The formation of molecular clouds in spiral galaxies

By C. Dobbs, Ian A. Bonnell, J. E. Pringle. 2006

554 citations recorded by the source corpus.

ABSTRACT We present Smoothed Particle Hydrodynamics (SPH) simulations of molecular cloudformation in spiral galaxies. These simulations model the response of a non-self-gravitating gaseous disk to a galactic potential. The spiral shock induces high densitiesin the gas, and considerable structure in the spiral arms, which we identify as molec-ular clouds. We regard the formation of these structures as due to the dynamics ofclumpy shocks, which perturb the ﬂow of gas through the spiral arms. In addition, thespiral shocks induce a large velocity dispersion in the spiral arms, comparable with themagnitude of the velocity dispersion observed in molecular clouds. We estimate theformation of molecular hydrogen, by post-processing our results and assuming the gasis isothermal. Provided the gas is cold (T 6 100 K), the gas is compressed suﬃcientlyin the spiral shock for molecular hydrogen formation to occur in the dense spiral armclumps. These molecular clouds are largely conﬁned to the spiral arms, since mostmolecular gas is photodissociated to atomic hydrogen upon leaving the arms.Key words: galaxies: spiral – hydrodynamics – ISM: clouds – ISM: molecules – stars:formation

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/50bf0fc5c6ec76c97fcd7f8758f70d352b09dc1a

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

A CRITICAL ASSESSMENT OF NONLINEAR FORCE-FREE FIELD MODELING OF THE SOLAR CORONA FOR ACTIVE REGION 10953 (2009, methodology): “The third variant was to use the method of preprocessing described in Fuhrmann et al. (2007), the goals of which are the same as the Wiegelmann et al. (2006), but which uses a simulated annealing numerical scheme to find the optimal B|z0 field.”
Cooling, Gravity, and Geometry: Flow-driven Massive Core Formation (2007, background): “A similar assumption seems valid for spiral shocks in the Galaxy, where the disk potential would again lead to a flattening of the inflows (e.g. Dobbs et al. 2006).”
Nonrelativistic string theory and T-duality (2018, methodology): “An extensive description improving a few results of [5] can be found in [6].”
Homoepitaxial growth of β‐Ga2O3 layers by metal‐organic vapor phase epitaxy (2014, background): “A quantitative analysis of the stacking fault volume by geometrical phase analysis [29] shows that despite the fact that the annealing has led to a decomposition of the layer the total volume of stacking faults and twins reduces.”
KINEMATIC DISTANCES TO MOLECULAR CLOUDS IDENTIFIED IN THE GALACTIC RING SURVEY (2009, background): “Spiral shocks may allow the formation of molecular clouds (Blitz & Shu 1980; Dobbs et al. 2006, 2008; E. J. Tasker & J. C. Tan 2009, in preparation).”
Slow Star Formation in Dense Gas: Evidence and Implications (2006, background): “Unbound GMC/Collapsing Cluster Models One proposed explanation for the low star formation rate in molecular clouds is that GMCs are not bound by gravity (Mac Low & Klessen 2004; Clark & Bonnell 2004; Clark et al. 2005; Dobbs et al. 2006).”
Accurate interatomic force fields via machine learning with covariant kernels (2016, background): “…the best available, state of the art classical force ﬁelds may not guarantee accurate force prediction, as they may incur systematic errors [46, 47], or may be hard to extend to complex chemical compositions [48], so that a technique that can indeﬁnitely re-use all computed QM forces via GP…”
Fast unfolding of communities in large networks (2008, methodology): “…of our algorithm will only be conﬁrmed after looking in detail at the hierarchies found in ad-hoc networks with known hierarchical structure [19] or without community structure (e.g. Erd¨os-Renyi random graphs), or after comparing with other methods incorporating a tunable resolution [33, 38, 39].”
A census of the Wolf–Rayet content in Westerlund 1 from near-infrared imaging and spectroscopy (2006, background): “(i) Four WR stars in Westerlund 1 are newly confirmed here, with nomenclatures of U, V, W, X following Clark & Negueruela (2002), Negueruela & Clark (2005) and Hopewell et al. (2005) , bringing the total number of WR stars to 24.”