Molecular cloud determination in the Northern Galactic Plane

TL;DR

This paper introduces a hierarchical, threshold-based method for identifying molecular clouds and clumps in the Northern Galactic Plane using CO survey data, aiming to enhance understanding of galactic structure and star formation conditions.

Contribution

It presents a novel methodology for cloud and clump detection that preserves hierarchical information and applies it to a large galactic survey, creating a comprehensive catalogue.

Findings

Catalogue covers majority of Northern Galactic Plane

Identifies clouds with little or no star formation

Provides insights into molecular structure and star formation conditions

Abstract

The Exeter FCRAO CO Galactic Plane Survey consists of 12CO and 13CO (J=1-0) observations over the galactic plane covering 55 degrees <= l <= 102 degrees, |b| >= 1 degree and 141 degrees <= l <= 195 degrees, -3.5 degrees <= b <= 5.5 degrees with a spatial resolution of ~45" and a spectral resolution of ~0.15km/s. We will present the methodology of a threshold-based cloud and clump determination method which retains hierarchical information, then discuss associating sources with clouds in the catalogue. Once complete, this catalogue of clouds and clumps will encompass the majority of the Northern Galactic Plane, providing knowledge of the molecular structure of the galaxy and the starting point for studies of the variation in star formation efficiency. In addition, it will allow us to identify clouds that have no or little star formation taking place inside them, which are often overlooked in the study of the conditions required for star formation to take place.