The Cusp/Core problem: supernovae feedback versus the baryonic clumps and dynamical friction model

Abstract

In the present paper, we compare the predictions of two well known mechanisms considered able to solve the cusp/core problem (a. supernova feedback; b. baryonic clumps-DM interaction) by comparing their theoretical predictions to recent observations of the inner slopes of galaxies with masses ranging from dSphs to normal spirals. We compare the $\alpha$-$V_{\rm rot}$ and the $\alpha$-$M_{\ast}$ relationships, predicted by the two models with high resolution data coming from \citep{Adams2014,Simon2005}, LITTLE THINGS \citep{Oh2015}, THINGS dwarves \citep{Oh2011a,Oh2011b}, THINGS spirals \citep{Oh2015}, Sculptor, Fornax and the Milky Way. The comparison of the theoretical predictions with the complete set of data shows that the two models perform similarly, while when we restrict the analysis to a smaller subsample of higher quality, we show that the method presented in this paper (baryonic clumps-DM interaction) performs better than the one based on supernova feedback. We also show that, contrarily to the first model prediction, dSphs of small mass could have cored profiles. This means that observations of cored inner profiles in dSphs having a stellar mass $<10^6 M_{\odot}$ not necessarily imply problems for the $\Lambda$CDM model.