The environment and star formation of HII region Sh2-163: a multi-wavelength study

TL;DR

This multi-wavelength study of HII region Sh2-163 reveals interactions with surrounding molecular clouds and evidence of triggered star formation, including active star-forming clumps and a potential massive protostar.

Contribution

First comprehensive multi-wavelength analysis of Sh2-163 demonstrating triggered star formation due to HII region expansion.

Findings

Discovery of two molecular clouds compressed by Sh2-163

Active star formation in molecular clumps, especially A2

Identification of a likely massive protostar near IRAS 23314+6033

Abstract

To investigate the environment of HII region Sh2-163 and search for evidence of triggered star formation in this region, we performed a multi-wavelength study of this HII region. Most of our data were taken from large-scale surveys: 2MASS, CGPS, MSX and SCUBA. We also made CO molecular line observations, using the 13.7-m telescope. The ionized region of Sh2-163 is detected by both the optical and radio continuum observations. Sh2-163 is partially bordered by an arc-like photodissociation region (PDR), which is coincident with the strongest optical and radio emissions, indicating interactions between the HII region and the surrounding interstellar medium. Two molecular clouds were discovered on the border of the PDR. The morphology of these two clouds suggests they are compressed by the expansion of Sh2-163. In cloud A, we found two molecular clumps. And it seems star formation in clump A2 is much more active than in clump A1. In cloud B, we found new outflow activities and massive star(s) are forming inside. Using 2MASS photometry, we tried to search for embedded young stellar object (YSO) candidates in this region. The very good agreement between CO emission, infrared shell and YSOs suggest that it is probably a star formation region triggered by the expansion of Sh2-163.We also found the most likely massive protostar related to IRAS 23314+6033.