Non-rotating and rotating neutron stars in the extended field theoretical model

We study the properties of non-rotating and rotating neutron stars for a new set of equations of state (EOSs) with different high density behaviour obtained using the extended field theoretical model. The high density behaviour for these EOSs are varied by varying the $\omega-$meson self-coupling and hyperon-meson couplings in such a way that the quality of fit to the bulk nuclear observables, nuclear matter incompressibility coefficient and hyperon-nucleon potential depths remain practically unaffected. We find that the largest value for maximum mass for the non-rotating neutron star is $2.1M_\odot$. The radius for the neutron star with canonical mass is $12.8 - 14.1$ km provided only those EOSs are considered for which maximum mass is larger than $1.6M_\odot$ as it is the lower bound on the maximum mass measured so far. Our results for the very recently discovered fastest rotating neutron star indicate that this star is supra massive with mass $1.7 - 2.7M_\odot$ and circumferential equatorial radius $12 - 19$ km.

Shashi K. Dhiman, Raj Kumar, B. K. Agrawal · 2007