We present a high-resolution study of a massive dense core JCMT 18354-0649S with the Submillimeter Array .
The core is mapped with continuum emission at 1.3 mm , and molecular lines including CH _ { 3 } OH ( 5 _ { 23 } – 4 _ { 13 } ) and HCN ( 3–2 ) .
The dust core detected in the compact configuration has a mass of 47 ~ { } M _ { \odot } and a diameter of 2 \arcsec ( 0.06 pc ) , which is further resolved into three condensations with a total mass of 42 ~ { } M _ { \odot } under higher spatial resolution .
The HCN ( 3–2 ) line exhibits asymmetric profile consistent with infall signature .
The infall rate is estimated to be 2.0 \times 10 ^ { -3 } ~ { } M _ { \odot } \cdot yr ^ { -1 } .
The high velocity HCN ( 3-2 ) line wings present an outflow with three lobes .
Their total mass is 12 ~ { } M _ { \odot } and total momentum is 121 ~ { } M _ { \odot } \cdot km s ^ { -1 } , respectively .
Analysis shows that the N-bearing molecules especially HCN can trace both inflow and outflow .