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Abstract:

The preference for cored dark matter density profiles in dwarf disk galaxies has long stirred tensions over the internal structure of dark matter halos, further complicating the Cold Dark Matter (CDM) crisis at sub-galactic scales. Kinematic measurements of stars in the even more dark matter-dominated dwarf spheroidal (dSph) satellites of the Milky Way offer a promising, less baryon-contaminated avenue to revisit these issues. As data on individual member stars improve in both precision and sample size, dynamical estimates of their underlying mass distributions are becoming increasingly accessible. However, the inferred dark matter density profiles often stand in conflict with one another, revealing inconsistencies across galaxies.
We, therefore, attempt to extract more information contained in the non-uniform shape of the line-of-sight velocity distribution, which is assumed to be fixed in traditional Jeans modeling. This is achieved by invoking the stars’ higher-order velocity moments alongside their standard velocity dispersion. We demonstrate the model’s improved capacity for recovering dark matter density profiles and discuss its inherent limitations.
In addition, we explore the implications of our model within the context of fuzzy dark matter (FDM) theory, an alternative to CDM that gained growing attention for its potential to reconcile observations and theory. We provide preliminary constraints on the FDM particle mass necessary to address the core-cusp tension observed in classical Milky Way dSphs.