Neutron stars with hyperon cores: stellar radii and EOS near nuclear density

Mar 27, 2014, 4:15 PM
20m

Speaker

Prof. Pawel Haensel (Nicholaus Copernicus Astronomical Centre, Warsaw, Poland)

Description

We study the impact of the presence of a hyperon core on the R-M relation for neutron stars (NS). Using observational constraint Mmax>2Msun, and available EOSs, we show difference between R-M relation in the mass range 1.2 - 1.6 Msun between NS with nucleon cores and those based on EOS that allow for sizable hyperon cores in high mass NS. We find correlation between pressure at normal nuclear density n_0 and R(1.4Msun) and we critically discuss arguments against the presence of hyperon cores in massive NS. We argue that future LOFT mission with better than 5% precision of measuring simultaneously R and M of NS in some X-ray sources will have potential to rule out sizable hyperon cores in NS.

Primary authors

Dr Julian Leszek Zdunik (Nicholaus Copernicus Astronomical Centre, Warsaw, Poland) Dr Michal Bejger (Nicholaus Copernicus Astronomical Centre, Warsaw, Poland) Prof. Pawel Haensel (Nicholaus Copernicus Astronomical Centre, Warsaw, Poland)

Presentation materials