From Clumps to Cores to Protostars: The JCMT Gould Belt Survey's "First-Look" analysis of Southern Orion A using SCUBA-2

TL;DR

This study analyzes the southern Orion A molecular cloud using SCUBA-2 data, identifying structures and examining the distribution and evolution of young stellar objects, revealing insights into star formation processes.

Contribution

It introduces a two-step structure identification method for submillimeter data and investigates the spatial distribution and evolution of young stellar objects in Orion A.

Findings

Identification of 'islands' and 'fragments' in Orion A

Correlation between concentration, Jeans stability, and star formation

Observed velocity dispersion evolution from Class 0 to Class II objects

Abstract

We present a subset of the James Clerk Maxwell Telescope Gould Belt Survey's "first-look" results of the southern extent of the Orion A molecular cloud. Employing a two-step structure identification process, we constructed individual catalogues for large-scale regions of significant emission labeled as "islands" and smaller-scale subregions called "fragments" using the 850 $\mu$m continuum maps obtained using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2). We highlight the relationship between the concentration and Jeans stability for regions of significant emission and present the results of an investigation into the spatial distribution of Young Stellar Objects detected using the Spitzer Space Telescope and the Herschel Space Observatory. We find an apparent evolution in the velocity dispersion from Class 0 to Class II objects which we derive from comparing our observations to a simple model.