Astrophysics Colloquium 9/8/2020 — A New Perspective On The Assembly Of Mass [speaker: Danail Obreschkow, International Centre For Radio Astronomy Research (ICRAR)]
Tuesday September 8, 2020 10:00 am
Linking observable properties of galaxies to the assembly history of their host haloes is one of the great challenges in cosmology. In this colloquium, I will address this challenge from
the view-point of the “tree entropy”, an interesting mathematical way to characterize the structure merger trees. The tree entropy puts every halo merger tree on a scale between a “minimal tree”, grown entirely by smooth accretion, and a “maximal tree”, grown exclusively by equal-mass major mergers. I will try my best to provide an intuitive geometric way to think about this entropy. I will then discuss the tree entropies found in a LCDM cosmology and elaborate on how the properties of simulated galaxies relate to their tree entropies. The talk will end with an inspiring illustration of how the tree entropy of the Milky Way, inferred from GAIA data, can help us understand the Galaxy’s morphology.
Host: Paul Schechter
Danail Obreschkow, International Centre for Radio Astronomy, University of Western Australia