THE PdBI ARCSECOND WHIRLPOOL SURVEY (PAWS): ENVIRONMENTAL DEPENDENCE OF GIANT MOLECULAR CLOUD PROPERTIES IN M51

By D. Colombo, Annie Hughes, E. Schinnerer, S. Meidt, A. Leroy, Jérome Pety, C. Dobbs, S. García-Burillo, G. Dumas, T. Thompson and 2 more. 2014

148 citations recorded by the source corpus.

Using data from the PdBI Arcsecond Whirlpool Survey (PAWS), we have generated the largest extragalactic giant molecular cloud (GMC) catalog to date, containing 1507 individual objects. GMCs in the inner M51 disk account for only 54% of the total 12CO(1–0) luminosity of the survey, but on average they exhibit physical properties similar to Galactic GMCs. We do not find a strong correlation between the GMC size and velocity dispersion, and a simple virial analysis suggests that ∼30% of GMCs in M51 are unbound. We have analyzed the GMC properties within seven dynamically motivated galactic environments, finding that GMCs in the spiral arms and in the central region are brighter and have higher velocity dispersions than inter-arm clouds. Globally, the GMC mass distribution does not follow a simple power-law shape. Instead, we find that the shape of the mass distribution varies with galactic environment: the distribution is steeper in inter-arm region than in the spiral arms, and exhibits a sharp truncation at high masses for the nuclear bar region. We propose that the observed environmental variations in the GMC properties and mass distributions are a consequence of the combined action of large-scale dynamical processes and feedback from high-mass star formation. We describe some challenges of using existing GMC identification techniques for decomposing the 12CO(1–0) emission in molecule-rich environments, such as M51's inner disk.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/4a73ee9f68457e0c0604ce0224fe0e206118d562

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Citations in the corpus

The Formation and Destruction of Molecular Clouds and Galactic Star Formation (2015, background): “This tendency is actually observed in Milky Way outer disk, LMC, M33, and M51 (Rosolowsky 2005; Wong et al. 2011; Gratier et al. 2012; Hughes et al. 2010; Colombo et al. 2014) .”
FIRE-2 simulations: physics versus numerics in galaxy formation (2017, background): “…projected mass-weighted rms radius), to observations of nearby galaxies ((Bolatto et al. 2008; Fukui et al. 2008; Heyer et al. 2009; Muraoka et al. 2009; Roman-Duval et al. 2010; Colombo et al. 2014; Heyer & Dame 2015; Tosaki et al. 2017); note our definition of Rcloud is equivalent to their σr).”
Molecular Clouds in the Milky Way (2015, background): “Thus, ALMA can extend many of the analyses discussed in this review to molecular clouds residing within nearby galaxies (Bolatto et al. 2008, Colombo et al. 2014, Leroy et al. 2015).”
Cloud-scale Molecular Gas Properties in 15 Nearby Galaxies (2018, background): “Such variations have been emphasized in individual galaxies before (e.g., Koda et al. 2009; Colombo et al. 2014a).”
Dawes Review 4: Spiral Structures in Disc Galaxies (2014, background): “Colombo et al. (2014) found evidence for an underlying flocculent spiral in the grand-design spiral M51, proposed for the old stars as well as the gas (CO).”
Probing the role of the galactic environment in the formation of stellar clusters, using M83 as a test bench (2015, background): “In the M51 galaxy, Colombo et al. (2014) report clear differences in the number, mass, luminosity, density, and mass distributions of GMCs within different environments of the galaxy (e.g. inter-arm and arm regions, molecular ring, etc.).”