Astron. Astrophys. 353, 641-645 (2000)

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
helpdesk.link@springer.de