Real and counterfeit cores: how feedback expands halos and disrupts tracers of inner gravitational potential in dwarf galaxies

Understand

The tension between the diverging density profiles in Lambda Cold Dark Matter ($\Lambda$CDM) simulations and the constant-density inner regions of observed galaxies is a long-standing challenge known as the `core-cusp' problem.

• We demonstrate that the \texttt{SMUGGLE} galaxy formation model implemented in the \textsc{Arepo} moving mesh code forms constant-density cores in idealized dwarf galaxies of $M_\star \approx 8 \times 10^7$ M$_{\odot}$ with initially cuspy dark matter halos of $M_{200} \approx 10^{10}$ M$_{\odot}$.
• Identical initial conditions run with the Springel and Hernquist (2003; SH03) feedback model preserve cuspiness.
• Literature on the subject has pointed to the low density threshold for star formation, $\rho_\text{th}$, in SH03-like models as an obstacle to baryon-induced core formation.