IR Dust Bubbles II: Probing the Detailed Structure and Young Massive Stellar Populations of Galactic HII Regions

TL;DR

This study analyzes galactic HII regions' structure and young stellar populations using multi-wavelength surveys, confirming structural features and identifying star formation and ionizing sources.

Contribution

It provides detailed analysis of parsec-sized bubbles, confirming structural models and identifying star formation sites and ionizing sources in less energetic bubbles.

Findings

Confirmed PDR structure surrounds hot dust and ionized gas

Estimated dynamical ages of bubbles using numerical models

Identified candidate YSOs and potential triggered star formation sites

Abstract

We present an analysis of late-O/early-B-powered, parsec-sized bubbles and associated star-formation using 2MASS, GLIMPSE, MIPSGAL and MAGPIS surveys. Three bubbles were selected from the Churchwell et al. (2007) catalog. We confirm that the structure identified in Watson et al. (2008) holds in less energetic bubbles, i.e. a PDR, identified by 8 um emission due to PAHs surrounds hot dust, identified by 24 um emission and ionized gas, identified by 20 cm continuum. We estimate the dynamical age of two bubbles by comparing bubble sizes to numerical models of Hosokawa & Inutsuka (2006). We also identify and analyze candidate young stellar objects (YSOs) using SED fitting and identify sites of possible triggered star-formation. Lastly, we identify likely ionizing sources for two sources based on SED fitting.