The maximum mass of differentially rotating neutron stars

¹ Max-Planck-Institut f¨ur Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm, Germany
² Institute of Astronomy, University of Zielona G´ora, Lubuska 2, 65-265 Zielona G´ora, Poland; e-mail: dorota.gondek@obspm.fr
³ LUTH, Observatoire de Paris, Universit´e Paris 7, Place Jules Janssen, 92195 Meudon Cedex, France
⁴ Departament de Fisica Aplicada, Universitat d’Alacant, Apartat de correus 99, 03080 Alacant, Spain
⁵ CAMK, PAN, Bartycka 18, Warsaw, Poland

Abstract

Binary neutron star merger lead to the formation of a massive, rapidly and differentially rotating neutron star (or a strange star) or to the prompt collapse to a black hole. The maximum mass of a differentially rotating remnant is crucial for distinguishing between these two final objects. We study the effect of differential rotation on the maximum mass of neutron stars (strange stars). We numerically construct stellar models using a highly accurate relativistic code based on a multi-domain spectral method. We find much larger mass increases for strange stars than for neutron stars for the same degree of differential rotation.