The musca molecular cloud: The perfect 'filament' is still a sheet. Issue 3 (10th June 2022)

• Record Type: Journal Article
• Authors: Tritsis, A; Bouzelou, F; Skalidis, R; Tassis, K; Enßlin, T; Edenhofer, G
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 514:Issue 3(2022)
• Page Start: 3593
• Page End: 3603
• Publication Date: 2022-06-10
• Subjects: radiative transfer -- methods: observational -- ISM: clouds -- ISM: structure; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac1572
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The true three-dimensional (3D) morphology of the Musca molecular cloud is a topic that has received significant attention lately. Given that Musca does not exhibit intense star-formation activity, unveiling its shape has the potential to also reveal crucial information regarding the physics that dictates the formation of the first generation of stars within molecular clouds. Here, we revisit the shape of Musca and we present a comprehensive array of evidence pointing towards a shape that is extended along the line-of-sight dimension: (a) 3D maps of differential extinction; (b) new non-local thermodynamic equilibrium radiative transfer simulations of CO rotational transitions from a sheet-like, magnetically dominated simulated cloud; (c) an effective/critical density analysis of available CO observations; and (d) indirect consequences that a filamentary structure would have had, from a theoretical star-formation perspective. We conclude that the full collection of observational evidence strongly suggests that Musca has a sheet-like geometry.