Spectra from NH₃ (9,6) transition lines. Left: top to bottom: time sequence of NH₃ (9,6) profiles observed toward Cep A with the Effelsberg 100-meter telescope (after subtracting a first-order polynomial baseline). A JVLA spectrum is interspersed. The systemic velocity from CO and HCO⁺ lines is indicated by a dashed blue line. The two dashed red lines at LSR velocities, V_LSR, of −0.90 km s⁻¹ and −0.28 km s⁻¹ indicate the central velocities of the two major components. Right: NH₃ (9,6) spectrafrom G34.26+0.15. The systemic velocity from C¹⁷O is indicated by a dashed blue line. The three dashed red lines at V_LSR = 54.1 km s⁻¹, 55.8 km s⁻¹, and 62.5 km s⁻¹ show the central velocities of the main ammonia emission components.