colloquium – Stephane Courteau: Puzzles in Galaxy Structure

Galaxies like our Milky Way can be described in terms of their structure,

dynamics, and stellar populations. Some robust correlations between

galaxy structural properties such as stellar mass, circular velocity, and 

size display surprisingly small scatter over many orders of magnitude, 

hinting at well-regulated galaxy formation processes. A major challenge 

to understanding these scaling relations, their tight scatter, and ultimately 

galaxy formation and evolution, is the elusive interplay between visible 

and dark matter.  Among others, the radial acceleration relation, concept 

of “galaxy diversity”, intrinsic scatter in galaxy scaling relations, impact

of supermassive black hole on galaxies, and comparisons with numerical 

simulations of galaxy formation are presented in this context.