Variations in the Star Formation Efficiency of the Dense Molecular Gas across the Disks of Star-Forming Galaxies

@article{Usero2015VariationsIT,
  title={Variations in the Star Formation Efficiency of the Dense Molecular Gas across the Disks of Star-Forming Galaxies},
  author={Antonio Usero and Adam K. Leroy and Fabian Walter and Andreas Schruba and Santiago Garc'ia-Burillo and Karin M. Sandstrom and Frank Bigiel and Elias Brinks and Carsten Kramer and Erik W Rosolowsky and Karl F. Schuster and W.J.G. de Blok},
  journal={arXiv: Astrophysics of Galaxies},
  year={2015}
}
We present a new survey of HCN(1-0) emission, a tracer of dense molecular gas, focused on the little-explored regime of normal star-forming galaxy disks. Combining HCN, CO, and infrared (IR) emission, we investigate the role of dense gas in Star Formation (SF), finding systematic variations in both the apparent dense gas fraction and the apparent SF efficiency (SFE) of dense gas. The latter may be unexpected, given the popularity of gas density threshold models to explain SF scaling relations… 
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