Principal determinants of circumgalactic and intragroup thermal energy

Determine whether thermal energy and halo mass follow a power-law relation in lower-mass halos, and identify whether mass alone or additional astrophysical properties such as star formation, nuclear activity, and richness should serve as the principal scaling variables.

Background

The paper argues that mass is an adequate predictor of thermal energy mainly in gravity-dominated massive halos, whereas feedback, cooling, mergers, accretion, and environmental richness can become important in lower-mass systems. The authors therefore leave unresolved both the functional form of the thermal-energy scaling relation and the set of physical properties that should determine it. They specifically identify star-forming and nuclear activity and halo richness as possible additional predictors.