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

Microlensing provides a unique tool to break the stellar to dark matterdegeneracy in the inner Milky Way. We combine N-body dynamical models fitted tothe Milky Way's Boxy/Peanut bulge with exponential disk models outside this,and compute the microlensing properties. Considering the range of modelsconsistent with the revised MOA-II data, we find low dark matter fractions inthe inner Galaxy: at the peak of their stellar rotation curve a fraction$f_v=(0.88\pm0.07)$ of the circular velocity is baryonic (at $1\sigma$, $f_v >0.72$ at $2\sigma$). These results are in agreement with constraints from theEROS-II microlensing survey of brighter resolved stars, where we find$f_v=(0.9\pm0.1)$ at $1\sigma$. Our fiducial model of a disk with scale length2.6kpc, and a bulge with a low dark matter fraction of 12%, agrees with boththe revised MOA-II and EROS-II microlensing data. The required baryonicfractions, and the resultant low contribution from dark matter, are consistentwith the NFW profiles produced by dissipationless cosmological simulations inMilky Way mass galaxies. They are also consistent with recent prescriptions forthe mild adiabatic contraction of Milky Way mass haloes without the need forstrong feedback, but there is some tension with recent measurements of thelocal dark matter density. Microlensing optical depths from the larger OGLE-IIIsample could improve these constraints further when available.

MOA-II Galactic Microlensing Constraints: The Inner Milky Way has a Low Dark Matter Fraction and a Near Maximal Disk