with 0.′′2 resolution; the colors denote the V_LSR as indicated to the right of the plot. The dashed black line marks the axis of the spatial distribution of the H30α peaks.