at the origin, thus guaranteeing the above mentioned condition). Finally, the relevance of crowding is controlled by the effective packing fraction $$\phi=\frac{\pi N}{4L_xL_y} \, .$$ The collective behavior of the system is purely controlled by these three dimensionless parameters: $\phi$, $\text{Pe}$ and $\text{g}$. In this work we focus on the phase behavior of Aligning Active Brownian Particles at fixed $\phi=0.1$ and investigate in detail the role played by velocity alignment and excluded volume interactions.

In the weak coupling limit, $\text{g} \to 0$, we recover the (isotropic) ABP model, which has become over the last years the prototypical model to study the competition between steric effects and self-propulsion. As it has been largely discussed in the literature [@CatesRev; @Fily2012; @Redner2013; @Stenhammar2014; @Levis2017], at high enough density and activity, the combination of excluded volume interactions and self-propulsion provokes a Motility-Induced Phase Separation (MIPS). Here, we analyze systems which lie below the critical packing fraction and Péclet number needed in order to nucleate a macroscopic cluster from an homogenous state and observe MIPS. In this regime, ABP show a clear tendency to form clusters that do not coarsen above a certain size [@Fily2012; @Levis2014; @Levis2017].

In the limit of point-like particles ($\epsilon\to 0$), 