Star formation in Galactic spiral arms and the inter-arm regions

TL;DR

This study investigates whether the efficiency of dense clump formation within molecular clouds varies between spiral arms and inter-arm regions in the Galaxy, finding no significant difference along the studied line of sight.

Contribution

It provides observational evidence that large-scale Galactic structures do not significantly influence dense clump formation efficiency outside the Galactic Centre.

Findings

No difference in clump formation efficiency between spiral arms and inter-arm regions.

Large-scale Galactic structures have minimal impact on dense, star-forming structures.

Supports the idea that local cloud conditions dominate star formation processes.

Abstract

The line of sight through the Galactic Plane between longitudes l = 37.83 degr and l = 42.50 degr allows for the separation of Galactic Ring Survey molecular clouds into those that fall within the spiral arms and those located in the inter-arm regions. By matching these clouds in both position and velocity with dense clumps detected in the mm continuum by the Bolocam Galactic Plane Survey, we are able to look for changes in the clump formation efficiency (CFE), the ratio of clump-to-cloud mass, with Galactic environment. We find no evidence of any difference in the CFE between the inter-arm and spiral-arm regions along this line of sight. This is further evidence that, outside the Galactic Centre region, the large-scale structures of the Galaxy play little part in changing the dense, potentially star-forming structures within molecular clouds.