Gas structure and dynamics towards bipolar infrared bubble

TL;DR

This study uses multi-wavelength CO observations to analyze the structure and dynamics of four bipolar infrared bubbles, revealing their associations with filaments, clumps, and star formation activities.

Contribution

It provides detailed gas structure and dynamics analysis of bipolar bubbles, clarifying their formation and expansion mechanisms using CO data.

Findings

G045.386-0.726 is two separate bubbles at different distances.

G049.998-0.125 and G051.610-0.357 are associated with filaments.

G050.489+0.993's lobes are expanding into a clump.

Abstract

We present multi-wavelength analysis for four bipolar bubbles (G045.386-0.726, G049.998-0.125, G050.489+0.993, and G051.610-0.357) to probe the structure and dynamics of their surrounding gas. The 12CO J=1-0, 13CO J=1-0 and C18O J=1-0 observations are made with the Purple Mountain Observation (PMO) 13.7 m radio telescope. For the four bipolar bubbles, the bright 8.0 um emission shows the bipolar structure. Each bipolar bubble is associated with an HII region. From CO observations we find that G045.386-0.726 is composed of two bubbles with different distances, not a bipolar bubble. Each of G049.998-0.125 and G051.610-0.357 is associated with a filament. The filaments in CO emission divide G049.998-0.125 and G051.610-0.357 into two lobes. We suggest that the exciting stars of both G049.998-0.125 and G051.610-0.357 form in a sheet-like structure clouds. Furthermore, G050.489+0.993 is associated with a clump, which shows a triangle-like shape with a steep integrated intensity gradient towards the two lobes of G050.489+0.993. We suggest that the two lobes of G050.489+0.993 have simultaneously expanded into the clump.