2. Removal of abnormality in the stiffest equation and upper bound on neutron star masses
We have tried to remove the abnormality in the stiffest EOS by the following method:
We truncate the density from a finite nuclear density to zero in a small region by assuming an envelope of the EOS of adiabatic polytrope (Tooper 1965), dd, where is the rest mass density and is the (constant) adiabatic index. The use of a polytropic equation is justified because - (i) it gives a theoretical simplification which does not affect the results very much, and (ii) this choice also maintains the continuity of and at the core-envelope boundary.
The degree of softness of the envelope is determined by the boundary conditions to obtain the maximum value of u, and hence a maximum value of neutron star mass, because for a given value of rotation period, the maximum mass of the configuration depends only upon the corresponding maximum value of u [This is evident from Eq. (12), given later on].
© European Southern Observatory (ESO) 2000
Online publication: December 17, 1999