A rumble in the dark: signatures of self-interacting dark matter in Super-Massive Black Hole dynamics and galaxy density profiles

Understand

We explore for the first time the effect of self-interacting dark matter (SIDM) on the dark matter (DM) and baryonic distribution in massive galaxies formed in hydrodynamical cosmological simulations, including explicit baryonic physics treatment.

• A novel implementation of Super-Massive Black Hole (SMBH) formation and evolution is used, as in Tremmel et al.(2015, 2016), allowing to explicitly follow SMBH dynamics at the center of galaxies.
• A high SIDM constant cross-section is chosen, $\sigma$=10 $\rm cm^2/gr$, to amplify differences from CDM models.
• Milky Way-like galaxies form a shallower DM density profile in SIDM than they do in CDM, with differences already at 20 kpc scales.