The physical origins of low-mass spin bias

Understand

At $z=0$, higher-spin haloes with masses above $\log(\text{M}_{\text{c}}/h^{-1}\text{M}_\odot)\simeq 11.5$ have a higher bias than lower-spin haloes of the same mass.

• However, this trend is known to invert below this characteristic crossover mass, $\text{M}_{\text{c}}$.
• In this paper, we measure the redshift evolution and scale dependence of halo spin bias at the low-mass end and demonstrate that the inversion of the signal is entirely produced by the effect of splashback haloes.
• These low-mass haloes tend to live in the vicinity of significantly more massive haloes, thus sharing their large-scale bias properties.