The nature of the compact HII region Sh 2-89 and its stellar content

TL;DR

This study analyzes the structure and stellar content of the compact HII region Sh 2-89 using Spitzer MIR data and spectroscopy, revealing a bipolar morphology, diverse YSOs, and complex ionization features.

Contribution

It provides detailed insights into the morphology, stellar population, and ionization structure of Sh 2-89, combining MIR mapping with spectroscopic analysis for the first time.

Findings

Bipolar structure of Sh 2-89 identified

Presence of Class I and II YSOs within the region

Dominance of PAH emission in MIR flux profiles

Abstract

We present an analysis of the structure and properties of the compact HII region Sh 2-89, and certain of the young stellar objects (YSOs) within this regime, using mid-infrared (MIR) mapping derived from the Spitzer Space Telescope (SST) and visual slit spectroscopy of the inner regions of the source. We show that the region has a bipolar structure, and contains a variety of Class I and II YSOs. Much of the MIR emission appears to be dominated by PAH emission bands, which cause strong increases in flux in the 5.8 and 8.0 microns photometric channels, whilst the variation of H_alpha, [NII] at 6583 A, [SII] at 6716+6731 A, and MIR emission profiles confirms the presence of complex ionisation fronts, and ionisation stratification.