The Physical Origin of Long Gas Depletion Times in Galaxies

@article{Semenov2017ThePO,
  title={The Physical Origin of Long Gas Depletion Times in Galaxies},
  author={Vadim A. Semenov and Andrey V. Kravtsov and Nickolay Y. Gnedin},
  journal={The Astrophysical Journal},
  year={2017},
  volume={845}
}
We present a model that explains why galaxies form stars on a timescale significantly longer than the timescales of processes governing the evolution of interstellar gas. We show that gas evolves from a non-star-forming to a star-forming state on a relatively short timescale, and thus the rate of this evolution does not limit the star formation rate (SFR). Instead, the SFR is limited because only a small fraction of star-forming gas is converted into stars before star-forming regions are… 

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