The SEDIGISM survey: Molecular cloud morphology

II. Integrated source properties

¹ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
e-mail: kneralwar@mpifr-bonn.mpg.de
² School of Physics & Astronomy, Cardiff University, Queen’s Building, The Parade, Cardiff CF24 3AA, UK
³ Centre for Astrophysics and Planetary Science, University of Kent, Canterbury CT2 7NH, UK
⁴ Laboratoire d’Astrophysique (AIM), CEA, CNRS, Université Paris-Saclay, Université Paris Diderot, Sorbonne Paris Cité, 91191 Gif-sur-Yvette, France
⁵ Space Science Institute, 4765 Walnut St Suite B, Boulder, CO 80301, USA
⁶ School of Science and Technology, University of New England, Armidale NSW 2351, Australia
⁷ I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937 Cologne, Germany
⁸ Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Brownlow Hill, Liverpool, L3 5RF, UK
⁹ Laboratoire d’astrophysique de Bordeaux, CNRS, Univ. Bordeaux, B18N, allée Geoffroy Saint-Hilaire, 33615 Pessac, France
¹⁰ School of Physics and Astronomy, University of Exeter, Stocker Road, Exeter EX4 4QL, UK
¹¹ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
¹² Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
¹³ INAF – Osservatorio Astronomico di Cagliari, Via della Scienza 5, 09047 Selargius (CA), Italy
¹⁴ The American University of Paris, 2bis, Passage Landrieu 75007 Paris, France

Received: 22 October 2021
Accepted: 4 May 2022

Abstract

The Structure, Excitation, and Dynamics of the Inner Galactic InterStellar Medium (SEDIGISM) survey has produced high (spatial and spectral) resolution ¹³CO (2−1) maps of the Milky Way. It has allowed us to investigate the molecular interstellar medium in the inner Galaxy at an unprecedented level of detail and characterise it into molecular clouds (MCs). In a previous paper, we classified the SEDIGISM clouds into four morphologies. However, how the properties of the clouds vary for these four morphologies is not well understood. Here, we use the morphological classification of SEDIGISM clouds to find connections between the cloud morphologies, their integrated properties, and their location on scaling relation diagrams. We observe that ring-like clouds show the most peculiar properties, having, on average, higher masses, sizes, aspect ratios, and velocity dispersions, compared to other morphologies. We speculate that this is related to the physical mechanisms that regulate their formation and evolution; for example, turbulence from stellar feedback can often result in the creation of bubble-like structures. We also see a trend of morphology with the virial parameter, whereby ring-like, elongated, clumpy, and concentrated clouds have virial parameters in decreasing order. Our findings provide a foundation for a better understanding of MC behaviour, based on their measurable properties.