EPoS Contribution
EPoS Contribution
The physics setting the molecular cloud lifetime

Diederik Kruijssen
ARI/ZAH, Heidelberg, DE
A wide range of recent work shows that galactic star formation (SF) relations between the gas mass (density) and the star formation rate (density) develop substantial scatter or even change form when considered below a certain spatial scale. In this talk, I will present our team's recent work on exploiting this multi-scale behaviour to determine ill-constrained, cloud-scale quantities such as the cloud lifetime, SF/feedback time-scales, SF efficiencies, feedback velocities, mass loading factors, and gravitational instability lengths, using galaxy-scale observations. This new method allows the constraints on SF and feedback from detailed solar neighbourhood studies to be extended across a more representative sample of extragalactic environments. The method has been validated using high-resolution numerical simulations of SF in disc galaxies. Since EPoS 2014, we have applied the formalism to a range of nearby galaxies, providing statistically representative measurements of the above cloud-scale quantities in M33, M31, as well as using high-resolution ALMA Cycle 2 observations of the nearby flocculent spiral NGC 300. These quantities provide a unique insight into the physics setting the molecular cloud lifetime, the star formation efficiency, and the disruption of clouds by feedback. In the ALMA era, our new technique enables the detailed characterisation of the SF process on the cloud scale in galaxies out to z=4, i.e. across a cosmologically representative part of the galaxy population rather than the limited sample of Local Group galaxies where such measurements were previously possible. This enables the systematic study of SF physics as a function of the cosmic environment.
A. Schruba, MPE, DE
S. Longmore, LJMU, UK
D. Haydon, ARI/ZAH, DE
A. Hygate, MPIA, DE
L. Tacconi, MPE, DE
E. van Dishoeck, Leiden, NL
J. Dalcanton, Washington U, US
Key publication

Suggested Session: Galactic Star Formation