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$^{18}$O(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 fitting gave infall velocities of 2.0$pm$0.2 and 2.8$pm$0.1 km s$^{-1}$. Assuming that the cloud core follows a power-law density profile ($rho$$propto$$r^{1.5}$), the corresponding mass infall rates are (4.7$pm$1.7)$times10^{-3}$ and (6.6$pm$2.1)$times10^{-3}$ M$_{sun}$ yr$^{-1}$ for C$^{18}$O(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.
تحميل البحث