English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The observed anti-correlation between the central dark matter (DM) densitiesof the bright Milky Way (MW) dwarf spheroidal galaxies (dSphs) and theirorbital pericenter distances poses a potential signature of self-interactingdark matter (SIDM). In this work we investigate this possibility by analysingthe range of SIDM scattering cross section per unit mass, $\sigma/m_{\chi}$,able to explain such anti-correlation. We simulate the orbital evolution ofdSphs subhaloes around the MW assuming an analytical form for the gravitationalpotential, adopting the proper motions from the Gaia mission and including aconsistent characterization of gravitational tidal stripping. The evolution ofthe subhaloes density profile is modelled using the gravothermal fluidformalism, where DM particle collisions induce thermal conduction that dependson $\sigma/m_{\chi}$. We find that models of dSphs, such as Carina and Fornax,reproduce the observed central DM densities with fixed $\sigma/m_{\chi}$ranging between $30$ and $50$ cm$^{2}$g$^{-1}$, whereas other dSphs preferlarger values ranging between $70$ and $100$ cm$^{2}$g$^{-1}$. These crosssections correlate with the average collision velocity of DM particles withineach subhalo's core, so that systems modelled with large cross sections havelower collision velocities. We fit the cross section-velocity correlation witha SIDM particle model, where a DM particle of mass $m_{\chi}=0.648\pm 0.154$GeV interacts under the exchange of a light mediator of mass $m_{\phi}=0.636\pm0.055$ MeV, with the self-interactions being described by a Yukawa potential.The outcome is a cross section-velocity relation that explains the diverse DMprofiles of MW dSph satellites and is consistent with observational constraintson larger scales.

Constraining Velocity-dependent Self-Interacting Dark Matter with the Milky Way's dwarf spheroidal galaxies