The varying mass distribution of molecular clouds across M83

• Verfasst von: Freeman, Pamela [VerfasserIn]
• Verfasst von: Kruijssen, Diederik [VerfasserIn]
• Titel: The varying mass distribution of molecular clouds across M83
• Verf.angabe: Pamela Freeman, Erik Rosolowsky, J.M. Diederik Kruijssen, Nate Bastian and Angela Adamo
• E-Jahr: 2017
• Jahr: 28 February 2017
• Umfang: 13 S.
• Fussnoten: Gesehen am 19.10.2017
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2017
• Band/Heft Quelle: 468(2017), 2, Seite 1769-1781
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stx499
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1564572609

Abstract

The work of Adamo et al. showed that the mass distributions of young massive stellar clusters were truncated above a maximum-mass scale in the nearby galaxy M83 and that this truncation mass varies with the galactocentric radius. Here, we present a cloud-based analysis of Atacama Large Millimeter/submillimeter Array CO(1 → 0) observations of M83 to search for such a truncation mass in the molecular cloud population. We identify a population of 873 molecular clouds in M83 that is largely similar to those found in the Milky Way and Local Group galaxies, though clouds in the centre of the galaxy show high surface densities and enhanced turbulence, as is common for clouds in high-density nuclear environments. Like the young massive clusters, we find a maximum-mass scale for the molecular clouds which decreases radially in the galaxy. We find that the most young massive cluster tracks the most massive molecular cloud with the cluster mass being 10−2 times that of the most massive molecular cloud. Outside the nuclear region of M83 (Rg > 0.5 kpc), there is no evidence for changing internal conditions in the population of molecular clouds, with the average internal pressures, densities and free-fall times remaining constant for the cloud population over the galaxy. This result is consistent with the bound cluster formation efficiency depending only on the large-scale properties of the interstellar medium rather than the internal conditions of individual clouds.