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

Recent interest in primordial black holes as a possible dark matter candidatehas motivated the reanalysis of previous methods for constraining massiveastrophysical compact objects in the Milky Way halo and beyond. In order toderive these constraints, a model for the dark matter distribution around theMilky Way must be used. Previous microlensing searches have assumed asemi-isothermal density sphere for this task. We show this model is no longerconsistent with data from the Milky Way rotation curve, and test tworeplacement models, namely NFW and power-law. The power-law model is the mostflexible as it can break spherical symmetry, and best fits the data. Thus, werecommend the power-law model as a replacement, although it still lacks theflexibility to fully encapsulate all possible shapes of the Milky Way halo. Wethen use the power-law model to rederive some previous microlensing constraintsin the literature, while propagating the primary halo-shape uncertaintiesthrough to our final constraints. Our analysis reveals that the microlensingconstraints towards the Large Magellanic Cloud weaken somewhat for MACHO massesaround $10\, M_\odot$ when this uncertainty is taken into account, but theconstraints tighten at lower masses. Exploring some of the simplifyingassumptions of previous constraints we also study the effect of wide massdistributions of compact halo objects, as well as the effect of spatialclustering on microlensing constraints. We find that both effects induce ashift in the constraints towards smaller masses, and can effectively remove themicrolensing constraints from $M \sim 1-10 M_\odot$ for certain MACHOpopulations.

Updating the MACHO fraction of the Milky Way dark halo with improved mass models