Infall and outflow detections in a massive core JCMT 18354-0649S

TL;DR

This study uses high-resolution submillimeter observations to detect and analyze infall and outflow activities in a massive dense core, revealing detailed kinematic processes and molecular tracers involved.

Contribution

It provides new high-resolution imaging and analysis of infall and outflow signatures in a massive core, highlighting the role of HCN as a tracer for both processes.

Findings

Infall rate estimated at 2.0×10^{-3} M_sun/yr.

Detection of outflow with three lobes and total mass of 12 M_sun.

HNC molecules trace both inflow and outflow activities.

Abstract

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 $2.0\times10^{-3} M_{\odot}\cdot$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.