2023.10.17 JavierBallesteros
Channel: Coloquio IRyA
Date: 2023-10-18

Speaker info: Dr. Javier Ballesteros, IRyA-UNAM
https://www.irya.unam.mx/web/en/people/research-staff/j-ballesteros

Title: Gravity or turbulence? The Kennicutt-Schmidt relationship
Abstract:
In this talk, I will give an overview of the diversity of Kennicutt-Schmidt relations reported in the literature, Galactic and 
extragalactic, and then, I will derive, from the pure definition of the star formation rate and simple algebra, what we call the `fundamental equation of star formation,'

SFR = \eff Mgas/\tau_ff

(where SFR is the star formation rate, \eff the efficiency per free-fall time, Mgas the mass in gas, and tau_ff the free-fall time). I will show that if \eff is constant, the mass M_gas must be collapsing, and then, with these basic equations, I will show that the wide variety of correlations reported in the literature for local molecular clouds and  external galaxies can be explained in a self-consistent way, provided that there is an understanding of the actual structure of the objects (galactic or extragalactic) under study. These results imply that turbulence has nothing to do with the Kennicutt-Schmidt law.