Giant molecular cloud populations in nearby galaxies

Annie Hughes, Sharon Meidt, Dario Colombo, Andreas Schruba, Eva Schinnerer, Adam Leroy, Tony Wong

Research output: Contribution to journalArticlepeer-review


We present new results from a comparative analysis of the resolved giant molecular cloud (GMC) populations in six nearby galaxies. We show that the GMCs in denser environments-M51, the centre of NGC6946-have greater CO surface brightness and higher velocity dispersions relative to their size than GMCs in less dense environments. We find systematic differences in the GMC mass distribution among galaxies, such that more of the molecular gas in the low-mass galaxies (M33, the Large Magellanic Cloud) and the outer disk of M31 is located in low mass clouds. Using the number density of GMCs in the interarm regions of M51, we argue that GMC destruction in this region is regulated by shear, and that cloud lifetimes there are finite and short, ~20 to 30 Myr. Our results indicate the importance of galactic environment on the evolution of GMCs, and on a galaxy's global pattern of star formation.

Original languageEnglish (US)
Pages (from-to)30-37
Number of pages8
JournalProceedings of the International Astronomical Union
Issue numberS315
StatePublished - Aug 1 2015


  • (Galaxies:) Local Group
  • (Galaxies:) Magellanic Clouds
  • Galaxies: ISM
  • ISM: Clouds

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Astronomy and Astrophysics
  • Nutrition and Dietetics
  • Public Health, Environmental and Occupational Health
  • Space and Planetary Science


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