Multi-scale analysis of the Monoceros OB 1 star-forming region: I. The dense core population

Abstract

Current theories and models attempt to explain star formation globally, from core scales to giant molecular cloud scales. A multi-scale observational characterisation of an entire molecular complex is necessary to constrain them. We investigate star formation in G202.3+2.5, a ~10x3 pc sub-region of the Monoceros OB1 cloud with a complex morphology harbouring interconnected filamentary structures. We aim to connect the evolution of cores and filaments in G202.3+2.5 with the global evolution of the cloud and to identify the engines of the cloud dynamics. In this first paper, the star formation activity is evaluated by surveying the distributions of dense cores and protostars, and their evolutionary state, as characterised using both infrared observations from the Herschel and WISE telescopes and molecular line observations with the IRAM 30-m telescope. We find ongoing star formation in the whole cloud, with a local peak in star formation activity around the centre of G202.3+2.5 where a chain of massive cores (10-50 Msun) forms a massive ridge (>150 Msun). All evolutionary stages from starless cores to Class II protostars are found in G202.3+2.5, including a possibly starless, large column density (8x10^{22} cm-2), and massive (52 Msun) core. All the core-scale observables examined in this paper point to an enhanced star formation activity centred on the junction between the three main branches of the ramified structure of G202.3+2.5. This suggests that the increased star-formation activity results from the convergence of these branches. To further investigate the origin of this enhancement, it is now necessary to extend the analysis to larger scales, in order to examine the relationship between cores, filaments and their environment. We address these points through the analysis of the dynamics of G202.3+2.5 in a joint paper.

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Cited by in corpus (9)

• Multi-scale analysis of the Monoceros OB 1 star-forming region: II. Colliding filaments in the Monoceros OB1 molecular cloud
• A Naive Bayes Classifier for identifying Class II YSOs
• Large-scale magnetic field in the Monoceros OB-1 East molecular cloud
• Spatial and dynamical structure of the NGC 2264 star-forming region
• Characterization of dense Planck clumps observed with Herschel and SCUBA-2
• Cloud structures in M17 SWex : Possible cloud-cloud collision
• Comparison of Herschel and ArTéMiS observations of massive filaments
• Monoceros OB4: a new association in Gaia DR2
• A Gaia view on the star formation in the Monoceros OB1 and R1 associations