Outflow, Infall and Protostars in the Star Forming Core W3-SE

TL;DR

This study presents high-resolution observations of molecular lines in the W3-SE star forming region, revealing outflows, infall, and core fragmentation indicative of intermediate to high-mass star formation within a collapsing molecular core.

Contribution

It provides new detailed observational evidence of outflow and infall processes and core fragmentation in W3-SE, advancing understanding of massive star formation mechanisms.

Findings

Detection of a bipolar outflow from SMA-1 in HCN(3-2)

Inverse P-Cygni profile indicating infall in SMA-1

Fragmentation of the core into two pre-stellar cores SMA-1 and SMA-2

Abstract

We report new results on outflow and infall in the star forming cores W3-SE SMA-1 and SMA-2 based on analysis of $\sim2.5\arcsec$ resolution observations of the molecular lines HCN(3-2), HCO$^+$(3-2), N$_2$H$^+$(3-2) and CH$_3$OH(5$_{2,3}-4_{1,3}$) with the Submillimeter Array. A high-velocity bipolar outflow originating from the proto-stellar core SMA-1 was observed in the HCN(3-2) line, with a projected outflow axis in position angle 48$\arcdeg$. The detection of the outflow is confirmed from other molecular lines. An inverse P-Cygni profile in the HCN(3-2) line toward SMA-1 suggests that at least one of the double cores accretes matters from the molecular core. A filamentary structure in the molecular gas surrounds SMA-1 and SMA-2. Based on the SMA observations, our analysis suggests that the double pre-stellar cores SMA-1 and SMA-2 result from fragmentation in the collapsing massive molecular core W3-SE, and it is likely that they are forming intermediate to high-mass stars which will be new members of a star cluster in the W3-SE region.