2019RAA....19...40T

Previous observations have revealed an accretion disk and outflow motion in the high-mass star-forming region G192.16-3.84, but collapse has not been reported before. Here we present molecular line and continuum observations toward the massive core G192.16-3.84 with the Submillimeter Array. C¹⁸O(2-1) and HCO⁺(3-2) lines show pronounced blue profiles, indicating gas infalling in this region. This is the first time that infall motion has been reported in the G192.16-3.84 core. Two-layer model fitting gives infall velocities of 2.0±0.2 and 2.8±0.1 km s^–1. Assuming that the cloud core follows a power-law density profile (ρ ∝ r^1.5), the corresponding mass infall rates are (4.7±1.7)x10^–3 and (6.6±2.1)x10^–3M_☉ yr^–1 for C¹⁸O(2-1) and HCO⁺(3-2), respectively. The derived infall rates are in agreement with the turbulent core model and those in other high-mass star-forming regions, suggesting that high accretion rate is a general requirement for forming a massive star.