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

In recent years our understanding of the dense matter equation of state (EOS)of neutron stars has significantly improved by analyzing multimessenger datafrom radio/X-ray pulsars, gravitational wave events, and from nuclear physicsconstraints. Here we study the additional impact on the EOS from the jointlyestimated mass and radius of PSR J0740+6620, presented in Riley et al. (2021)by analyzing a combined dataset from X-ray telescopes NICER and XMM-Newton. Weemploy two different high-density EOS parameterizations: a piecewise-polytropic(PP) model and a model based on the speed of sound in a neutron star (CS). Atnuclear densities these are connected to microscopic calculations of neutronmatter based on chiral effective field theory interactions. In addition to thenew NICER data for this heavy neutron star, we separately study constraintsfrom the radio timing mass measurement of PSR J0740+6620, the gravitationalwave events of binary neutron stars GW190425 and GW170817, and for the latterthe associated kilonova AT2017gfo. By combining all these, and the NICERmass-radius estimate of PSR J0030+0451 we find the radius of a 1.4 solar massneutron star to be constrained to the 95% credible ranges 12.33^{+0.76}_{-0.81}km (PP model) and 12.18^{+0.56}_{-0.79} km (CS model). In addition, we exploredifferent chiral effective field theory calculations and show that the newNICER results provide tight constraints for the pressure of neutron star matterat around twice saturation density, which shows the power of these observationsto constrain dense matter interactions at intermediate densities.

the astrophysical journal. letters

Constraints on the dense matter equation of state and neutron star  properties from NICER's mass-radius estimate of PSR J0740+6620 and  multimessenger observations