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 Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The significant diversity of rotation curve (RC) shapes in dwarf galaxies hasrecently emerged as a challenge to LCDM: in dark matter (DM) only simulations,DM halos have a universal cuspy density profile that results in self-similar RCshapes. We compare RC shapes of simulated galaxies from the NIHAO project withobserved galaxies from the homogeneous SPARC dataset. The DM halos of the NIHAOgalaxies can expand to form cores, with the degree of expansion depending ontheir stellar-to-halo mass ratio. By means of the $V_{\rm 2kpc}-V_{\rm Rlast}$relation (where $V_{\rm Rlast}$ is the outermost measured rotation velocity),we show that both the average trend and the scatter in RC shapes of NIHAOgalaxies are in reasonable agreement with SPARC: this represents a significantimprovement compared to simulations that do not result in DM core formation,suggesting that halo expansion is a key process in matching the diversity ofdwarf galaxy RCs. Note that NIHAO galaxies can reproduce even the extremelyslowly rising RCs of IC 2574 and UGC 5750. Revealingly, the range whereobserved galaxies show the highest diversity corresponds to the range wherecore formation is most efficient in NIHAO simulations, 50$<V_{\rm Rlast}$\kms$^{-1}<$100. A few observed galaxies in this range cannot be matched by anyNIHAO RC nor by simulations that predict a universal halo profile.Interestingly, the majority of these are starbursts or emission-line galaxies,with steep RCs and small effective radii. Such galaxies represent aninteresting observational target providing new clues to the process/viabilityof cusp-core transformation, the relationship between starburst and innerpotential well, and the nature of DM.

NIHAO XIV: Reproducing the observed diversity of dwarf galaxy rotation curve shapes in LCDM