Previous observations have revealed an accretion disk and outflow motion in high-mass star-forming region G192.16-3.84. While collapse have not been reported before. We present here molecular line and continuum observations toward massive core G192.16-3.84 with the Submillimeter Array. C^18O(2-1) and HCO^+(3-2) lines show pronounced blue profiles, indicating gas infalling in this region. This is the first time that the infall motion has been reported in G192.16-3.84 core. Two-layer model

more »

... gave 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)×10^-3 and (6.6±2.1)×10^-3 M_ yr^-1 for C^18O(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 to form a massive star.