The BPT Diagram in Cosmological Galaxy Formation Simulations: Understanding the Physics Driving Offsets at High Redshift

  title={The BPT Diagram in Cosmological Galaxy Formation Simulations: Understanding the Physics Driving Offsets at High Redshift},
  author={Prerak Garg and Desika Narayanan and Nell Byler and Ryan L. Sanders and Alice E. Shapley and Allison L. Strom and Romeel Dav'e and Michaela Hirschmann and Christopher C. Lovell and Justin A. Otter and Gerg{\"o} Popping and George C. Privon},
  journal={The Astrophysical Journal},
The Baldwin, Philips, & Terlevich diagram of [O iii]/Hβ versus [N ii]/Hα (hereafter N2-BPT) has long been used as a tool for classifying galaxies based on the dominant source of ionizing radiation. Recent observations have demonstrated that galaxies at z ∼ 2 reside offset from local galaxies in the N2-BPT space. In this paper, we conduct a series of controlled numerical experiments to understand the potential physical processes driving this offset. We model nebular line emission in a large… 

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